Menstrual cycle, exercising and thermoregulation in heat

Summary of a systematic review and meta-analysis on the thermoregulation during exercising in heat in relation to menstrual cycle phases.

Who

Healthy females trained and untrained.

Design

Systematic review and meta-analysis of 9 studies.

Outcome measures/tests

body temperature (rectal temperature, esophageal temperature, or both)
female hormones levels: progesteron, estrogen
physical tests: cycling, walking, running, shuttle running

menstrual cycle – a cyclic changes in woman's body allowing for pregnancy.

Menstrual cycle

Main results

no difference between luteal and follicular phase in sweat rate, mean skin temperature or exercise heart rate was observed
VO₂max and follicular phase progesteron levels did not differ
Before exercise:
- pooled effect showed 0.18°C increase in body internal temperature in luteal phase compared to follicular phase
  - higher internal body temperature in luteal phase than follicular phase (all studies, but one)
After exercise:
- pooled effect showed 0.05°C increase in body internal temperature in luteal phase compared to follicular phase
  - 4 studies reported increase in internal temperatue in luteal phase compared to follicular phase
  - 4 studies reported no difference in the heat
  - one study reported that the difference depended on the environment
increased environmental temperature led to less variation between menstrual cycle phases (luteal and follicular)

Take home message

For a clinician & coach

On average there is a difference of 0.18°C incease in body internal temperature in luteal phase compared to follicular phase. This difference is 0.05°C after the exercise. In hot conditions differences between luteal and follicular phases after exercising are less prominent.

For a parent

Body internal temperature increases in luteal phase of menstrual cycle compared to follicular phase both before and after exercise.

For an athlete

Body internal temperature increases in luteal phase of menstrual cycle compared to follicular phase both before and after exercise.

Original article

Giersch GE, Morrissey MC, Katch RK, Colburn AT, Sims ST, Stachenfeld NS, Casa DJ. Menstrual cycle and thermoregulation during exercise in the heat: A systematic review and meta-analysis. Journal of Science and Medicine in Sport. 2020 May 23.