Hot flashes may be impacted by acute changes in physical activity, temperature, and humidity, according to a recent study published in Menopause, the journal of The Menopause Society.1
Takeaways
- Acute increases in physical activity significantly raise the risk of experiencing both objective and subjective hot flashes, particularly during waking and sleeping periods.
- Higher ambient temperatures are associated with a greater likelihood of subjective hot flashes but not objective ones.
- Changes in humidity do not appear to influence the risk of hot flashes.
- The study used sternal skin conductance and wrist-worn accelerometers to objectively and subjectively monitor hot flashes and physical activity in real-world settings.
- To mitigate nighttime hot flashes, behavioral measures such as using lighter blankets and fans may be beneficial.
Approximately 80% of postmenopausal women experience hot flashes, defined as sudden heat dissipation leading to increased heat transfer and sweating. However, there is still little information about the underlying sources behind these events despite multiple related studies.
Decreasing estradiol levels during menopause transition have been linked to hot flashes, but physical activity may also play a role because of associated increased body temperature. Previously, women with a history of hot flashes have reported experiencing a hot flash following acute physical activity.
While data has indicated an increase in subjective reporting of hot flashes among menopausal women with greater amounts of physical activity than usual during the day, there is little data evaluating the impact of physical activity on hot flashes through ambulatory monitoring.
Researchers have also theorized ambient temperature and humidity may impact hot flashes. However, data in natural settings remains lacking.
Investigators conducted a study to evaluate the association between acute changes in physical activity, temperature, and humidity on hot flash experiences.2 Data was collected in Western Massachusetts between October and April.
Participants included women aged 45 to 55 years across 3 menopause stages. These patients were provided ambulatory monitors that recorded hot flashes, physical activity, temperature, and humidity across a 24-hour period.
Sternal skin conductance was used to objectively record hot flashes, while subjective measuring was obtained through an event marker and data logging. Wrist-worn accelerators were also utilized for physical activity monitoring and recording of sleep and wake periods.
Differences in physical activity, temperature, and humidity in the 10 minutes before a hot flash were calculated using logistic multilevel modeling and compared to a control window when no hot flash occurred. The odds for objective and subjective hot flashes and for wake and sleep periods were recorded separately.
There were 188 participants included in the final analysis. A significant association was found between acute increases in physical activity and increased risk of objective waking hot flashes, with an odds ratio (OR) of 1.31. For subjective waking hot flashes, the OR was 1.16.
Similarly, the risks of objective and subjective sleeping hot flashes rose from increased actigraphy signal, with ORs of 1.17 and 1.72, respectively. Additionally, an increase in temperature had an OR of 1.38 for subjective hot flashes, indicating a significant association.
Increased temperature was not associated with an increased risk of objective hot flashes. Additionally, no association was reported between humidity and hot flash risk.
Overall, only acute increases in physical activity were associated with increased risk of both objective and subjective hot flashes. Investigators noted that restlessness and increased microclimate temperature at night may lead to hot flashes, indicating behavior measures such as lighter blankets and fans may be beneficial.1
“This study shows a link between increases in physical activity and subsequent subjective and objective hot flashes during both waking and sleeping periods,” said Stephanie Faubion, MD, MBA, medical director for The Menopause Society. “Clinicians may advise patients of this link while acknowledging the multiple well-known benefits of physical activity.”
References
- Too much exercise could actually trigger a hot flash. The Menopause Society. May 29, 2024. Accessed May 31, 2024. https://www.menopause.org/docs/default-source/press-release/physical-activity-and-hot-flashes.pdf
- Witkowski S, White Q, Shreyer S, et al. Acute increases in physical activity and temperature are associated with hot flash experience in midlife women. Menopause. 2024. doi:10.1097/GME.0000000000002373
