Effects of a training intervention tailored to the menstrual cycle on endurance performance and hemodynamics

BACKGROUND: This study aimed to compare the effects of block periodized training and training adapted to the menstrual cycle (MC) phases on endurance performance, cardiovascular parameters, recovery, and MC-related symptoms in active females. METHODS: Fourteen naturally menstruating, moderately trained females (age: 24 +/- 3 years; BMI: 22.3 +/- 2.7) were randomized into an intervention (INT) and a control (CON) group. Throughout an 8-week intervention period, both groups participated in a polarized training program. In the INT, the training sessions were adapted to the MC with higher training loads within the mid and late follicular phase. Before and after the intervention maximal oxygen consumption (VO2max), velocity and heart rate at ventilatory thresholds one and two (vVT1, vVT2, hrVT1, hrVT2), systolic and diastolic blood pressure (sBP, dBP), root mean square of successive RR interval differences (RMSSD), standard deviation of NN intervals (SDNN), pulse wave velocity (PWV), and the premenstrual assessment form (PAF) were assessed. RESULTS: There were no significant time x group interaction effects in all physiological parameters (VO2max: P=0.890; vVT1: P=1.000; hrVT1: P=0.464; vVT2: P=0.356; hrVT2: P=0.762 sBP: P=0.948; dBP: P=0.203; RMSSD: P=0.257; SDNN: P=0.241; PWV: P=0.818), or psychological parameters (PAF: P=0.745). CONCLUSIONS: Tailoring a polarized training program to the MC did not augment training responses compared to a regular training program in active females. However, a substantial portion of the training intervention in the CON was coincidentally matched to the MC.