HRV predicts race performances: Case Study

The terms “preparedness” and “readiness” are two major buzzwords in the strength and conditioning world these days. “Preparedness” refers to the physical fitness of the athletes, relative to the specific demands of their sport. This may involve having a high VO2max for endurance athletes or soccer players, high intermittent running capacity for rugby and basketball players, and so forth.

“Readiness” on the other hand, pertains to the daily fluctuation in an athlete’s abilities to fully express their skills and fitness (including strength and power). Think about when you are lifting heavy triple’s in the weight room. Some day’s the weight feels heavy and some day’s it feels light. Likewise when you go out for a run, some days it feels easy and some days it feels harder. These fluctuations in performance occur despite any real changes in absolute strength or fitness. “Readiness” is the term used to describe the current state of an athlete as it pertains to performance potential.

Monitoring an athlete’s readiness is difficult, and likely varies based on sport. Some use a power test like a vertical jump, or a reactive test like a drop-jump. A popular metric used by some is heart rate variability, which is a non-invasive method for cardiac-autonomic nervous system assessment. Generally speaking, when HRV is at or above baseline, it is thought that an athlete is in a more adaptable and recovered state. Alternatively, when HRV is below baseline, it is thought that the athlete may not be fully recovered or may be experiencing fatigue.

In a recent case study published in the Journal of Australian Strength and Conditioning, HRV almost perfectly predicted weekly 8 km running performance in a collegiate cross-country athlete. HRV was assessed daily, by the athlete with a smart-phone application. The weekly mean and coefficient of variation (CV) was calculated for each week. The CV correlated near perfectly (r = 0.92) with weekly race times.

The CV reflects the variance in a metric, expressed as a percentage (CV = [SD/mean]*100). So the weeks where HRV displayed greater changes on a day to day basis, performance was worse and vice versa. Even when running the same race course on the same day several weeks apart, the CV was the best predictor of performance. On week 3 and week 8 the athlete raced at the same course, however in week 8 the athlete ran over a minute faster than in week 3. HRV mean values were not different, however the CV was half of what it was in week 3. Therefore, at least for short distance endurance events such as 8 km races, the CV of HRV may be a useful readiness marker.

 

Flatt, AA, and Esco, MR. Endurance performance relates to resting heart rate and its variability: A case study of a collegiate male cross-country athlete. J Austral Strength Cond, 22:48-52, 2014.