Influence of the Menstrual Cycle on Muscle Glycogen Repletion After Exhaustive Exercise in Eumenorrheic Women

Abstract

Influence of the menstrual cycle on muscle glycogen repletion after exhaustive exercise in eumenorrheic women. J Strength Cond Res 37(4): e273-e279, 2023-The purpose of this study was to investigate the effect of the menstrual cycle on muscle glycogen repletion postexercise. Eleven women with regular menstrual cycles (age: 20.2 6 1.3 years, height: 161.1 6 4.8 cm, and body mass: 55.5 6 5.7 kg) were assessed in 3 phases of the cycle: the early follicular phase (E-FP), late follicular phase (L-FP), and luteal phase (LP). Each test day began with glycogen-depleting exercise, followed by 5 hours of recovery. Muscle glycogen concentrations, using 13 C-magnetic resonance spectroscopy, and estradiol, progesterone, blood glucose, blood lactate, free fatty acid (FFA), and insulin concentrations were measured at t 5 0, 120, and 300 minutes postexercise. During the 5-hour recovery period, subjects consumed 1.2g•(kg body mass) 21 •h 21 of carbohydrates every 30 minutes. The muscle glycogen concentrations increased at t 5 120 and t 5 300 minutes postexercise (p , 0.01) but were not significantly different between the menstrual cycle phases (p 5 0.30). Blood lactate concentrations were significantly higher in the L-FP and LP than in the E-FP (p , 0.05). Nonetheless, the blood glucose, FFA, insulin concentrations, and the exercise time until exhaustion in the E-FP, L-FP, and LP were similar (blood glucose, p 5 0.17; FFA, p 5 0.50; insulin, p 5 0.31; exercise time, p 5 0.67). In conclusion, the menstrual cycle did not influence muscle glycogen repletion after exercise.

Type 1 Diabetes and the Menstrual Cycle: Where/How Does Exercise Fit in?

“…Estrogen levels and muscle glycogen use were found to be positively correlated, suggesting that estrogen increased reliance on glycogen at high intensities [54]. As for muscle glycogen repletion, however, it seems that there may not be a significant difference between menstrual cycle phases after exhaustive glycogen-depleting exercise in eumenorrheic women [55].…”

Methodology for studying Relative Energy Deficiency in Sport (REDs): a narrative review by a subgroup of the International Olympic Committee (IOC) consensus on REDs

“…Reduced skeletal muscle function: LEA-related and REDs-related skeletal muscle outcomes include changes to substrate oxidation, intramuscular fuel stores and protein metabolism status. Substrate oxidation can be assessed both indirectly (expired whole-body gas analyses) and directly (tracers) [118][119][120] at rest or during the exercise of varying intensities, durations and modes. Oxidation rates, however, will be affected by preceding feeding status (fasted vs fed, meal composition) and must be controlled.…”