Study, 2020
Does body temperature and energy use change during different menstrual cycle phases?
Yes. Women's core body temperature increased by 0.27°C in the luteal phase compared to follicular phase, and energy use increased by 6.9%. Heat loss was reduced during early sleep in the luteal phase.
What they did
Researchers studied 9 young women during sleep. They measured energy use in a metabolic chamber, recorded sleep patterns, and monitored core and skin temperature continuously. Measurements were taken once in luteal phase and once in follicular phase.
What they found
In luteal phase, core body temperature was 0.27°C higher, energy use was 6.9% higher, and heat dissipation was suppressed during the first 2 hours of sleep. The temperature increase alone does not fully explain the energy increase.
What it means for you
During the luteal phase, women's bodies burn more energy and run warmer, partly from higher temperature but also from other hormone effects. This could explain why women feel different at different cycle times. The study was very small (9 women).
9
young women studied
+0.27°C
core body temperature increase in luteal phase
+6.9%
energy expenditure increase in luteal phase
About the study
- Original title
- Changes in sleeping energy metabolism and thermoregulation during menstrual cycle
- Authors
- Zhang S, Osumi H, Uchizawa A et al.
- Journal
- Physiological reports
- Year
- 2020
- Study design
- Study
- Participants
- 9
- What was tested
- None - measurement during different cycle phases
- Open access
- Yes
- Read the paper
- doi.org/10.14814/phy2.14353
Original abstract
Women with ovulatory menstrual cycles show an increase in body temperature in the luteal phase, compared with follicular phase, particularly during the night. Several, albeit not all, studies reported higher energy expenditure in the luteal phase compared with follicular phase. Q 10 of biological reactions lies between 2.0 and 3.0, predicting a 7-12% increase in energy expenditure when body temperature rises by 1°C. In this study, temperature dependence of energy expenditure was assessed by comparing changes in sleeping energy expenditure and thermoregulation with menstrual cycle in 9 young females. Energy expenditure was measured using a metabolic chamber, in which sleep was recorded polysomnographically, and core body temperature and skin temperature were continuously monitored. Distal-to-proximal skin temperature gradient was assessed as an index of heat dissipation. In the luteal phase, a significant increase in average core body temperature (+0.27°C) and energy expenditure (+6.9%) were observed. Heat dissipation was suppressed during the first 2 hr of sleep in the luteal phase, compared with follicular phase. Rise in basal body temperature in the luteal phase was accompanied by increased energy expenditure and suppressed heat dissipation. The 6.9% increase in metabolic rate would require a Q 10 of 12.4 to be attributable solely to temperature (+0.27°C), suggesting that energy expenditure in the luteal phase is enhanced through the mechanism, dependent and independent of luteal-phase rise in body temperature presumably reflects other effects of the sex hormones.
Reproduced under CC-BY.