Cycle-Syncing Workouts: Popular But Lacking Scientific Support

On social media, the advice arrives with the certainty of a color-coded grid. During menstruation, the videos say, stick to steady jogging, Pilates, barre, walking—keep it gentle. As you move into your follicular phase, gradually turn up the intensity. Around ovulation, go hard with strength training and high-intensity work. Then ease back down during the luteal phase, the two weeks between ovulation and your next period. This approach, known as cycle-syncing, has exploded online. Google searches for the term have climbed 740 percent since 2022. More than 55,000 TikTok videos now carry the #cyclesyncing hashtag. The creators sharing this advice are mostly fitness and wellness influencers, not researchers or doctors.

But when scientists look at the evidence behind these recommendations, they find very little there. Kelly McNulty, a researcher at Leeds Beckett University who studies menstrual cycles and exercise, tells the BBC plainly: these videos are "a trend based on marketing rather than any kind of research or evidence." She acknowledges that some women do experience shifts in energy, symptoms, or perceived strength as their cycle progresses. That's real. What isn't supported by research is the leap from that observation to a universal prescription—the idea that all women should train a particular way at a particular time.

The core problem is individuality. Menstrual cycles vary dramatically from person to person. They can also shift within the same person from one month to the next. A cycle that runs 21 days one month might stretch to 35 the next. Many of the apps and programs promoting cycle-syncing are built around the assumption of a regular 21-to-35-day cycle, which means they offer little help to anyone with irregular periods or anyone using hormonal contraception. McNulty puts it this way: "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."

Some people who track their cycles do notice patterns worth paying attention to. Cesci Burgoyne, a nurse, personal trainer, and nutritionist based in Sydney, adjusts her training based on how she feels—easing off during her luteal phase, pushing harder during her follicular phase when she feels energized. But she doesn't follow a rigid plan. Sarah Mackay, a fitness creator with a large following on Instagram and TikTok, has observed real changes in her energy, motivation, cramps, and mood throughout the month. Yet she deliberately avoids strict prescriptions because, she says, "there are too many variables at play." She has even hit personal records while menstruating, contradicting the common advice to avoid intense training during that time.

Dr. Faye Bate, a medical doctor specializing in women's health, worries about a different risk: the nocebo effect. When women are repeatedly told they will be weaker or less capable at certain points in their cycle, that negative expectation can itself influence how they feel and perform. There's also a practical concern about strength. Women face a higher risk of osteoporosis later in life, and building bone density requires consistent, progressively challenging resistance training. If cycle-syncing advice leads women to ease off strength work for half the month, McNulty warns, "we don't want to create another barrier by suggesting women train less for almost half the month." Bate also cautions against normalizing severe symptoms. If pain, fatigue, or mood changes genuinely interfere with daily life or exercise, that's a sign to seek medical advice, not to accept it as inevitable.

What the experts do support is what they call being "cycle-aware." Tracking your cycle can reveal your own patterns. Understanding how you feel at different points in the month is valuable information. That might mean having painkillers ready before your period, taking a rest day when symptoms are worse, or scaling back a workout if you feel unusually tired. The shift is subtle but important: use your cycle as data about yourself, not as a rulebook handed down from social media. As Bate says, "the most important part is tuning in to how you feel." The conversation around menstrual health is healthier now than it was—more open, less taboo. But the conversation should center on what your body actually tells you, not on what a color-coded grid predicts.