Rate of Heart Rate Increase

Monitoring resting heart rate and heart rate variability are valuable markers of training adaptation. While convenient, recent research has suggested these parameters may not be adequately sensitive to both post-exertional fatigue decreases in performance and training-induced improvements in performance (Buchheit, 2014; Bellenger CR, et al. 2016) possibly due to various methodological inadequacies and/or inconsistencies. 

The maximal rate of heart rate increase (rHRI) is a marker of heart rate acceleration during the transition from rest to submaximal exercise which correlates with both fatigue-induced decrements in performance and training-induced improvements in performance. More precisely, assessing rHRI to 8km/hr over two to four minutes has been found to be optimal in assessing training induced changes in performance in a 5km time trial (Nelson et al., 2020). rHRI is also linearly related to anaerobic performance and therefore may also be used to assess how power athletes are responding to training loads (Noah et al., 2022). A slower acceleration may indicate fatigue or lesser conditioning whereas a greater acceleration may indicate improved fitness and greater capacity for work. Adapting ones training according to our bodies indicators is both a smart and effective way to avert overreaching and maximize performance outcomes. Gather the data and heed the signals!