Predicting and monitoring individual endurance training adaptation and individualizing training prescription : with endurance performance, cardiac autonomic regulation and neuromuscular performance

Humans adapt differently to standardized endurance training programs. While some individuals may achieve huge improvements in physical fitness, other individuals may even suffer from negative adaptations. Special attention should be paid to identification of non-responders, which would enable to modify training to be more effective. Therefore, the aim of the present study was to investigate whether running performance, cardiac autonomic regulation and neuromuscular performance can be used in 1) predicting subsequent endurance training adaptations; 2) monitoring training adaptations; and 3) individualizing training prescription in recreational endurance runners. Three longitudinal training studies were performed consisting of: 1) a 28-wk period with progressively increasing training volume and intensity (n = 28); 2) an 18-wk period including either a high volume of low-intensity (HVT) or high-intensity training (HIT) (n = 40); and 3) a 12-wk study with heart rate variability (HRV) guided training (n = 40). Nocturnal HRV was the strongest pretraining subject characteristic to predict training adaptation being negatively associated with the adaptation to HVT and positively to HIT. Thus, runners with lower HRV showed greater positive changes in endurance performance after HVT, while runners with higher HRV responded well to HIT. Running speeds of 80-90% of HRmax in a three-stage warm-up running protocol were the most competent variables to monitor changes in maximal endurance performance during the training period. In the final study, the HRV-guided group trained according to daily HRV measures. HIT was completed, if HRV was within a normal range. Otherwise, low-intensity training was performed. Endurance and neuromuscular performances improved in the HRV-guided group but not in the traditional predefined training group. The findings of the thesis suggest that resting HRV and the warm-up running protocol show great potential as practical tools for monitoring of adaptations and individualizing training by selecting the content of training and for prescribing the timing of HIT sessions.