Can changes in HRV predict changes in running performance?
Buchheit et al.
Who, why and what?
An experienced team of researchers, led by Dr Martin Buchheit (Aspire Academy), set out to assess relationships between running performance and heart rate variability (HRV). The assessment was conducted during an 8 week training program in moderately trained runners who had performed at least one 10k race in the previous year. 29 participants (average age 37) performed a 10k run before the supervised training program and then again at the end, after a short tapering period designed to maximise performance. HRV was monitored every morning using a Polar S810 to record RR heartbeat intervals, and processed to give parasympathetic HRV as LnRMSSD (which is the same measure as ithlete uses). They also measured heart rate recovery (HRR) after a standardised 5 minute exercise every second week during the training period.
What did they find?
- Out of the 29 runners who completed the training, HRV data was only complete in 14 cases due to artifacts and HRV recording problems.
- Of these 14 with complete HRV data sets, 3 were considered ‘non-responders’ because their 10k run times did not improve after training.
- Participants with the highest starting HRV were the fastest runners, but those with lowest starting HRV showed the most improvement.
- All 11 responders showed increases in their morning HRV, and the ones with the largest gains in performance showed the biggest increases in HRV.
- An improvement of 10% in 10k run time required an average of 15% improvement in morning HRV, though two participants who achieved improvements of 15% in HRV achieved a more modest 3-4% improvement in 10k time.
- Morning HRV correlated well with HRV measured after the standardised 5 minute aerobic exercise, and (negatively) with heart rate recovery.
If the findings of this study scale up to larger numbers, and across different endurance events, the conclusion is that if your HRV improves, so will your race performance. The converse being that if your HRV baseline does not improve during training or taper, neither will your performance on the big day!
Also, don’t be disheartened if you have a modest ithlete HRV score to start with – a good training program can result in significant improvement.
Implications for HRV guided training
The implications of this study I find far reaching, and even after re-reading the paper several times I still don’t think I have got everything out of it that I would like to. The finding that only those participants whose morning HRV increased showed improved race times is similar to the findings of Chalencon et al for swimmers (summary available here), and no less striking.
The challenge is to find individualised training programs that cause autonomic adaptations to take place. For sure the ratios of times spend in different intensity zones, as well as periodisation are important. In this latter aspect, it would be interesting to see whether a training program that produces beneficial adaptations during a period of 6-8 weeks continues to do so for longer periods, and whether the pattern of daily or weekly changes in HRV could be used to predict whether a particular program needs to be refreshed to keep the body guessing and avoid saturation (as well as the negative psychological effects of training monotony).
Another interesting aspect was the use of a standardised protocol for taking HRV measurements after 5 minutes of aerobic exercise. This could (and I believe is) being used in team sports where compliance with waking measurements might be an issue, so HRV tests can be performed supervised on players shortly after they arrive at the training centre, with the opportunity still to vary the day’s program depending on the results.
Thoughts on any of these aspects very welcome, as ever!
by Simon WegerifMonitoring endurance running performance using cardiac parasympathetic function. Buchheit M, Chivot A, Parouty J, Mercier D, Al Haddad H, Laursen PB, Ahmaidi S. Eur J Appl Physiol. 2010 Apr;108(6):1153-67. doi: 10.1007/s00421-009-1317-x. Epub 2009 Dec 22. http://www.ncbi.nlm.nih.gov/pubmed/20033207