Experts question science behind cycle-syncing workouts
Health and fitness experts caution that popular social media advice to tailor exercise to menstrual cycle phases lacks strong scientific backing and may
Online searches for 'cycle-syncing' workouts have surged 740% since 2022. More than 55,000 TikTok videos use the related hashtag, promoting plans that divide the menstrual cycle into phases for specific exercises.
Most advice comes from fitness creators, not medical experts. They typically recommend gentle exercise during menstruation, building intensity in the follicular phase before ovulation, hard training around ovulation, and easing off in the luteal phase before the next period.
A trend based on marketing
Kelly McNulty, a researcher at Leeds Beckett University, tells reporters there is evidence some women experience symptom changes across their cycle. However, she says the phase-based exercise prescriptions found online are "a trend based on marketing rather than any kind of research or evidence."
McNulty states a key issue is individuality. Cycles differ between women and can change from month to month. This makes blanket social media advice difficult to apply. Many apps and programmes are designed for regular 21 to 35-day cycles, which may not suit those with irregular periods or using hormonal contraception.
"It's not so much about doing certain exercises in certain phases, it's about working with your own individual body and what your needs might be," she says.
Intuitive changes rather than strict plans
Cesci Burgoyne, a nurse and personal trainer in Sydney, adjusts her training intuitively based on how she feels. "In my luteal phase I'll try and ease off in the training," she tells reporters. "In my follicular phase, I'm so energised, I feel like I can lift so much heavier."
Burgoyne welcomes more discussion of women's health, noting historical research focused heavily on male bodies. Fitness creator Sarah Mackay also notices her energy and mood change monthly but avoids strict plans. She says she has sometimes hit personal records while menstruating, contrary to advice to avoid intense training during a period.
"The problem is not that the menstrual cycle is irrelevant," Mackay says, but that "not everything is predictable."
The 'nocebo' effect and risks
Dr Faye Bate, a women's health expert, is wary of one-size-fits-all phase-based advice. She is concerned that repeatedly telling women they are weaker at certain points could create a 'nocebo' effect, where negative expectations harm performance.
McNulty warns that routinely easing off resistance training for nearly half the month could limit strength gains. This is particularly important for women, who face a higher risk of osteoporosis later in life. Building strength requires consistent, challenging training.
Dr Bate also cautions against normalising severe symptoms. If pain, fatigue, or mood changes interfere with daily life, women should seek medical advice rather than assuming it's an inevitable part of their cycle.
How to be 'cycle-aware'
While cycle-syncing lacks strong evidence, experts suggest being 'cycle-aware.' McNulty says tracking your cycle can help understand personal patterns. Dr Bate encourages women to become more familiar with their monthly experiences.
In practice, this might mean preparing painkillers before your period, taking a rest day when symptoms are bad, or easing off a workout if unusually fatigued. For Dr Bate, "the most important part is tuning in to how you feel." The consensus is to use your cycle as information, not a rigid set of rules.
