Training Load and Nutrition Impact on HRV: 10 Week Data Analysis

Below is 10 weeks worth of my own training data that includes;

  • HRV – Collected daily on ithlete in standing position immediately after waking
  • HR  – Taken from the ithlete HRV measures
  • Load – Sets*Reps*Weight(lbs)
  • sRPE – Reps*RPE of session(1-10 scale)

All data is presented as weekly mean values.

HRV & Load

HRV & Load


HRV & sRPEHR & LoadHR & Load






– Training volume in weeks 1-5  involved 3 straight working sets for main lifts alternating between weeks of 5’s, triples and singles. Working weight for each set was predetermined based on previous week but would be adjusted if need be. Training volume progressively decreases as working sets were reduced from 3 top sets to 1 top set. Assistance work was mostly just maintained during the reduced load period. Week 10 was more of a  true deload where all working set weights were reduced but only to about 80% while assistance work was reduced slightly as well. Keep in mind that volume for each week would vary based on whether I was performing sets of 5, 3,  or 1 for top sets.


– Even prior to week 1 displayed in the data, I had not taken a deload in quite some time (end of August). Performance (strength) had progressively been increasing and I didn’t feel the need so I kept at it.  My HRV was consistently averaging in the low 70’s which is quite low compared to my typical average of  about 80 (based on several years of data).  Once I started having some nagging soft tissue problems accumulate I decided to taper the volume.  I was seeing how my body and HRV responded to deloading keeping intensity high but just cutting volume. HRV trended back towards baseline though soft tissue problems weren’t quite resolved.

– Week 10 was Thanksgiving week and I traveled to my folks place. Training was reduced yet HRV decreased. I attribute this entirely to the drastic change in my nutrition during this week. Fruit and Vegetable intake decreased significantly. Processed foods and carb intake increased dramatically. It was an atrocious but delicious week of eating. This is not the first time that I’ve seen HRV change due to similar changes in eating.

– In the chart below you can see HRV decline during the high volume/load period followed by a progressive increase during the taper. This is then disrupted with a progressive drop during Thanksgiving week of binge eating. HRV then trends back up this week as eating improves and regular training resumes.

Trend 9 to 12_2013

– HRV and HR need to be taken into context when being used to guide or monitor training. Other stressors always need to be considered. Neither will ever perfectly correlate with training load as this would assume that only training affects the ANS. It also worth mentioning that HR reflected training load better than HRV in this case and simple RHR should certainly not be dismissed or overlooked.

– Acute changes in HRV/HR won’t always “make sense” or correspond to perceptions of soreness, fatigue, mood etc. (though they do quite often). The weekly mean values tend to provide a better reflection of training/life style. I don’t adjust training on a day to day basis basis until I’m approaching my top sets.

Why Assess the ANS?

I just finished watching a presentation by Andy O’Brien entitled “Modern Concepts in Program Design – A Systematic Approach to Individualization”. Andy O’Brien works with elite athletes including NHL star Syndey Crosby. His presentation is 28 minutes long and is truly worth watching if you work with athletes. After listening to his talk, you’ll understand why he works with such high level athletes. I’d also like to add that this is yet another great free resource put out by John Berardi and his team at PN. I have no problem endorsing a company that continually puts out top notch information for free. The thoughts in this post are inspired from the ideas and concepts discussed by Andy O’Brien.

In his presentation, Coach O’Brien essentially views program design as problem solving. Naturally, the first step in designing a program is assessing the athlete. An assessment allows us to form a needs analysis and determine limiting factors that impede progression.

An example was provided of a weight loss client who wanted to lose X amount of fat in time for a wedding. After the trainer decided that diet was not the limiting factor, emphasis was placed on increasing calorie expenditure. What would appear to be a very effective program for improving body composition was prescribed (resistance training, aerobic and anaerobic conditioning, plus a thermogenic supplement). The results however were quite surprising. The client in fact gained fat after several weeks. The reason? Incorrect identification of the limiting factor.

It turns out that the client had a significant ANS imbalance of sympathetic predominance. Even before the exercise program, the nature of her work and lifestyle was highly stressful. Adding intense exercise 5 days/week only further increased this imbalance resulting in unfavorable hormonal responses and poor adaptation to the program.

O’Brien mentions a related study by Messina et al. (2012) entitled “Enhanced parasympathetic activity of sportive women is paradoxically associated to enhanced resting energy expenditure”. Unfortunately I do not have access to this text at the moment but here is an excerpt from the abstract; “These findings demonstrate that resting energy expenditure is higher in the athletes than in sedentary women, despite the augmented parasympathetic activity that is usually related to lower energy expenditure.”

This is one example of why it is important to assess the ANS. I think there are many folks who reject HRV as a useful metric in monitoring athletes or individuals. Perhaps this is because there is a misunderstanding of what the data is telling us or perhaps because interpretation of the data is difficult. Maybe it’s a compliance issue. Regardless, in my opinion, an objective measure of ANS status requires at the very least, periodic assessment for several reasons.

We measure strength, power, body comp, etc. yet ignore one major component of the body that largely acts as a moderator in training response and adaptation. HRV is likely the cheapest and most efficient non-invasive tool we can use to acquire ANS information.

To be clear, I’m not saying that HRV is first in the hierarchy of assessment (if one exists). I’m merely saying that the ANS plays a huge role in our health and performance and requires monitoring and assessing just as much as performance and body composition. How can we rule it out as a limiting factor if we don’t consider it at all?

Reflections, Thoughts & Some HRV Data Analysis from 2 Athletes

This week Carl Valle had a great article posted on Mladen’s site here. It’s definitely worth the read if you train athletes. This article inspired me to reflect on where HRV fits in to training, for whom it may work best for and why. I monitor HRV in a very small number of athletes who are the minority of the overall pool of athletes I work with.

To get the most out of HRV tracking, I believe it should be measured daily, in the morning after waking. With ithlete this requires less than 2 minutes of your time to perform the measurement and make any comments, input training load, etc. Though this is a simple task, it is not easy to get full compliance from individuals. Therefore, I don’t even consider getting an athlete taking measurements unless he possesses a great deal of intrinsic motivation, is responsible, reliable, and perhaps most importantly, is interested. Though I would prefer they know nothing about the device, it’s hard to convince people to commit to using it every day if they don’t understand why. After a few sessions I will mention it to them and give them some basic details. If they appear interested or ask if they can use it then it’s a go.

I have several motivations for tracking HRV in select athletes. Below, these motivations are listed with some follow-up thoughts and elaborations.

  • To observe ANS response to training, daily stressors, recovery modalities, etc.

What was HRV score the day following a workout? What else did the athlete do that day that may influence this score? What has the overall trend been that week (positive or negative)?  I like to compare HRV score to other training status markers like strength levels (did he hit target weights for the day?), movement ability (how does he look during warm-ups, jumps, etc.?), perceived recovery/readiness levels (Does he feel great when HRV is high, when its low?), etc.

This motivation serves two purposes.

  1. It gets the athlete more engaged in his life style and training (more on this in a bit)
  2. It satisfies my curiosity. I’ve got questions I want answered.
  • To observe HRV trends over times of illness, injury, etc. to determine if there were early warning signs in the trend and if the trend reflects recovery/return to play readiness.

In the event of an injury during practice or competition, what was the trend indicating? In the past year or so I hurt myself once during training and it happened with 60% of my 1RM during squats (hardly a threatening situation). My HRV that day was well below baseline. Possibly a coincidence, or possibly injury risk is heightened when HRV is really low. To my knowledge, there is no research on this in human athletes, but this seems to be the case in race horses. I discussed some very interesting research by Dr. Christine Ross in this post from last winter.

Here’s an excerpt from that post.

“Dr. Christine Ross monitored the HRV of 16 competitive race horses, all of which were in training. Of the 16, 13 had HRV readings that were associated with pain, fatigue, illness or injury. It was stated that even though the horses appeared healthy and energetic, they were considered “at risk” based on their HRV. There were no outward signs or symptoms to suggest these horses were currently sick or hurt. Within 3 months, 12 of the 13 at-risk horses got injured or sick requiring veterinary intervention and cessation of race training.”

Furthermore, I work with plenty of football players and hockey players who by nature are at risk of concussion. What insight can HRV provide regarding recovery and return to play after concussion? (Perhaps a post on this in the future)

  • In rare cases, to manipulate training if HRV has been consistently below baseline and the athlete displays signs of fatigue.

This is an interesting topic. Working with an athlete is rarely long term. In many cases you may only have 6-8 straight weeks of consistent training before interruption. That means we need to get them better quickly. Getting better can be defined in many ways but in the training realm this means improving strength, speed, power, work capacity, etc. To do this we need to apply stress. In some cases, a lot of stress, of various kinds. Naturally, HRV will drop. The organism has to work hard to adapt to the stress (and thus improve). We don’t have time to wait for “optimal” recovery and this is likely not even desirable.

Let me use an example. Below is the HRV trend of a 25 year old hockey player I’m working with. He’s come to me to get in shape for a try-out he’s been invited to for a pro team in Germany.


He is a former NCAA hockey player and has been training relatively consistently throughout school. After this summer he thought he was done with competitive hockey and stopped training however he did start playing men’s league hockey.  Since he hasn’t been training I knew we’d probably see some pretty big downward deflections after our first few workouts. He missed a few mornings of HRV measurements but it’s been about 2 weeks since we started. The “week change” is -8 and his HRV trend is steadily decreasing. His strength is steadily improving as is his conditioning. He’s adapting fast and re-acquiring lost strength and fitness. Training loads are steadily increasing every week. Now that it’s Christmas I expect to see his HRV bump back up due to some extra rest and likely extra calorie intake. So long as HRV approaches baseline levels after a few days of rest then I think things are looking good. However, if HRV continues downward I will evaluate performance markers and make adjustments if necessary. The physical stress load is high as reflected by his HRV but it’s only been 2 weeks and his performance markers are improving. The weekly trends will likely continue to decrease until about 2 weeks out from the try-out at which point I’ll steadily reduce loads. HRV should climb back up and fatigue should dissipate. This is what happens when I have a relatively short period of time to work with an athlete.

In contrast, the trend below is of a high school sprinter I’m working with. He trains with his sprint coach and works with me for recovery/restoration, mobility, etc. He has a sub 11s 100m time and is one of the fastest high school sprinters in Canada. He is much more long term and his training load reflects that. His weight training volume has been reduced quite a bit and has transitioned into more sprint work and power development in the weight room (controlled and implemented by his Sprint Coach).

ZW Trend

This is an athlete who takes care of himself and is extremely motivated to get better, to say the least. He reports that training is going well, he’s hitting PR’s and it looks as though he’s handling training almost too well. Higher loads would be likely well tolerated. If I can just start getting him to get to bed at a decent hour on weekends he’ll be doing everything right.

In both cases the athletes have learned how lifestyle factors outside of training effect their recovery, soreness levels, etc. This is directly attributed to seeing their HRV trend, recognizing what events may have caused the additional stress and re-evaluating there decision making. One of the main things I like about HRV is that it forces you (and the athlete) to be more engaged in the process. It allows them to see how their actions (good or bad) can effect the quality of their training and their progress.

Final Thoughts

Having HRV records as an objective measure of training status helps guide the training process when taken with other markers of performance and fatigue. If the athlete is a high level athlete, mature enough to handle daily measurements and wants to use it then I am all for it. I don’t use it with many athletes because it would be a waste of time and energy for both parties. However, with the right athletes it can be a great tool to for monitoring training.

Recent HRV trend analysis and a new collaboration

As I try and further my understanding of the seeming incomprehensible autonomic nervous system I try to simplify the role HRV may play in monitoring athletes. There is one main issue I’m having; I don’t yet fully grasp the ANS (does anyone?) and therefore I still have a ton of unanswered questions.

I’ve noticed that there are some extremely intelligent people who are strong advocates of HRV usage as a monitoring tool. I’ve also noticed there are equally as intelligent people who are very skeptical and even doubtful of its efficacy and applicability. I’m doing my best to understand both sides of this argument. The best I can do to contribute to this discussion (at the moment) is draw attention to research and offer personal experience.

It’s been a while since I’ve posted and discussed some of my HRV trends so today I will do this as well as share some observations a colleague of mine has made at McMaster University.

Below is a screen shot of my HRV trend from the last 30 days:

  • Horziontal Blue Line = HRV Baseline
  • Vertical Purple Bars = sRPE (absence of these indicate no training)
  • White Lines = Day to day HRV scores

Training structure has been as follows:

  • Monday – Squat
  • Tuesday – Active Recovery
  • Wednesday – Bench Press
  • Thursday – Active Recovery
  • Friday – Deadlift
  • Saturday – Off
  • Sunday – Off

Strength workouts range from an RPE rating of 7-9 while the low intensity “recovery” days range between 3-5.

dec 2012 trend


  • Much of what I’ve seen is consistent with what I documented in this post so I won’t discuss these in too much depth again.
  • Normally my HRV will be at or above baseline after a weekend (no training). In the first weekend you see my HRV dropped quite a bit Monday morning. I assume this is because I was away that weekend and I spent much of Sunday in the car and then was frantically trying to get caught up on things once I got home before Monday.
  • I trained at an sRPE of 8 on Monday and as expected another drop and a red indication for Tuesday. Active recovery typically will bump HRV back up the next day however Tuesday night I unknowingly went to sleep with my friends cat hiding under my bed. Around 2am I got a startling wake up as the animal tried to snuggle with my face. It took me nearly 2 hours to fall back asleep after. HRV that morning is another red and I feel like crap. I take a deload day on Bench  (sRPE 7), sleep well and HRV comes back up the next morning.
  • Things remain consistent during the week shown in the middle of the trend. Moderate dips in HRV in response to sRPE 8’s with returns to baseline after low intensity days. HRV is high after a restful weekend.
  • The following week I start doing a little more work in my workouts (more heavy sets) and therefore a higher sRPE rating (of 9). Along with higher amounts of soreness and perceived fatigue I saw larger dips in HRV the following day. On Friday (deadlift day) I keep things conservative due to previous lower back injuries and perform an sRPE of 8 and see less of a drop in HRV the next day. I’m happy to report that the back has been feeling good and I have started deadlifting again recently. I stopped deadlifting  for a while as I was experiencing pain during the lift (no surprise it was an underactive multifidus) Video below of a recent deadlift.
  • HRV is high after a restful weekend. sRPE of 9 on Monday (squat) of the last week shown on the image and I again see a larger dip in HRV (today). Will do some low intensity stuff later on after work.

Collaborating with Steve Lidstone at McMaster University

Since moving back to Canada I’ve been working on getting an HRV project going with Steve Lidstone, the head strength coach at McMaster University (a huge rival of mine in my football days). After some e-mail discussions I sent Steve an ithlete to try out. After a few weeks Steve sent me this update;

“I’ve been monitoring my HRV for 3 weeks now every morning.

I started off with HRV at 88 with a HR of 60bpm.

In times of poor sleep (we have 2 kids ages 2 & 4) or high stress my HRV has plummeted to 55 and resting HR of 79.

It is also interesting to me as I am in my 5th week of post concussion symptoms. When my HRV is low my symptoms are escalated.”

At this point we’re looking at getting two of his teams started with ithlete (about 8 players in total). Should make for some good data to discuss.

Planning the Recovery

The inclusion of HRV monitoring into my training has caused me to change my perspective a fair bit on the subject. It has also provided me with a lot more questions than answers, but I don’t consider this to be a bad thing. My main interest and focus has always been on how to increase strength. A quick look over at my bookshelf and I can see that I have accumulated a small library on the topic. In pursuit of increasing my own strength I’ve been on an ongoing mission to discover and learn the best training methods and programs that can get me stronger. Today’s post is about the polar opposite of what I’ve been spending years of my life on learning. That is, the opposite of training. HRV monitoring has inspired me to consider not just appropriate planning of training loads, but the planning of recovery and restoration modalities – the opposite of physically stressful training.

First I’d like to assert my current position or philosophy on training; Your workouts are only as effective as the quality of your adaptation to them. This is analogous to the nutritional concept of being not necessarily what you eat, but what your body assimilates or absorbs from what you eat (I believe it was Poliquin who said that). I believe that the more advanced you get with your training, the more this statement applies. To elaborate on this concept, if you’re out-training your body’s ability to favourably respond to the stress, it doesn’t matter how perfect or scientific your program is. This is what makes monitoring something like HRV so invaluable. Understanding complex training methods and being able to apply them is simply one facet of the overall process. The recovery process also requires planning, structure and strategy.

At this point I wish I could tell you how to perfectly strategize and plan your recovery but I simply don’t know the answers. What I do know, and I’m stealing this term from Mladen Jovanovic, is that a complementary approach to training is necessary. Putting a ton of time into devising your next training cycle must involve considerations of recovery processes. This is not to say that that you must actively perform some mode of recovery at all times but rather that it would be wise to consider matching increases in training stress with a logically applied increase in recovery strategies to assist in the recovery and adaptation process.

Below is a brief list of factors I’ve been considering more when planning my training/recovery process;

(Note that the following are simply stated to provoke thought, I’m not recommending anything in particular as I’m not qualified to do so)

Sleep: Quality and length are obviously important during all phases of training. Can Inclusion of daily naps at certain times/phases be of any benefit? What about time of day training? Myllymaki and colleagues (2011) found that late night exercise resulted in higher heart rates during the first few hours of sleep compared to control however no effect on overall sleep quality or nocturnal HRV was seen. Perhaps post exercise static stretching would further reduce HR post-exercise (see below: static stretching) – You can monitor your sleep with mobile apps although I have yet to do this.


–          Macronutrients, caloric intake (matched to body composition and/or weight class goals), manipulation of macronutrients according to training phase (i.e. higher volumes accompanied with higher carbohydrate intake?)

–          Micronutrition (Ensuring adequate vitamin and mineral consumption. Does this change with variations in training load?)

–          Anecdotally I can say that I almost always see an acute spike in HRV the morning after a night of purposeful overeating.

–          Ingesting foods that are anti-inflammatory? Reducing or eliminating foods that are pro-inflammatory? For a discussion on nutrition and HRV see this post.

Supplements: Inclusion of ergogenic aids at appropriate times; vitamin D over winter; supplemental forms of Zinc, Magnesium, C, etc. Rather than taking certain supplements year round would they be more effective by being cycled in at certain times?

Massage: Beneficial in periods of high loading? Massage has been show to acutely increase HRV in athletes (Arroyo-Morrales 2008) and healthy subjects (Delaney 2002). See Patrick Ward’s site for more insightful discussions on HRV and massage.

Static Stretching: I understand that static stretching is a bit of a hot topic and is widely debated. But static stretching post-workout increases HRV (Mueck-Weymann 2004, Farinatti et al. 2011) and therefore more rapidly initiates the recovery process. How much of an effect this may have on the overall process I cannot say but it’s worth considering.

Cold Water Immersion: The effect this has on recovery is debateable (see a good article by Dr. Marco Cardinale here) but it does appear to enhance parasympathetic reactivation post-exercise in athletes after supra-maximal cycling exercise (Buchheit et al 2009). The psychological effects of this shouldn’t be ignored either. Does it matter if something like this actually helps if the athletes wholeheartedly believe it does? When I played football during my undergrad the cold tubs were a MUST during training camp. None of us questioned this. If we sat in the cold tub we thought we helped our recovery. If we didn’t we would expect to be more sore the next day. Placebo effect?

Active Recovery: From personal experience I’ve seen a noticeable difference in perceived recovery, also reflected in my HRV scores with active recovery work. However, incorporating active recovery at certain periods and removing it from others may enhance its effects.

To reiterate, the above modalities may or may not be the answer to continued progress. However, their strategic planning and application throughout training may allow you to better handle the higher training loads necessary to stimulate further progress. We periodize the amount of stress we apply to our body’s, why not also periodize modalities that theoretically may enhance our ability to tolerate that stress at the appropriate times?

For the strength coaches reading this, I’d be curious to know how much thought and planning goes into this aspect of your training with your athletes. Do you have your athletes use different recovery interventions? When and why? Do you monitor this?

I am still young and relatively inexperienced compared to many of you that may be reading this. I can say that from my experience coaching strength and conditioning at the collegiate level that monitoring can be an extremely arduous task given the limited amount of time available with the athletes. Not to mention, the process of monitoring is time consuming in and of itself, making it difficult to do when you’re responsible for several teams.

Leave me a comment or send me an e-mail to continue the discussion.


Arroyo-Morrales, M. (2008) Effects of myofascial release after high-intensity exercise: A randomized clinical trial. Journal of Manipulative and Physiological Therapeutics, 31(3): 217-223.

Buchheit, M. (2009) Effect of cold water immersion on postexercise parasympathetic reactivation. American Journal of Physiology, 296(2): 421-427 Full-Text

Delaney, J. (2002) The short-term effects of myofascial trigger point massage therapy on cardiac autonomic tone. Journal of Advanced Nursing, 37(4): 364-371

Farinatti, P. et al (2011) Actue effects of stretching exercise on the heart rate variability in subjects with low flexibility levels. Journal of Strength and Conditioning Research, 25(6): 1579-1585

Mueck-Weymann, MG., et al (2004) Stretching increase heart rate variability in healthy athletes complaining about limited muscular flexibility. Clinical Autonomic Research, 14(1): 15-18

Myllymaki, T. et al (2011) Effects of vigorous late-night exercise on sleep quality and cardiac autonomic activity. Journal of Sleep Research, 20(1): 146-153

HRV Guided Training, Periodization and Training Variables

Here are some things to consider when planning your daily workouts guided by HRV;

  1. What load of work can my body handle today?

    I primarily use HRV to determine this, however lately I’ve been doing some morning tap tests as well to see what I find (Tap Test App for iPod).

    I like to break adaptive capacity rating up into 4 categories

    1. High – Increase loads
    2. Baseline – Proceed with planned load (moderate to high)
    3. Below Baseline – Reduce load
    4. Low – Rest or Active Recovery

      *In this context load refers to a combination of volume and intensity of training

    iThlete provides color indications for each of these days to simplify interpretation;

    1. Green = High
    2. White = Baseline
    3. Amber = Below Baseline
    4. Red = Low

      Here is a “Baseline” HRV Score measured this morning

  2. What is the goal of the current training phase?

    Accumulation of volume? Intensity? Weight gain? Weight loss?

Your training plan will obviously reflect your training goal however I’ve learned that it’s wise to make necessary adjustments to load in response to the present day’s adaptation potential. The following are a list of variables that I like to manipulate on a daily basis according to HRV score within the context of the training phase/goal.

  1. Volume (number of sets and reps performed with the main lift and assistance work)
  2. Intensity (the amount of weight on the bar)
  3. Rating of Perceived Exertion (how close to failure I get with my sets)

Here is an example of how I manipulate these variables based on training phase and HRV score.

Example: Volume Phase in a Block Training system:

I consider total reps in the 15+ rep range (usually no more than 25 total reps) to be high volume. This can be 3×5, 5×3, 4×4, 5×4, 6×4, 7×3, etc.

  • If HRV is high: I will typically take the higher end of the volume scale using higher sets and lower reps. RPE falls between 9-10 (10 only on last set).
  • If HRV is baseline: I will work in the middle set/rep range of the volume scale. RPE stays around 9.
  • If HRV is below baseline: I’ll stick with the lower end of the volume scale (no more than 15 total reps) with RPE staying around 8.
  • If HRV is low: Active Recovery work, no lifting.

With this set up I can still accumulate volume as long as HRV isn’t low. If I take care of my sleep, eating and overall stress levels, low day’s usually only occur the day following a training session. This is why I lift every other day and perform active recovery on “off” days. The idea is to increase the volume when HRV is high with higher intensities (<3 reps, higher RPE). When HRV isn’t quite where we would like it, we still accumulate volume, but with less intensity and a lower RPE.

Another method I’ve used for manipulating loads on a daily basis is to use more of an undulating periodization approach as opposed to a block approach. With this approach volume, intensity and RPE are constantly changing from workout to workout.

Example Undulating Periodization Approach;

  • If HRV is high: Both volume and intensity will be higher (ex: 6×2 with RPE 9-10)
  • If HRV is baseline: Reduce volume OR intensity (ex: 3×3 with RPE 9 or 3×8 RPE 8)
  • If HRV is below baseline: Intensity AND volume is reduced (ex: 2×4 RPE 8)
  • If HRV is low: Deload workout/active recovery

With this system we increase total load when the body is prepared to handle it better and back it off when necessary. Higher HRV days will involve lower rep ranges to allow for a higher %of 1RM whereas lower HRV days will have higher reps to reduce % of 1RM.

Keep in mind these set ups were for the purposes of increasing strength. Through constant experimentation and evaluation I’m improving on my approach to training. These set-ups aren’t perfect but they worked well. I’m presently using the block approach illustrated in my first example in my current training.

In a few weeks I’ll hopefully get a good post up on how the tap test fits into my program design. I’m looking to see how it correlates to strength, HRV, RPE, etc.

HRV, Adaptation, Progression, Training Adjustments

I’ve been reviewing my HRV trends over the last few weeks to analyze how my body is handling my current training set-up. I’ve been noticing smaller drops in HRV the day following a heavy workout (sRPE9). In some instances I’ve seen a small hike in HRV the following day. Today I will provide a few thoughts on what may be happening as well as some thoughts on things to consider when analyzing your data.

It’s been demonstrated in the research quite clearly that HRV reflects recovery status in both weight lifters and aerobic athletes. Therefore, it’s reasonably safe to say that your HRV score the morning after a workout is reflecting how stressful the workout was. However, it’s extremely important to consider other variables that can affect recovery (other stressors). So taking this into consideration, HRV score reflects not so much the stress of the workout, but rather how well your body was able to respond to it since the cessation of yesterday’s training session (assuming the workout was the biggest stressor of the day).

Let’s say you performed an intense workout that you rated a 9 out of 10 on an RPE scale. The following day your HRV score will depend on the following key variables;

Nutrition: Did you provide the resources for your body to recover from the session? Proteins for structural repairs of damaged muscle fibers, fats for overall calorie intake and hormonal support and carbohydrates for glycogen re-synthesis. Was overall calorie intake sufficient? 

Purposeful Rest/Relaxation: Following the workout did you start the recovery process by relaxing, hot shower, etc.? This will allow the parasympathetic nervous system to get the recovery process underway.

Compounding stress: In contrast to the above, did you add further stress to your body? How physically active were you? What stressful events occurred and how bad were they?

Sleep: How restful was your sleep? How many hours? Were there disturbances?

Aerobic Fitness/General Physical Preparedness: The more aerobically fit you are, generally the better your HRV will be. The higher your work capacity, the more stress your body can handle. In my experience, in effort to increase performance in a given quality, it’s important to consider the overall fitness of the individual as this can limit and effect recovery, training frequency, volume, intensity, etc.

Familiarity of the Training Session: What type of workout was it? Have you performed this workout recently with similar loads? In other words, has your body adapted to the workout structure which therefore reduces the stress on the body?

I would like to elaborate on the last point since the above are pretty self-explanatory. When considering HRV response to a training session, it’s important to evaluate if you are introducing a new stress to the body via new workout structure, type and familiarity of work (aerobic, anaerobic, running, rowing, resistance, etc.). It’s been my experience that a new workout structure or unfamiliar training will create a larger drop in HRV. This is obviously because your body is not accustomed to the type of work and must work hard to adapt and recover. For example, the first time I performed a conditioning session this past year my HRV dropped immensely. However, each conditioning session thereafter provoked less and less of an HRV drop. HRV reflected my progressive adaptation to the stress. Even though the workouts may still have been perceived as hard, the body is familiar with the stimulus and homeostasis is quickly restored.

Some follow up questions based on the above discussion;

  1. Is the workout still effective if it does not provoke a marginal stress response (drop in HRV)?
  2. Should we use HRV as a guide to adjust and make changes to training structure to avoid staleness/plateau (periodization)?

In addressing question 1, it’s important to first evaluate training progress. Check your workout log. Are you still getting stronger/faster/running further, etc (whatever your training goal is). If the answer is yes, continue. Other factors and adaptations are obviously taking place.

In response to question 2, we need to carefully examine all of the above factors that affect an HRV score. If your nutrition is on point, you are reducing compounding stress, sleeping well and so forth, we can assume that the following day’s HRV is a reflection of your response to the training session.

If you’re experiencing a plateau it’s time to consider altering training. If you are a strength athlete you have a few options. Adjust volume or intensity. Adjust training sequence/frequency. Make adjustments to the lifts themselves. For example, add a pause to your bench or take it away, rotate assistance lifts, add or remove an exercise. Obviously only one major adjustment is needed. Evaluate progress, keep track of HRV trends and see if that made a difference. It’s also important to consider that training progress in more advanced athletes/lifters is non-linear. Therefore, don’t make drastic changes at the first sign of plateau. It’s okay to repeat workouts. Use your judgement on if a change is needed.

I will continue with my current training structure and set up to see if progress continues or stops and if HRV trends change or stay the same. Once I can evaluate more of my data I’ll write up a report.

HRV in a Team Setting

Monitoring athletes throughout training provides coaches with extremely valuable information regarding each athlete’s responsiveness to imposed training loads. Most would agree that the main objective for any coach (at competitive levels) is to win. If you fail to do this you will likely be fired.

I think we can also agree that bringing our athletes to peak physical condition (as it applies to their sport) will increase our chances of winning. To do this effectively, physical preparation in both team practice and S&C must be balanced. The right balance of training loads will yield optimal adaptation.

Adaptation is Key

Training (technical and physical) is a stressor our athletes must recover from. If the stress is too great, adaptation will be compromised. If the stress is insufficient, improvements will not take place. Therefore, the training stimulus must be within our athlete’s ability to adapt, allowing for performance improvements. This is pretty well understood by most coaches. However, the ability to balance loads effectively is much less understood. Too often coaches rely on pre-planned training regime’s that fail to take into account each athletes individual adaptive capacity. It is the coach’s responsibility to critically evaluate several issues that arise throughout the year such as;

  • Why did an athlete get hurt?
  • Why did an athlete fall ill?
  • Why is the team seeing decrements in performance?
  • Why are we not performing to our abilities throughout the entire match?
  • Why are certain athletes improving while others are regressing?

I’m sure you can think of more questions to consider.

Monitoring HRV in Sports Teams

Hap, Stejskal & Jakubec (2010) set out to monitor the HRV of 8 competitive male volley ball players (approximately 18-25 years old) over a 7 day microcycle during training camp. The 7 day camp had the athletes partake in 11-13 volleyball practices and 14-16 conditioning sessions. The training was entirely pre-planned and HRV scores were not shared with players or coaches. HRV was measured once each day for a total of 7 times (6 measurements were performed in the morning immediately after waking and 1 measurement was performed under controlled conditions in the afternoon).

The results showed 2 athletes demonstrated above average ANS activity (high HRV) throughout the entire week. In these athletes, the load was below training capacity and higher training levels could have been tolerated to further increase performance. In 4 athletes, HRV scores decreased to the lower end of average. This indicates a moderate level of fatigue and that training load corresponded to their training capacities. In the last 2 athletes, HRV scores were negative (below average). Training stress was too high in these individuals and reduced loads and recovery/regeneration modalities would’ve increased the quality of their training.

In this instance, the pre-planned training program was appropriate for 50% of the team. 25% were overtrained and 25% were undertrained.

In another study, Cipryan & Stejskal (2010) decided to monitor the HRV of competitive hockey players. There were 18 subjects, 8 were junior level players (18 years old) and 10 were from the adult team (mid-20’s). Both teams underwent their own training and practice programs. HRV was measured twice per week in the morning (Mon and Fri) throughout the 2 month training program.

The results show that from the junior team, 2 players showed above average adaptation capacity. 1 player showed decreased HRV scores indicating high fatigue. Training was appropriate for 5/8 players. In the adult men’s team, 3 players showed higher HRV suggesting that more (volume or intensity) training would’ve been tolerated. 1 player showed decreased HRV. This player could not see an increase in HRV back to baseline levels because the training did not conform to his adaptive abilities. This player was at risk of more frequent health complications. This training program was appropriate for 60% of the team. 30% was undertrained and 10% was overtrained.

In the discussion, the authors proposed that athletes be separated into groups during training with 3 separate programs available. One program for athletes with low HRV (decreased loads) one program from athletes responding appropriately (moderate loads) and one program for athletes with high HRV (increased loads).

The last study that I’ll discuss has been mentioned before in previous articles that I’ve written. Cipryan et al. (2007) measured HRV in Czech U-17 male hockey players once per week in the morning over a 3-5 month period. In addition, the coaches were asked to rate each players performance on a scale of 1-10. The researchers found that as HRV increased, performance was rated better and correlated to more playing time. When HRV was low performance was rated lower. Performance correlated with HRV score.


What I found interesting was that in 2 of the above studies, HRV was monitored only once or twice per week and was still able to provide important data regarding training status. This makes the application of HRV in a team setting much more realistic. Daily measurements can certainly be done and would likely provide more accurate data but can prove to be difficult. The ability to perform HRV measurements are limited by; having access to valid and reliable measuring devices; having a qualified individual(s) to record and analyze data; having athletes capable of following measurement instructions. HRV applications on smart phones certainly would make this process much easier. These are much more cost effective and convenient.

It appears that pre-planned training certainly isn’t optimal for realizing athletic potential in athletes. Though this is very inconvenient for the coach, having the ability to adjust training prescription for certain athletes based on HRV can increase the quality of training and adaptation while decreasing health complications (illness, injury, overtraining).

How often do coaches punish players for poor performance with intense conditioning in practice sessions following a previous competition? How many coaches punish teams with physical conditioning due to team rule infractions? How often are ill or injured players returning to training and competition before they’re ready? Clearly these strategies require some re-evaluation. It is quite possible your training program, no matter how good it looks on paper, is only appropriate for 50-60% of your players.


Cipryan, L. & Stejskal, P. (2010) Individual training in team sports based on ANS activity assessments. Medicina Sportiva, 14(2):  56-62

Cipryan, L., Stejskal, P., Bartakova, O., Botek, M., Cipryanova, H., Jakubec, A., Petr, M., & Řehova, I. (2007)  Autonomic nervous system observation through the use of spectral analysis of heart rate variability in ice hockey players.  Acta Universitatis Palackianae Olomucensis. Gymnica, 37(4): 17-21.

Hap, P., Stejskal, P. & Jakubec, A. (2010) Volleyball players training intensity monitoring through the use of spectral analysis of HRV during a training microcycle. Acta Universitatis Palackianae Olomucensis. Gymnica, 41(3): 33-38

HRV response to perceived training load – Observations from 2.5 months of data

About two months ago the new version of iThlete was released with some really cool new features. These new features included;

  • The ability to rate your sleep on a score of 1-5
  • A comment section that allows you to make notes about the previous day’s events, stressors, etc.
  • The ability to input training loads that appear on your HRV trend chart so you can see how your HRV responds to your training
  • The ability to export data to drop box

Here is a video that shows the updated features;

The most significant addition in my opinion is the ability to track your training loads with your HRV trend. This really puts into perspective how stressful your workouts are. There is no specific method or formula that you have to use for your training load data. There are several methods that have been used in research to quantify training load, some of which I’ll describe below.

Training Impulse (TRIMP) – this is calculated using training duration, maximal heart rate, resting heart rate and average heart rate during the session

Session Rating of Perceived Exertion (RPE) for Endurance Athletes – Session RPE score x duration of exercise in minutes (for endurance training)

Session Rating of Perceived Exertion (RPE) for Strength/Power Athletes – Session RPE score x repetitions

*See Borrensen & Lambert (2009) for a more elaborate review and explanation of the above methods.

       Training Volume – Weight Used x Sets x Reps

Other methods exist, but these tend to be the most commonly used. In deciding how I would monitor my training I simply decided to use an RPE of the session, however, not like the method listed above. Instead, I simply rated my workout on a scale of 1-10 based on how hard, or how much effort I put into the session. I would consider volume, strain, RPE of my main sets, how hard I pushed my assistance work and so forth. I realize this isn’t the most valid or reliable measure of training load, but it’s been working well for me.

To give you an idea of how I grade my workouts, see below. This will make interpreting the charts I attach below of my trends much easier.

Session RPE of 10 – 3 or more top sets for my main exercise, RPE of 9-10 for each set, high volume of assistance work (3+ sets to failure), complete exhaustion by workouts end. I have yet to perform a 10 workout and likely never will.

Session RPE of 9 – 2-3 top sets for my main exercise, RPE of 8-10 for each set, moderate volume of assistance work (2-3 sets not to failure), considerable fatigue at end but not exhaustion.

  • I’ll typically perform these workouts when HRV is above baseline

Session RPE of 8 – 1-2 top sets for my main exercise, RPE of 8-9 for each set, low to moderate volume of assistance work (1-3 sets not to failure), moderate fatigue at end

  • I’ll typically perform these workouts when HRV is at the lower end of baseline

Session RPE of 7 – 1 top set for main exercise with an RPE of 8 or less, low volume of assistance work with reduced weight, minimal fatigue at end.

  • I’ll perform this workout when HRV is below baseline with an amber indication (deload)

Session RPE of 5 – No main exercise performed, light weight, moderate volume

  • This is what I’ve been doing on Sunday’s to hit delts and arm’s since I don’t do much work for them during my main sessions on Mon-Wed-Fri

Session RPE of 3 – Active recovery work for 20-40 minutes. This can be in the form of light jogging, sled dragging, circuits, etc.

  • I try and perform these workouts the day after each workout to facilitate recovery and maintain an aerobic base level of conditioning

Session RPE of 1 – Leisurely walk for 30-40 minutes. This can hardly be described as a workout but it’s more than a zero so I will log it when it happens.

  • This happens sometimes instead of an active recovery session.. usually when I’m visiting my folks as we’ll take a lot of walks.

So as you can see there is no sexy formula (I’ve never been a math guy anyway), but I’m pretty consistent and I’ve noticed some fairly common trends in my recovery (based on HRV). Below I have attached a couple screen shots of my HRV Trends with Training Load (Session RPE ala Andrew Flatt). The purple bars reflect training load (9 being the highest you’ll see) while the horizontal trend is my HRV daily fluctuations with the blue line representing my baseline.


  • See here and here for previous posts about observations I’ve made from monitoring my HRV
  • A session rated as 9 is almost always going to cause a pronounced drop in HRV the following day. This is why I don’t typically train on consecutive days.
  • If circumstance causes me to train two days in a row, I’ll use a Session RPE of 8. My HRV will usually drop moderately after the first workout out and drop even more after the second one.
  • During the passed 2.5 months I experienced approximately 16 instances where my HRV dropped enough causing an amber or red indication. The majority of these occurred the day after a session and therefore fell on a recovery day.
  • There were 5 days in which a red or amber indication fell on a training day and therefore out of the 2.5 months, I only deloaded for a total of 5 days. In the past I would typically take a week off after every 3 week cycle however with my new system of training I simply deload on a given day when my HRV is well below baseline.
  • The lowest dip on the graph (around 04/20) I purposefully trained harder than normal on a below baseline day (amber indication) to see how my body would react. The next day my HRV dropped even lower with a red indication. This, as well as other incidences from the past solidifies my stance that training hard when HRV is low delays recovery. You’ll see that it takes several days until my HRV gets back up to previous levels. This negatively effects future training sessions. In my opinion, it’s much better to reduce loads for one day to improve the effect of your following sessions as opposed to just training through a bad day and ruining the next few sessions. This is also what has inspired me to stop deloading at pre-determined times for pre-determined periods. There certainly is value in doing this as the body needs time to recover and adapt to weeks of hard training. However, with HRV monitoring, it seems (atleast to me, for right now) that you can get away with just reducing loads on days when HRV is low.
  • I’m presently the leanest I’ve ever been at my current body weight. I’m about 232lbs at 17%. The leanest I’ve ever been is 14.8% at 218 while the heaviest I’ve ever been was nearly 270lbs when I played collegiate football (I’m the ogre in purple below from back in 2006).

  • I’m presently the strongest I’ve ever been at this body weight.
  • I’ve been able to remain injury and illness free since using HRV to guide my training. I no longer experience any tendonitis in my elbows either which used to be a big problem.

Final Thoughts:

I realize that I may appear overly biased towards HRV’s usefulness in my writing. However, I feel that I’ve been training long enough to know when something’s all in my head (placebo) or when it’s actually making a difference. The science supports HRV (see here) and my experience up to and including the present also seems to support it. The whole concept of planning training in advance and sticking to it no matter what is not as effective as manipulating training on a day to day basis according to an objective measure of your body’s current adaptive capacity. This doesn’t mean you can’t have a general plan, it just means that you need to be prepared to make adjustments along the way to ensure the quickest and safest way to reach your training goal. HRV provides, in my opinion, the simplest and most accurate information to allow you to do this. I will continue with this method of monitoring and training since it has been so successful. I’ll be sure to provide another update in a few months.

Thanks for reading.

HRV for the recreational athlete and average person

Many of the people that I speak with about HRV lately are non-competitive athletes. They are however recreational weightlifters/runners who still take their training seriously (as they should!). Others include typical mom’s and dad’s who work and raise children, as well as other individuals just trying to get by. The purpose of this post is to explain why these individuals can still benefit a great deal from monitoring their HRV.

So why might the average person want to monitor their HRV?

First and foremost, HRV provides a very simple to use and inexpensive measure of the stress your body is currently experiencing. I’m going to use an analogy I learned from Joel Jamieson at the Central Virginia Sports Performance Seminar, that does a really good job of explaining this better.

Think of your current ability to handle stress as a bank account. Every time you take money out of your account (experience stress), you are reducing your overall balance of money (ability to handle more stress). Provided you always replace that money that you’ve withdrawn by depositing money back into the account (allowing for sufficient rest), your balance will remain steady. Now, if you withdraw too much money (experience too much stress) you can eventually go into debt (poor health). It will take much longer now to replace the money you’ve spent (return to good health) and lots of problems will start to arise. This is a position you obviously don’t want to be in.

So HRV is your ‘bank account’. Every time you experience stress (training, money problems, emotional stuff, etc) your HRV will reflect this by declining. When your HRV is below baseline levels, your ability to handle further stress is reduced. If you get enough rest, eat quality foods and so forth, you’re essentially putting money back in the bank. If you fail to do this, and continue to experience various forms of stress, you will start to experience breakdown. This can be in the form of suppressed immune system function, injury, weight loss (not the good kind), weight gain (not the good kind), low libido etc. There’s a good chance that many of you reading this are “in debt” due to the stressful nature of work, raising a family, paying bills, lack of sleep, poor nutrition, etc. Though you may not realize it, you may even be experiencing symptoms of this excess stress. Stress is typically the root that manifests itself into various forms of illness and disease when not controlled. I highly recommend checking out this book by Dr. Sapolsky titled “Why Zebras Don’t Get Ulcers” for a much more thorough explanation of the detrimental and deleterious effects of stress.

Think of your HRV score as a reflection of your current health. If you notice HRV declining over time, then your health is likely deteriorating. Think about those times when you’ve felt completely run down, gotten sick, and your training sucked. HRV monitoring can help you avoid these situations.

How can it do this? Simple really, when your HRV is low (and doesn’t seem to come back up after a few days) you need to purposefully reduce your stress. Cut back on the training, improve your nutrition, get some extra sleep, etc. Anything that you perceive as relaxing or rejuvenating will likely improve your HRV. This can be massage, a bath, yoga, etc. Once HRV has returned to baseline, ramp the training back up and get back to it. This will prevent you from overdoing it until it’s too late and you get hurt or sick.

Let me provide some real life examples that might hit home a little with you. Have you ever gone out for a run intending on doing a certain distance only to find that you’re struggling to make it half way? Perhaps your ankle is bothering you a little or you just can’t get a good rhythm?

Or for those that resistance train, how many times have you shown up at the gym intending on bench pressing a certain amount of weight only to find that your warm up sets feel like a million pounds?

I see and hear about this all of the time. I used to experience it too. However, by using HRV to plan and organize my training, I have entirely eliminated running into this problem. This is because I can typically predict when these types of days will happen based on my HRV score. Rather than sticking to the plan and attempting a hard training session when my HRV is below baseline, I simply plan a lighter workout or omit it all together to allow for the needed rest. Typically it only takes one day of reduced training to bring my HRV back up. If I ignore the warning my HRV is giving me however, it will take much longer for me to bring my scores back up and the workout is usually poor.

You certainly don’t need to be a competitive athlete to monitor your stress levels. Balancing your stress is crucial to your own health and longevity. If you feel that you may be under a lot of stress, physically, mentally or otherwise, you should consider monitoring your HRV to help keep things in check.

For a more elaborate description of what HRV is and how you can use it start here and here.