The effects of progressively increased training load and
overtraining on resting and intrinsic heart rate and cardiac autonomic
modulation, and their relationships to performance variables were investigated in female athletes (runners, triathletes, cross-country skiers, orienteers). A control group of athletes (N=6) and
experimental group of athletes (N = 9) served as Ss. The athletes increased training volume of intensity 70-90% VO2max by 130% and training volume at <70% VO2max by 100% during 6-9 weeks. At the same time, the controls increased training volumes by 5 and 10% respectively.
Over the training period, the neither group exhibited any changes in VO2max, intrinsic heart rate, or sympathovagal balance index. Resting heart rate tended to decrease in the experimental group and increase in the control group. Five experimental athletes exhibited
overtraining symptoms with a significant decrease in VO2max but no change in heart rate, intrinsic heart rate or sympathovagal balance index.
Implication. Heart rate is not related to overtraining in female runners