training female athletes PMS menstrual cycle sports fitness

Alice Hector Pro Triathlete and Emma Risbey Public Health Nutritionist/Sports Nutritionist talk to us about how the menstrual cycle can affect female athletes and how best to deal with it.

Alice: “The monthly cycle is something that has affected me more noticeably as I get older (I’m 36). For a few days every single month I definitely see a shift in my mood and a decline in my performance. Should a race or a big training session clash around the two days of the month, or Day 1 of the glorious event itself, it's almost impossible to hit targets. My core is inflamed, rendering it useless and sloppy for running, and cramps make hard training more of a burden than ever. I gain weight in water retention and can’t stop craving chocolate (an issue most of the time, but that’s another story!)

The contraceptive pill is a no go for me as the artificial hormones really mess with me so best thing I’ve found is to avoid hard days around that date, and recognise I'll be a bit grumpy for 2-3 days before that too. However, avoidance of the hard stuff is all very well and good, but not being regular to the button makes planning, particularly racing, very difficult, and you can’t control the organisers’ race dates.”

Emma: “Everyone worries about having their period for a big event, but in reality your hormones are favourable for performance once your period starts. So whether you’re working out, training or racing, it will feel easier when you are in the low-hormone phase of your cycle which starts the first day of menstrual bleeding. Though there are very few specific studies on performance throughout the menstrual cycle, the research supports that women perform worse during the pre-menstrual phase (the luteal phase) and much better in the 1-12 days following the first day of their cycle (the follicular phase).

Alice: “Personally, I find Day 1 of my period is when the cramps and bloating are at their worst, so whilst my hormones settle immediately (mood change and better sleep), it takes a day or two for my body to feel good again. As for the science, it’s good to know that the day doesn’t have to be a write off if I prepare for it as best I can in the days preceding.”

Emma: “Absolutely, it does not mean you are doomed if a key event lands on a high-hormone or sub-par day. Research shows that key performance indicators such as VO2 max and lactate threshold remain constant throughout your cycle, so you can still aim for a PB even with PMS in endurance sports. However, if you are doing sports that involve reaction time, neuro-muscular coordination and manual dexterity – such as ball sports – during the premenstrual phase, it will be harder and more important to keep your head in the game. There’s also evidence that blood sugar levels, breathing rates and thermo-regulation are negatively impacted during this time of the month, which may well account for the slight decreases in aerobic capacity and strength too. For triathletes with heavy periods, racing in the heat and fuelling strategy is something to consider carefully when competing in this phase.

In general, exercise can feel harder during those high-hormone days before your period and there’s no doubt that it can mess with your performance. But as we know, not every period is the same and some months it may affect you less than others. So it’s important not to get in a negative head space as stress can also affect the severity of your symptoms!

Alice: “So, what are the measures we can take to try and help ourselves?”

Emma: “Planning is your first port of call. If you have a regular cycle, you can try to avoid planning your big races or events around these premenstrual dates. On days 1-3 premenstrual this is typically where you can feel and perform a little sub-par and also carry a little water retention. By taking control of your nutrition in the week before you can still perform well, but perhaps nothing spectacular.

The best time to race or compete in a big event during your cycle is 12-14 days after the first day of your period (the first day of your period is Day 1 of your cycle.) This is where oestrogen reaches a peak just before ovulation. Around ovulation your pain threshold will be higher, energy levels better, utilisation of carbohydrate (CHO) better, recovery enhanced and you generally feel happier and in a good mood. Adaptation to all types of training in this phase are generally good. Ovulation typically happens on Day 13 of your cycle. 

On days 1-14 of your cycle (the follicular phase), CHO is the primary fuel source during high intensity exercise and your body uses CHO as its main fuel source for all types of activity. But towards the end of this phase there is an increased emphasis on fats for moderate and low intensity exercise. During this phase for soft tissue recovery, include sources of collagen such as jelly alongside vitamin C rich foods to help with muscle, tendon and ligament recovery.

On days 14-28 of your cycle (the luteal phase), particularly for moderate and low intensity exercise, your body is now using fats as its main fuel source during training. During this phase, muscle breakdown may be increased, so focus on recovery after an intense workout: refuel with a protein-rich meal or snack within 30 minutes. Towards the end of this phase, your body will switch from using fats to using CHO as its main fuel source during training. This is the most common time to experience cravings and PMS. The good news is that adjusting your nutrition can help reduce these symptoms. Proteins and slow release CHO will help to maintain blood sugar levels and help reduce cravings. To reduce PMS, include foods rich in vitamin D, calcium, fish oils and magnesium. Avoid too many foods high in saturated fat as these may be associated with worsened PMS symptoms. Your sleep may be disrupted during this phase so try to include foods containing sleep-inducing melatonin such as tart cherry juice.

Energy dips are quite typical in the PMS days and it is recommended to take on board a little extra CHO before and during workouts longer than 90 minutes along with small increases in protein too. It is important to note that you burn slightly more calories overall during the premenstrual phase, so adding in a 200-250 calorie healthy snack during this period is recommended, such as some oatcakes with nut butter.

Just before your period, your hormones drop to their lowest levels. This triggers inflammation which can cause some PMS symptoms. The anti-inflammatory and immune-boosting powers of ginger can help.

A ‘food first’ approach is best so try loading up on antioxidants through your diet, including plenty of berries and green leafy vegetables (aim for 7-8 servings per day).

Alice: “A couple of my races have been a write-off, partly due to the time of the month. With Emma’s help, we created a plan to start the week before I’m due, which helps alleviate symptoms and allows me a chance of racing to a decent standard. It’s tried and tested. So here’s my PMS Checklist:

  • Ginger: raw, capsules or powder
  • Rich-coloured fruit and veg (8 portions a day)
  • Magnesium, Vitamin D, Zinc (can get from food but I take supplements) 
  • BCAAs (Amino acids) 
  • Baby Aspirin
  • Tart Cherry Juice
  • Fish and Flaxseed Oil

Key Takeaway Facts

  • Day 1-14 of your cycle is the follicular phase when you will feel and perform at your best. However this phase includes the days on your period so you may also experience bloating and water retention while you're bleeding.
  • Day 15-28 is the luteal phase which is the less favourable phase when you may experience reduced endurance, cravings, disturbed sleep, and a higher body temperature.
  • Day 1 of your cycle is the first day of your period
  • Ovulation occurs around Day 13 and is when you will have higher energy levels, improved mood, and an increased recovery ability. This is the best time to plan a race or event. 
  • Every woman is different and experiences different symptoms so it's important not to get too hooked up on what you may or may not experience in the different phases of your cycle.