When it comes to exercise and nutrition tips, there are copious amounts of scientific papers and research available. However, most of them are based on decades of research that has been focussed solely on male athletes, and neglects to take into account the differences between male and female athletes, mainly the menstrual cycle.
Fortunately, in more recent years, the scope of research has broadened and there is far more scientific literature available for female athletes and how they can optimise athletic performance around the menstrual cycle’s phases.
This blog post will explain the different phases of the menstrual cycle, how they impact what you should be doing with your training and nutrition, and optimising recovery.
An important part of this is also tracking your period and understanding that you are an N=1 study and you as the individual is what matters.
These are suggestions and recommendations based on scientific literature, but everyone is different and it’s important to take the time to find out what works for you.
What are the different phases of the menstrual cycle?
This is where the menstrual cycle starts, also known as the period. It lasts for 3-7 days and is often accompanied by cramps and low energy levels which can affect performance. Given that the body is shedding tissue and bleeding at this point, protein intake and protein synthesis are incredibly important. So protein and carbs after exercise are essential. Additionally there is greater inflammation in the body so it is advisable to increase levels of anti-oxidant and anti-inflammatory rich foods such as fruits and veg as well as Omega 3 to assist in recovery.
This is the first full phase of the menstrual cycle and includes menstruation and finishes with ovulation, it generally lasts for 13-14 days. It is characterised by lower levels of oestrogen and progesterone which can affect performance slightly (McNulty et al., 2020). Carbohydrate oxidation during exercise is higher during this phase and glycogen storage is impaired, so exogenous carbohydrate consumption is vital (Ashley et al., 2000). Practical recommendations for nutrition here are to increase carbohydrate consumption during training to ~60g/hr, consuming a gel during a 45 minute intense session, or fueling lower intensities over 60 minutes can be beneficial. As for recovery, it may be beneficial to go for a 4:1 ratio of carbs to protein rather than the usually recommended 3:1.
This is the shortest menstrual cycle phase and only lasts generally between 16-32 hours. It marks the turn point from the follicular phase to the luteal phase. However, the hormonal impacts of this phase can last for several days while oestrogen levels are at their highest. RPE during efforts is often lower during this phase and exercise performance can be higher.
This is the final phase of the menstrual cycle and starts with ovulation and ends when the period starts. The main characteristic of this phase are progesterone is at its highest while oestrogen is also higher than during most of the follicular phase. During this phase the body starts to oxidise fats at a higher ratio and muscle glycogen storage is improved (Zderic et al., 2001). Essentially, fewer carbohydrates are needed during training and for recovery.
There is also an increased breakdown of protein as well as increase in metabolic rate, so it is still important to consume enough energy overall so as to avoid low energy availability. Practically, exogenous carbohydrates are not quite as essential (but still need to be consumed) so dropping them to 40g/hr will likely still provide enough carbohydrates for most training.
Additionally, more healthy fats should be consumed to reach energy requirements as well as more protein, 25-35g post exercise. A 2:1 ratio of carbs to protein may be best for recovery.
This is the point where periods stop and there are several large hormonal changes in the body. Mainly, oestrogen levels are far lower, while muscle catabolism increases and greater reduction in bone mineral density occurs. The biggest change nutritionally here is the requirement for greater protein intake including during exercise.
The main practical recommendations here are protein intake, overall 2.2-2.4g/kg FFM (fat free mass) as well as 40-45g protein after training sessions with regular intake during the day. Branched chain amino acids (BCAAs) are beneficial to take during exercise.
How do you train according to your menstrual cycle?
Although there are practical recommendations in the scientific literature, a common trend that is always worth considering is that everyone is an individual. There are many female athletes who feel that they perform best around ovulation, and also those who feel best performance is achieved during menstruation. That being said, the general guidelines are that the early Follicular phase and late Luteal phase are often the times when performance can be impaired (Carmichael et al., 2021).
Focusing on fast movements in the gym such as plyometrics and sprint work on the bike are potentially ideal during the late Luteal phase when metabolism increases as does basal temperature. And key training sessions or races are often best done while inflammation levels are lower (outside of menstruation) and when testosterone levels are higher (ovulatory phase).
Setting the tougher sessions around when you feel best as an individual is key. If you feel best during the early follicular phase, do key sessions then.
If you feel best during the late Luteal phase, do them then. If you feel lethargic around the Ovulatory phase, reduce training intensity and duration, perhaps focus on lower intensity sub-Lactate Threshold 1 riding. Tracking your period along with training data and RPE/perceptions can give you a clearer picture and help identify trends and patterns, and if you feel comfortable doing so, talk with your coach about this.
When in your cycle are you strongest?
This we have partially answered in the previous response. However, diving into the scientific readings, when oestrogen levels are at their highest are when strength is often at its highest. This is because oestrogen has a neuroexcitatory effect, essentially this increases force production via improved neuromuscular function. However, progesterone has a cortical excitability inhibitory effect, meaning that strength and power production is impaired.
This is why often, the Late Follicular phase and Ovulatory phase are when you should be at your strongest.
Is it better to rest or workout on your period?
This is again very individual. Given that the inflammatory response is often higher during this phase, it can mean that recovery is impaired both during sessions and between them. It may be that lower intensity exercise, even at a higher volume, is still fine during your period.
Another element is rate of perceived exertion (RPE). If you get painful cramps during your period that is likely going to impact your performance during workouts. It is all very individual though, and highlights why tracking your period is vital. Not only does it help you quantifiably gauge your performance, but also helps you work out when your period should be occurring so you can adjust your training schedule around that if necessary.
How to train around your menstrual cycle: To summarise
Firstly, the effects of the menstrual cycle on both nutrition and training are variable from person to person. This is why it can be very helpful to track your period and get an understanding of when you feel best able to perform during your cycle.
The literature around training and nutrition with the menstrual cycle can be useful, but they are just guidelines. However a good rule of thumb is to prioritise strength work during the later follicular and ovulatory phases, optimal performance can often happen around ovulation, carbs should be increased during the follicular phase, energy intake and protein should be greater during the follicular phase, and more protein should be consumed for post-menopausal athletes.
McNulty, K. L., Elliott-Sale, K. J., Dolan, E., Swinton, P. A., Ansdell, P., Goodall, S., ... & Hicks, K. M. (2020). The effects of menstrual cycle phase on exercise performance in eumenorrheic women: a systematic review and meta-analysis. Sports Medicine, 50, 1813-1827.
Ashley, C. D., Bishop, P., Smith, J. F., Reneau, P., & Perkins, C. (2000). Menstrual Phase Effects on Fat and Carbohydrate Oxidation During Prolonged Exercise in Active Females. Journal of Exercise Physiology Online, 3(4).
Zderic, T. W., Coggan, A. R., & Ruby, B. C. (2001). Glucose kinetics and substrate oxidation during exercise in the follicular and luteal phases. Journal of applied physiology, 90(2), 447-453.
Carmichael, M. A., Thomson, R. L., Moran, L. J., & Wycherley, T. P. (2021). The impact of menstrual cycle phase on athletes’ performance: a narrative review. International journal of environmental research and public health, 18(4), 1667.