heart rate variability for cyclists

New Heart Rate Variability Recommendations for Cyclists

In an era when athletes are inundated with data from power meters and wearable sensors, it’s important to be selective about the data you pay attention to. Not all data is equally valuable, nor are all sensors accurate and consistent enough to provide data worth listening to. Of the options available, heart rate variability for cyclists (HRV) appears to be one of the most useful for gauging fatigue. Dr. Marco Altini, PhD, a leading HRV researcher and creator of the HRV4Training app, recently presented at a CTS Coaching Education seminar. Here are some of the practical takeaways for cyclists.

What is Heart Rate Variability (HRV)?

When your heart beats 60 times per minute, those 60 heartbeats are not evenly distributed at a rate of one per second. There are minute variations in the timing between beats. This is caused by a constant balancing act between your sympathetic and parasympathetic nervous systems (SNS and PNS, respectively). The SNS is your ‘fight or flight’ system and the PNS acts to maintain homeostasis. When you are rested or not stressed, the PNS can respond to minor stressors quickly. This leads to greater variability between heartbeats. When PNS activity is suppressed by fatigue or stress, your heartbeat is less responsive to changing stimuli. As a result, HRV goes down.

The problem is, the factors affecting heart rate variability for cyclists are more complex to conclude, “Higher HRV is always good, lower HRV is always bad.” How and when you measure HRV matter, and the context surrounding the measurements must be considered as well.

Measuring HRV

HRV should be measured either first thing in the morning or continuously throughout the night as you sleep. Morning measurements are typically taken manually by either using a smartphone camera, as with the HRV4Training app, or a heart rate monitor capable of capturing HRV. Overnight measurements are taken by wearable sensors. Preferred sensors, according to Altini, include Whoop, Oura, and Garmin. The data is not perfect, but it’s closer to electrocardiogram reference data than an Apple Watch, which is not recommended.

Why measure HRV instead of resting heart rate? HRV is more sensitive, meaning factors that might cause minor or imperceptible changes in resting heart rate cause a more noticeable change in HRV. This may be important for aging athletes who experience less of a change in resting heart rate due to fatigue. Alcohol consumption also disrupts HRV to a greater extent than resting heart rate.

“Normal” HRV Values

An athlete’s absolute HRV values are highly individual. As a result, there aren’t ‘normal’ values for HRV. Rather, what’s valuable is an athlete’s acute HRV relative to his or her long-term data trend. To make reasonable decisions based on your HRV, you’ll need to commit to recording daily measurements for at least two months.

When to measure HRV

Some of the most interesting takeaways from Dr. Altini’s presentation involved caveats to the standard guidance to measure HRV in the morning or continuously overnight. First, the recommended protocol for morning measurements is: wake up, use the bathroom and return to your bed, then measure your HRV for 1-5 minutes while sitting up. Why does Altini recommend sitting up instead of prone? HRV measures how well your PNS responds to stressors and return to homeostasis. Sitting up creates a small orthostatic challenge for your PNS to handle.

If you use a wearable device to measure HRV overnight, ideally the device should measure continuously or very frequently. HRV changes with sleep cycles. With continuous measuring, the variations even out. But if you take infrequent samples throughout the night, it is difficult to use the information.

Exceptions and Caveats

Here’s where things get interesting. What if you have a heart arrythmia? According to Altini, arrythmias introduce noise into your data and artificially elevate HRV. If you have frequent arrythmias during the night, your overnight data may not be usable. People with arrythmias may be better off measuring HRV in the morning. By doing so, they can choose to take the measurement when they are not experiencing arrythmia.

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If your wakeup routine is unpredictable, as may be the case for first responders (i.e. firefighters) or parents of small children, an overnight measurement may provide more consistent HRV data. On the other hand, if you are a shift worker and have variable sleep and wake times, take your measurement when you wake up. This at least creates consistent conditions, taking the measurement after a known period of sleep.

What to do with HRV Data

Measuring HRV consistently over a long period of time helps identify trends in the data. This is important for establishing your normative range, so you can tell when your values deviate significantly from your own normal.

One of Dr. Altini’s most important recommendations was to consider “stable HRV” to be good, rather than “high HRV”. If you are recovering well from workout and lifestyle stress and adapting to your training, your HRV values will stay relatively stable day to day, or on a 2- to 3-day rolling basis. When there’s a large deviation from normal, either a spike or a drop, take note. And always consider HRV along with subjective feedback about how you feel.

If HRV has any predictive value, it’s that a drop in HRV can indicate you’re likely to perform poorly. Yet, the inverse doesn’t appear to be true. A sudden spike in HRV doesn’t indicate you are more likely to win. If your HRV drops, your subjective feedback is that you feel like crud, and your future training includes hard workouts, consider swapping for an easier workout or resting more. In competitions, however, athletes often defy low HRV values – perhaps caused by travel or pre-race jitters – to win. Perhaps take this as a sign to keep heart rate variability for cyclists in perspective. Many coaches hide HRV from athletes before competitions to avoid doubt and negative thoughts.

By Jim Rutberg,
CTS Pro Coach, co-author of “Ride Inside“, “The Time-Crunched Cyclist”, and “Training Essentials for Ultrarunning

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Comments 12

  1. Pingback: Trainright Guide to Heart Rate Training for Cycling - CTS

  2. Nice article,
    Attention if you wat just before sleeping(drinking alcohol as well) will affect the heb enormously.
    Try and see the difference..
    Just an extra thought

  3. Pingback: New Study Reveals Holes in Wearable Device Scores - CTS

  4. I recorded it for 3 months and 4 months on two separate occasions and found no rhyme or reason in the results. The days the program said “rest”, I may have felt great or tired and again when it indicated I was ready to push, I may have felt tired or great. My perceived feeling as I climbed on the bike was the best indicator of performance 95% of the time. Evaluating workload over the past several days was a pretty good indicator of how I might feel tomorrow. As a 75-year-old cyclist I’m usually looking for something to help with performance or motivation and I found HRV to be as useful as an Air Resistance Power Meter. I used Elit HRV.

  5. Anch’io uso tutte le mattine la misurazione della HRV, ma leggendo i vari approfondimenti, mi viene un dubbio: ma è necessario effettuare le misurazioni tutte le mattine o si può farlo a periodi. Quali sono i consigli in merito?

  6. I have tried following my HRV several times (for a couple of months each time). What I discovered, consistent with your comments, is that a really low score did signal that I was overtrained (but more frequently just overstressed from work) and that high scores were not very helpful. The problem was that the HRV couldn’t seem to tell the difference between mental and physical stress, whereas changes in my resting heart rate and keeping score of my Strava training stress levels gave a much better sense of how hard to train. Overall, the biggest learning I have had as an aging athlete is that it is relatively easy for cyclists to over-stress the heart, particularly through long many hour workouts, and that shortening my time on the bike and increasing my weight and HIIT training allowed me to retain higher power levels without putting too much strain on heart or blood vessels.

  7. Your final comment mentioning race day low HRV values was right on the money! I’ve been tracking HRV for several years now using EliteHRV and I always have a low HRV on race days, no matter how good I’m tapered and rested. Didn’t realize pre-race jitters could throw it off so far, because I’ve usually done very well on days when the program suggested a rest/recovery day.

  8. Whoop interpreted my arrhythmia as recovery. Also I would wake up full of dreams with a report that I had zero REM sleep. I’ll stick with my regular old HR monitor and pay attention to how I feel.

  9. My watch added it and I was going to ignore it but can’t help looking every day. I do find it follows how I feel, low sleep score, high heart rate is going to have a low HRV. I am only 47 and don’t likely do as much cardio as the other CTS readers. I’ll be interested to see how it changes in the summer when I am cycling more.

  10. Hi Jon!
    Tell me more about you. When was pacemaker procedure done? Why was it done? Do you stick with regular device checks? Years cycling? Road? Trail? Age? VO2max? Meds? What is MAX HR set at? Do you compete?
    Did you speak to your cardiologist about tracking HRV? Also, there are other home tracking devices for cardiac folks.

    If you were my client, I would want to know more about you. But generally speaking, as Jim stated, consistency in time and position of readings with your current tracking device is key. I’m sure that you track your HR responses and RPE (Rating of Perceived Exertion) during training, and keep a log of meals, fluids, sleep quality, subjective energy levels, etc.
    For additional info on the accuracy of HRV with your specific pacemaker, go to the manufacturer.
    Hope this helps. Happy training.
    Pat VanGalen. M.S.
    Author: MedFit Cardiac R.E.H.A.B. Fitness Specialist Course.
    I post frequently on LinkedIn, and have reposted several CTS articles. Good stuff here at CTS.

  11. I have a 3 lead pacemaker that’s set to keep my heart rate at 60 for low! I don’t use a heart monitor. I typically listen to my body. Should I purchase a monitor!

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