Despite being exposed to the same standardized training program; inter-individual responses will vary considerably among athletes. The training load will be too much for some, too little for others and just right for a few. Therefore, it’s important for coaches to appreciate the need for evaluating the individual responses to training. Knowing and quantifying training load is only half the battle. Training responses can be evaluated with both objective measures (such as physiological metrics) as well as subjective measures (such as wellness questionnaires). A physiological parameter gaining interest among coaches is heart rate variability (HRV). HRV reflects central regulation of the heart and is used as a non-invasive marker of stress. Some evidence suggests that monitoring HRV throughout training may be useful for assessing how athletes are coping with training.
A new study published ahead of print in the Journal of Science and Medicine in Sports observed how HRV and wellness parameters (i.e., perceived sleep quality, muscle soreness, fatigue, mood and stress) responded to overload and tapering in collegiate swimmers. Ten NCAAA Division-1 sprint-swimmers recorded HRV and completed the wellness questionnaires daily after waking using a novel smartphone application and pulse-wave finger sensor. HRV and wellness parameters were averaged across 1 week of baseline followed by 2 weeks of overload training and two weeks of tapering leading up to a championships competition. The overload period was characterized by a substantial increase in anaerobic workload while total volume varied by only 20%.
The results showed that compared with baseline, HRV significantly decreased and demonstrated significantly greater fluctuation during the overload. During the taper, HRV returned to baseline or peaked leading into competition where subjects significantly improved their race times. Of the wellness parameters, muscle soreness and fatigue demonstrated a similar inverse bell-shaped trend in response to competition preparation. Sleep quality was significantly improved during the taper. It appears that HRV and wellness questionnaires demonstrate sensitivity to changes in training phase. Therefore, these parameters may be useful for coaches to monitor individual responses to training.
Flatt Andrew A, Hornikel Bjoern, Esco Michael R. Heart rate variability and psychometric responses to overload and tapering in collegiate sprint-swimmers. Journal of Science and Medicine in Sport http://dx.doi.org/10.1016/j.jsams.2016.10.017