The Relationship Between Physical Activity, Temperature and Hot Flashes During Menopause

Sudden changes in physical activity, temperature and humidity may increase the chances of hot flashes, according to a recent survey published in Menopause, the journal of The Menopause Society.

Menopause occurs 12 months after a woman's last period. The transition period, known as perimenopause, typically starts between ages 45 and 55 and lasts about seven years, but can extend up to 14 years, according to the National Institute on Aging.

This phase involves changes in menstrual cycles, hot flashes and hormonal fluctuations. Factors like smoking, age, race and ethnicity influence its duration.

During perimenopause, changes in estrogen and progesterone levels affect energy use, body composition, bone and heart health and weight gain.

Hot flashes affect about 80% of women around menopause, yet much remains unknown about their causes, according to The Menopause Society.

These sudden heat flashes often involve increased core-to-skin heat transfer and sweating, the Society shared.

Research indicates that reduced estradiol, a hormone that can treat menopause symptoms, levels during menopause alter the hypothalamus, which controls body temperature.

While physical activity helps postmenopausal women maintain health, bone density and mental well-being while reducing osteoporosis, weight gain, stress, anxiety, and depression, it can raise body temperature and potentially trigger hot flashes.

A previous study found that women with a history of hot flashes experienced them during acute exercise, unlike asymptomatic women. Few studies, however, have used ambulatory monitoring, or heart rate and blood pressure monitoring over a period of time, to explore this effect.

The Menopause Society said in a release that recent findings suggest that increased moderate physical activity and hot temps and humidity is associated with more reported hot flashes, but results in natural settings are unclear.

To test the unknown, researchers of the Menopause study examined the impact of physical activity, temperature, and humidity on hot flashes in women aged 45 to 55 in Western Massachusetts during cooler months.

They monitored 270 women across three menopause stages for 24 hours using ambulatory monitors.

Hot flashes were tracked by skin conductance, where the skin momentarily becomes a better conductor of electricity when either external or internal stimuli occur that are physiologically arousing, and with event markers.

Physical activity was measured with wrist accelerometers. Logistic multilevel modeling analyzed differences in conditions preceding hot flashes compared to control periods without hot flashes.

Data from 188 participants showed that sudden increases in physical activity significantly raised the chances of experiencing waking hot flashes, both objective (OR 1.31) and subjective (OR 1.16).

Increased sleep signals also raised the chances for both objective (OR 1.17) and subjective (OR 1.72) sleeping hot flashes.

Higher temperatures were linked to sleeping hot flashes (OR 1.38).

No significant relationship was found between humidity and hot flashes.

Researchers concluded that increased physical activity raises the chances of hot flashes, both measured and reported, day and night. Higher temperatures only relate to reported nighttime hot flashes.

They stressed the importance of monitoring, as not all hot flashes are noticeable, particularly at night when women might not wake up due to a hot flash.

Recommended exercise practices per Kaiser Permanente Medicine for women during and after menopause include:

• Prioritize daily movement in activities such as walking, cycling, or playing outdoor games.
• Aim for three cardio sessions weekly, including jogging or elliptical training, totaling at least 150 minutes.
• Incorporate high-intensity interval training (HIIT) and strength exercises to boost metabolism, bone density, and muscle strength.
• Balance routines like yoga and Tai Chi enhance stability and prevent falls, crucial for aging women.
• Opt for low-impact activities to protect joints, favoring swimming or recumbent biking.

Coupled with a balanced diet, these practices promote overall health during menopause. Drinking enough water and getting enough fiber is also crucial according to Kaiser.