While going through menopause, many women who gain weight head to the gym for intense workouts, but new research suggests that too much exercise may help trigger another side effect: hot flashes.

In a report published May 29 in the journal Menopause, investigators found that working out too vigorously may raise the risk hot flashes.

By how much? Sharp increases in physical activity raised the chances of both objective and subjective hot flashes by 31% and 33%, respectively.

"This study shows a link between increases in physical activity and subsequent subjective and objective hot flashes during both waking and sleeping periods," Dr. Stephanie Faubion, medical director for the Menopause Society, said in a journal news release. "Clinicians may advise patients of this link while acknowledging the multiple well-known benefits of physical activity."

Meanwhile, temperature was only a contributing factor to subjective hot flashes while sleeping, raising the risk of them by 38%.

"Because temperature during sleep affected the odds of having a hot flash, modifications such as the use of lighter-weight blankets and sleepwear, as well as keeping the room temperature cooler, may help with nighttime hot flashes," Faubion added.

Hot flashes are one of the most frequently experienced menopause symptoms, with 80% of women experiencing them, researchers said. Previous studies have shown that a drop in estrogen levels triggers changes in the hypothalamus that control body temperature.

While exercise has many benefits for health and wellness, it can also increase body temperature and has been suspected as a culprit behind hot flashes.

More recent research has shown that performing more physical activity than usual in a day was related to more reports of hot flashes. However, the researchers stressed it was equally important to objectively evaluate hot flashes with physical monitoring because not all hot flashes are noticeable, especially at night when women may not wake up during a hot flash.

The latest study, led by Sarah Witkowski, from the Departmentof Exercise and Sports Medicine at Smith College in Massachusetts, involved nearly 200 participants across the three menopause stages (pre-menopause, perimenopause and post-menopause).

What did they find? There are significantly higher odds of spikes in physical activity preceding both objective and subjective hot flashes during both waking and sleeping periods.

"These data support the premise that, at least during the non-summer months, physical activity and warmer ambient temperature during sleep are associated with hot flashes," the researchers wrote. "These results can be used to inform patients that acute increases in physical activity during the day may be followed by hot flashes; however, physical activity has numerous benefits to health, and women should not be discouraged from physical movement at midlife."