Why some women are 'cycle-syncing' their workouts

Sarah Mackay, known as @fitwsarah online, says her energy levels change through her cycle

A woman points to a colour-coded grid dividing the menstrual cycle into four phases, each paired with a different list of exercises.

This is one of thousands of videos on TikTok and Instagram suggesting that people change their workouts depending on where they are in their menstrual cycles - something known as 'cycle-syncing'.

Most of the advice is shared by fitness and wellness creators rather than medical or research experts.

gradually increasing intensity in the follicular phase leading up to ovulation

easing off again during the luteal phase (between ovulation and the start of your period)

Kelly McNulty, a researcher at Leeds Beckett University specialising in menstrual cycles and exercise, says there is evidence that some women experience changes in symptoms, energy or perceived strength across their cycle.

"There isn't any research to support that kind of phase-based prescription," she says.

A key issue is that menstrual cycles are highly individual, McNulty adds - they can differ between women, and one woman's experience can also change from one cycle to the next.

Many cycle-tracking apps and programmes are also designed around relatively regular menstrual cycles that are 21 to 35 days, which can make their recommendations less applicable to people with irregular periods, or those using hormonal contraception.

There are now thousands of videos on Instagram and TikTok recommending women sync their workouts to their menstrual cycles

Cesci Burgoyne, a nurse based in Sydney, Australia who is also a qualified personal trainer and nutritionist, adjusts her training depending on how she feels in her cycle. She doesn't follow a prescriptive plan, she says, but instead makes changes intuitively.