When Evgenia Koroleva started learning about her menstrual cycle and the effect it was having on her, week to week, she says: “It blew my mind. Why did I know so little about my body?” A gym owner, Koroleva has since created a training programme based around an individual’s cycle, which she says will optimise results.
Hers is not the first to take the menstrual cycle into consideration when it comes to exercise. Interest has grown hugely in recent years, with elite athletes tracking physiological changes and coaches educating themselves about the effects. For the rest of us, there are apps and cycle trackers, but the area is still woefully under-researched (blame male-dominated medicine and sport).
There are also a lot of conflicting results, while almost half of the existing studies are low quality, says Kelly Lee McNulty, a PhD student at Northumbria University, who is investigating the effects of the menstrual cycle on performance, adaptation and recovery. “While performance and training based on the menstrual cycle is such an interesting concept, and very popular at the moment, there’s not enough published high-quality evidence,” she says. (There is even less on the impact of hormonal contraception on exercise performance, so where we refer here to the menstrual cycle, it is for women who are not on the pill or using an implant.) However, there are generalities that could be helpful for some women. Here is how your cycle may be affecting your workout.
Get to know your cycle
The 28-day cycle is split into two halves – follicular and luteal, either side of ovulation. Very broadly, taking a 28-day cycle as the textbook example, McNulty defines the most-relevant phases as early follicular (days one to five), with low oestrogen and progesterone; late follicular (days six to 12), with high oestrogen and low progesterone; and mid-luteal (days 20 to 23), with high oestrogen and progesterone. “Women are so different; we experience our menstrual cycles differently and a blanket approach is not going to work for everyone,” she says. Collect your own data, she advises – there are numerous apps, but a notebook is fine – “and then look for patterns”. If one week you can blitz a high-intensity workout and the next you can barely make it through, it doesn’t mean your fitness has gone backwards. If your motivation is suffering, it doesn’t mean you are a failure. It could all simply be hormonal. “Then you’ve got hormone fluctuations daily, so it all becomes more complex,” McNulty says.
Try exercising through the symptoms
“There are more than 150 symptoms, like breast pain, headaches and nausea … potentially, that’s a time to decrease training if you’re not feeling it,” says McNulty. “But then it’s also been shown that moderate-intensity exercise, like yoga, is beneficial for premenstrual symptoms.” Around days three to five of your period, oestrogen starts to increase, “so you might be starting to feel better and up for exercise around that time”. Koroleva says: “Training on your period is a good way to offset your symptoms.”
Push yourself up to week three …
In the late follicular and the mid-luteal phases, oestrogen is higher. McNulty says one of its many effects is to help build muscle mass. “This is when we can really push female bodies,” says Koroleva. “For the first three weeks, we push you in terms of strength training and add cardio to it. Our bodies don’t have a huge amount of testosterone, but it rises during ovulation and this makes it an ideal time to really push, because of the energy levels.” This is the time when you might set your personal bests and “sail through high-intensity training”, she says. However, it is not a given. “In that mid-luteal phase, progesterone rises; that has its own physiological effects, so you might not notice that difference,” she says. “It’s just being aware of what might work for you.”
… but be wary of injury around ovulation time
There is some evidence that, when oestrogen is high, around the late follicular phase, there is an increased risk of injury, because the hormone makes ligaments and tendons more lax. For instance, an injury to the anterior cruciate ligament (in the knee) may be more likely. “It’s something to be aware of, but I would never say not to train,” says McNulty. “But if you know this phase might have certain increased injury risks, you could warm up better.”
While it might make you more prone to injury, oestrogen also provides benefits. It is thought to have a positive effect on mood, “so this might increase your motivation to train,” says McNulty. “It has neuromuscular effects as well, so it can signal to increase your ability to activate your muscles. There is evidence to suggest that our ability to recover from training is improved, as oestrogen is thought to have a protective function against muscle damage.” It also reduces the inflammatory response, so it could reduce muscle soreness. “This might mean that we recover more quickly and therefore adapt to training more readily.”
Oestrogen is also thought to reduce the amount of carbohydrate the body uses as the fuel for exercise, instead burning fat. “In theory, it might be that, when oestrogen is high, your body might use more fats for energy – but, again, there are conflicting research findings,” says McNulty. There is some evidence that the metabolism speeds up towards the end of the cycle (and this may be why you get cravings for carbs). “On any weight-loss programme, the point is to put the body into a calorie deficit,” says Koroleva. However, if you go too far, it can be counterproductive. “If you’re trying to lose weight and you’re in the second phase of your cycle, if you’re doing high-intensity training and you don’t add carbohydrates and increase your calories, your body can actually start to hold on to the weight. It’s almost counterintuitive, but, because of the hormonal changes, the calories need to increase.”
Don’t overheat in week four
In the mid-luteal phase, progesterone rises along with oestrogen. This may limit some of the effects of oestrogen, but it has its own consequences, says McNulty. “It increases your basal body temperature, so, if you’re doing an endurance sport, you might be struggling in a hot environment a little bit more in that mid-luteal phase and you might have to adopt cooling strategies.” Progesterone is also a “calming hormone”, she says. It may increase sleep, but also can affect the way the brain picks up new skills. Trying to perfect a dance routine, or change your golf technique, may be more difficult during this phase.
Take it easy
“After the third week, taper down and do more restorative exercise, such as yoga or pilates,” says Koroleva. “It’s not the time to try to beat any records or do much strength training. If you’re trying to lose weight, it’s a really good time to do long walks and low-intensity training. In a world where we’re surrounded by these super high-intensity workouts and we beat our bodies into the ground, working with your cycle is a much kinder way to look after your body.”