The aim of the study is to investigate the effect of the different menstrual cycle phases on the recovery from exercise-induced muscle injury in eumenorrheic women. For this purpose, in a cross-over, randomized study, at least 10 healthy eumenorrheic women aged 18-35 years will participate. In a random order, the participants will perform 45 min downhill (-15% slope) running on a treadmill at 70% HRmax followed by a maximal time-trial (95% HRmax) to exhaustion: i) during the follicular phase and ii) during the luteal phase. Before the exercise protocol, as well as at 24 h, 48 h and 72 h following exercise, complete blood count, delayed onset of muscle soreness (DOMS), creatine kinase activity, countermovement jump, isometric, concentric and eccentric strength of knee extensors and knee flexors, will be assessed. In addition, lactic acid concentration will be assessed before and immediately following exercise, and DOMS will be assessed immediately after the end of exercise. Following a washout period of ≥28 days (depending on the length of the menstrual cycle), participants will repeat the exact same procedure for the remaining phase of the menstrual cycle.
Age range
18 Years – 40 Years
Sex
FEMALE
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A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Changes in Creatine kinase (CK) activity
Timeframe: At baseline (pre), post-, 24 hours post-, 48 hours post-, 72 hours post-trial
Changes in delayed onset of muscle soreness (DOMS)
Timeframe: At baseline (pre), post-, 24 hours post-, 48 hours post-, 72 hours post-tria
Changes in blood lactate concentration
Timeframe: At baseline (pre), 4 minutes post-exercise
Changes in countermovement jump (CMJ) height
Timeframe: At baseline (pre), 24 hours post-, 48 hours post-, 72 hours post-exercise
Changes in isokinetic strength of knee extensors (KE) and knee flexors (KF)
Timeframe: At baseline (pre), 24 hours post-, 48 hours post-, 72 hours post-exercise
Changes in complete blood count (CBC)
Timeframe: At baseline (pre), 24 hours post-, 48 hours post-, 72 hours post-exercise