Responsiveness of Time and Cost-Efficient Monitoring Measures on Triathlon Training a Call for Individualized Training Monitoring

Objective: We aimed to assess the responsiveness of monitoring measures on cumulative training from the previous 1 up to 7 days in elite triathletes.

Methods: Six male well-trained triathletes (31.8 ± 6.8 yrs, VO2max 70.5 ± 4.0 ml/kg/min) participated in a 9 weeks observational study during the pre-competition training period. Training load and time spent in different training intensity zones, morning measures of objective monitoring variables including resting heart rate, heart rate variability (HRV) and sleep duration and subjective monitoring variables including subjectively felt daily condition, energy level, willingness to train, muscle soreness, general stress, general fatigue and quality of sleep were assessed daily. Training data were retrospectively correlated with objective and subjective measures

Results: On a group level, higher cumulative training time spent in high-intensity running but not swimming or cycling lead to moderate increase in muscle soreness (R=0.344 for 5-days cumulative high-intensity running, p=0.043), small increase in subjectively felt general stress (R=0.168 for 4-days.

Cumulative high-intensity training time (cHITT), p=0.043 and R=0.221 for 6-days cHITT, p=0.043), a small decrease in daily condition (R=-0.113 for 7-days cHIIT, p=0.043) and willingness to train (R=-0.169 for 7-days cHIIT, p=0.043) but did not affect any objective monitoring variables.There were remarkable individual differences in correlations between cumulative training load, time spent in different training intensity zones and objective and subjective variables

Conclusion: Since the responsiveness of objective and subjective monitoring parameters to training was very individual, not only training loads but also the selection of objective and subjective measures should be individualized for monitoring triathletes.