This article was written by one of our contributors: PhD student and found of Period of the Period – Kelly McNulty.
It’s not all about cardio, strength training is equally important for health. Strength training has numerous physical and psychological benefits for everyone:
- Increased lean muscle mass: During peri-menopause and beyond – because of changes in hormones – women can lose muscle mass at a rate of ~3% per decade so strength training can help to offset this
- Improved bone density: Women lose between 2 to 3% of bone mass per year after menopause, so strength training is important to reduce bone loss and prevent osteoporosis.
- Reduced body fat
- Enhanced resting metabolic rate
- Improved blood glucose control and insulin sensitivity
- Can help reduce symptoms of depression and anxiety
- Improved sporting performance
- Reduced likelihood of injury
- Improved body confidence and self-esteem (1,2)
As such, regular strength training should be a part of everyone’s training plans in some form. Exercise guidelines recommend that adults do some form of resistance training (e.g., muscle strengthening exercises) on at least two of the week, working your major muscle groups (e.g., legs, arms, back and core).
De-bulking the myths
Whilst less women are worrying that they’ll end up with Arnold Schwarzenegger quads and biceps as a result of lifting, it’s still a common misconception that strength training can make women ‘bulky’ and often many women will avoid this type of activity because of this fear. Additionally, there are extra factors feeding into this concern, for instance, the stigma surrounding female muscularity (although this is starting to change with strength being more and more celebrated over the previous ideal of being thin). Whilst your body size and shape will likely change with strength training, because of our female hormones it’s actually really difficult for women to get ‘bulky’ (unless really pushed following a specifically designed training program) and instead the majority of women report becoming leaner, stronger and feeling more powerful with strength training (and you might even notice the added bonus of feeling fabulous!)(3).
Tailoring your strength training to your menstrual cycle
The menstrual cycle is the name given to the cycle of hormonal fluctuations that occur roughly every month in women of reproductive age (from menarche to menopause) for the purpose of allowing reproduction. The menstrual cycle in its simplest form can be broken down into two phases:
#1 the follicular phase
which begins on the first day of your period and runs until ovulation
#2 the luteal phase
which runs from ovulation through until the day before your next period arrives. During the early follicular phase (the time when you’re on your period) oestrogen and progesterone levels are both low, however throughout the mid- to late-follicular phase oestrogen levels begin to rise and reach a peak just prior to ovulation, whilst progesterone levels remain low. In contrast, during the luteal phase both oestrogen and progesterone levels are high before decreasing again towards the end of this phase to allow the cycle to begin again.
Aside from their reproductive roles, both oestrogen and progesterone have numerous physiological effects outside of the reproductive system.. For example, oestrogen is known for its anabolic and muscle-building effects and can therefore influence skeletal muscle strength and size, hypertrophy, protein synthesis, and might also play a key role in muscle repair and regeneration (4). In contrast, progesterone is thought to inhibit the effects of oestrogen, with some researchers even reporting a catabolic effect of progesterone (although more research is needed to understand progesterone’s effect on muscle)(4). Given these potential effects and that oestrogen and progesterone receptors have been found in skeletal muscle, variations in these sex hormones across the menstrual cycle might influence strength training outcomes in women.
Menstrual cycle phase-based strength training (aka planning your strength training around your menstrual cycle) might lead to bigger adaptation gains for some women. Specifically, studies to date suggest that performing more strength training sessions during the follicular phase of your menstrual cycle (e.g., 4 sessions per week in the first half of your cycle and 1-2 sessions per week in the second half) is superior to focusing more strength sessions during your luteal phase or spreading them evenly across your cycle (e.g., 3 sessions per week across the entire cycle) – for developing strength and lean muscle mass)(5-7). So, based on the research, aim to focus most of your strength training sessions during the follicular phase of your cycle (where possible)(8).
*Reminder: If you’re upping your strength training in your follicular phase it’s essential to balance this added training with appropriate rest, recovery, and nutrition in order to get the most out of your training.
Time for a giant caveat. Whilst it’s exciting to think that as women we could take advantage of our physiology across the menstrual cycle to gain these types of advantages, it’s important to note that only four studies to date have investigated menstrual cycle phase-based strength training, which makes it difficult for us to draw clear conclusions from these studies. Additionally, each of these studies have method issues (i.e., differing study designs, small participant numbers, failure to measure oestrogen and progesterone to confirm menstrual cycle phase and even the grouping together of hormonal contraceptive users with naturally menstruating women in results), indicating that the results should be taken with caution.
Takeaway message
There are numerous physical and psychological benefits of strength training, especially for women. Additionally, the effects of oestrogen on skeletal muscle are promising and if you start paying attention to your cycle, you might find that you get the most out of your strength training by scheduling it within your follicular phase. However, further research is needed before evidenced-based guidelines can be formed and the best advice for now is to simply go with how you feel. For instance, rather than pushing yourself through a heavy strength training session towards the end of your luteal phase (when you might be suffering from lots of different pre-menstrual symptoms) switch the activity or give yourself a break, and instead schedule that session for another day when you’ll be able to get the most out of yourself. To help with this, start tracking your cycle and collecting your own data to inform how you might adapt your strength training across your cycle (i.e., when it’s good to push yourself and when you should take a step back).
References
(1) Kraemer, W. J., Ratamess, N. A., & French, D. N. (2002). Resistance training for health and performance. Current Sports Medicine Reports, 1(3), 165-171.
(2) Westcott, W. L. (2012). Resistance training is medicine: effects of strength training on health. Current Sports Medicine Reports, 11(4), 209-216.
(3) Hagstrom, A. D., Marshall, P. W., Halaki, M., & Hackett, D. A. (2020). The effect of resistance training in women on dynamic strength and muscular hypertrophy: a systematic review with meta-analysis. Sports Medicine, 50(6), 1075-1093.
(4) Knowles, O. E., Aisbett, B., Main, L. C., Drinkwater, E. J., Orellana, L., & Lamon, S. (2019). Resistance training and skeletal muscle protein metabolism in eumenorrheic females: Implications for researchers and practitioners. Sports Medicine, 49(11), 1637-1650.
(5) Reis, E., Frick, U., & Schmidtbleicher, D. (1995). Frequency variations of strength training sessions triggered by the phases of the menstrual cycle. International Journal of Sports Medicine, 16(08), 545-550.
(6) Sung, E., Han, A., Hinrichs, T., Vorgerd, M., Manchado, C., & Platen, P. (2014). Effects of follicular versus luteal phase-based strength training in young women. Springerplus, 3(1), 1-10.
(7) Wikström-Frisén, L., Boraxbekk, C. J., & Henriksson-Larsen, K. (2017). Effects on power, strength and lean body mass of menstrual/oral contraceptive cycle-based resistance training. Journal of Sports Medicine and Physical Fitness, 57(1-2), 43-52.
(8) Thompson, B., Almarjawi, A., Sculley, D., & de Jonge, X. J. (2020). The effect of the menstrual cycle and oral contraceptives on acute responses and chronic adaptations to resistance training: A systematic review of the literature. Sports Medicine, 50(1), 171-185.
