The menstrual cycle is a complex physiological process that impacts various areas and aspects of a woman’s life. From energy and mood fluctuations to body temperature and even the way, the body absorbs nutrients. But what about muscle strength and training adaptation?
There have been a number of research studies conducted on this topic, however, the results are not very clear. Some studies suggest that there might be a small increase in muscle strength during the ovulation phase. However, other studies have not found any significant differences in muscle strength throughout the cycle.
The most recent research paper on this topic titled “Current evidence shows no influence of women's menstrual cycle phase on acute strength performance or adaptations to resistance exercise training,” sparked debate online with different experts, athletes and people weighing into the debate.
As we were sent the article a few times on social, we thought it would be worth reviewing the paper as well as previous studies on this topic.
Study Summary: “Current evidence shows no influence of women's menstrual cycle phase on acute strength performance or adaptations to resistance exercise training”
This study investigates the effects of the menstrual cycle phase on exercise performance, specifically resistance exercise training (RET), and related adaptations. The authors note that women are often excluded from exercise science research due to the assumption that cyclical fluctuations in reproductive hormones influence exercise performance and related adaptations.
The authors conducted an umbrella review, examining and critically evaluating evidence from existing meta-analyses and systematic reviews. Their investigation revealed highly variable findings among the published reviews regarding the effects of female sex hormones on outcomes relevant to resistance exercise training, including strength, exercise performance, and muscle hypertrophy.
The reality is that without measuring sex hormones concentrations research around the menstrual cycle is largely up to guesswork and algorithms. Especially because there is so much variation between people and between cycles.
So it's important to note that this article does not say that the menstrual cycle does not impact strength, but more so that research conducted so far has failed to demonstrate that it does.
We looked at some other papers on this topic:
Study: The Influence of the Menstrual Cycle on Muscle Strength and Power Performance
Sample Size: 13 female triathletes with regular menstrual cycles and at least six months of resistance training experience
Exercise Protocol: The participants performed the Smith machine half-squat exercise at maximal velocity with loads corresponding to 20, 40, 60, and 80% of their one-repetition maximum (1RM) in each of the three menstrual cycle phases: early follicular phase (EFP), late follicular phase (LFP), and mid-luteal phase (MLP).
Results: The study suggests that resistance-trained eumenorrheic females exhibit similar velocity, force, and power performance during the Smith machine half-squat exercise across different phases of the menstrual cycle, regardless of the loads used. Further research is needed to explore the effects of the menstrual cycle on women with irregular/abnormal cycles and the long-term adaptations to resistance training in relation to hormonal fluctuations.
Study: The isolated and combined effects of menstrual cycle phase and time-of-day on muscle strength of eumenorrheic females
Study Design: The study was conducted to analyze the isolated and combined effects of circamensal variation (changes over the course of the menstrual cycle) and diurnal changes (changes over the course of a day) on muscle strength.
Sample Size: 8 females (age 30 +/- 5 yrs, height 1.63 +/- 0.06m and body mass 66.26 +/- 4.6kg: mean +/- SD) with regular menstrual cycle
Exercise Protocols: Isokinetic peak torque of knee extensors and flexors of the dominant leg were measured at two times-of-day (06:00, 18:00 h) and five time points of the menstrual cycle (menses, mid-follicular, ovulation, mid-luteal, late luteal).
Results: The phase of the menstrual cycle seemed to have a greater effect than the time-of-day on female muscle strength in this group of subjects. The present results suggest that peripheral rather than central mechanisms (e.g., motivation) are implicated in the diurnal variation of maximal isometric strength of women.
Study 3: Menstrual Cycle and the Prevalence of Premenstrual Syndrome/Premenstrual Dysphoric Disorder in Adolescent Athletes
Sample Size: 40 women, 30 of which had regular cycles and 10 on oral contraceptive
Results: The study found no direct relationship between sex hormone variations and physical performance measures. However, positive associations were found between physical performance outcomes and factors such as self-reported motivation, perception of physical performance level, pleasure level, and arousal level. However, it’s worth noting that women on oral contraceptive pills do not experience menstruation or the phases of the menstrual cycle and as such should not be included in a study to assess the influence of the menstrual cycle on muscle performance.
My personal experience with strength at different phases of my cycle
Just before and during my period, I experience a significant drop in energy levels and various physical symptoms such as backache, muscle soreness, fatigue, and brain fog, which make it challenging to find the energy to work out, especially when work is hectic. During this time, I prefer to keep my workouts light, and simply showing up to the gym feels like a victory in itself.
However, things change around day 7 when the fatigue lifts and I feel an increase in energy and mood. This allows for better and more intense workouts. I usually take the opportunity to slightly increase the weight I'm lifting to challenge myself and get accustomed to the next level. As I enter the Luteal phase, I maintain the weight I explored in the follicular phase. While my strength doesn't fluctuate much, I don't feel the strength or energy to continue with progressive overload, so I focus on getting comfortable with the weight I experimented with earlier in my cycle.
To illustrate progressive overload with squats in different phases of my cycle, let's consider my starting working weight as 70kg for 5 sets of 5 reps:
- Day 3 - gentle leg workouts to help get back into the gym. 60kg Squats 3-5 sets, 5 reps
- Day 6 - 70kg for 5 sets, 5 reps (where I would have left off the previous month)
- Day 10 - 70kg for 1 set, 72.5kg for 4 sets
- Day 13 - 70 kg for 1 set, 72.5kg for 2 sets, 75kg for 2 sets
- Day 17 - 70 kg for 1 set, 72.5kg for 2 sets, 75kg for 2 sets
- Day 20 - 70kg for 1 set, 72.5kg for 4 sets
- Day 25 - 70kg for 2 set, 72.5kg for 3 sets
- Day 27-29 - light workout, walk, plenty of sleep and rest
- Day 6 - 70kg for 2 set, 72.5kg for 3 sets (where I would have left off the previous month)
- Day 10 - 70 kg for 1 set, 72.5kg for 2 sets, 75kg for 2 sets
- Day 13 - 72.5kg for 2sets, 75kg for 3 sets
- Day 17 - 72.5kg for 1 sets, 75kg for 4 sets
- Day 20 - 72.5 kg for 3 sets, 72.5kg for 2 sets
- Day 25 - 70kg for 3 sets, 72.5kg for 2 sets
- Day 6 - 70kg for 3 sets, 72.5kg for 2 sets (where I would have left off the previous month)
- Day 10 - 72.5kg for 1 set, 75kg for 4 sets
- Day 13 - 75kg 5 sets
- Day 17 - 75kg 5 sets
- Day 20 - 72.5kg for 1 set, 75kg for 4 sets
- Day 25 - 72.5kg for 1 set, 75kg for 4 sets
You could increase the weight faster, however, I find that this works well for me. It allows me to get stronger at a comfortable pace.
Understanding and tracking how your menstrual cycle affects you personally is crucial because every person is unique. It's important to recognize when certain symptoms occur and how intense they are for you individually. It's worth noting that as you age, the timing and intensity of your symptoms may also change. By consistently tracking (through an app or in a journal) and becoming self-literate about your own cycle, you can gain valuable insights and effectively manage your well-being.
- Czajkowska M, Drosdzol-Cop A, Gałązka I, Naworska B, Skrzypulec-Plinta V. Menstrual Cycle and the Prevalence of Premenstrual Syndrome/Premenstrual Dysphoric Disorder in Adolescent Athletes. J Pediatr Adolesc Gynecol. 2015 Dec;28(6):492-8. doi: 10.1016/j.jpag.2015.02.113. Epub 2015 Mar 6. PMID: 26233292. - https://pubmed.ncbi.nlm.nih.gov/26233292/
- Bambaeichi E, Reilly T, Cable NT, Giacomoni M. The isolated and combined effects of menstrual cycle phase and time-of-day on muscle strength of eumenorrheic females. Chronobiol Int. 2004 Jul;21(4-5):645-60. doi: 10.1081/cbi-120039206. PMID: 15470960. - https://pubmed.ncbi.nlm.nih.gov/15470960/
- Pallavi LC, D Souza UJ, Shivaprakash G. Assessment of Musculoskeletal Strength and Levels of Fatigue during Different Phases of Menstrual Cycle in Young Adults. J Clin Diagn Res. 2017 Feb;11(2):CC11-CC13. doi: 10.7860/JCDR/2017/24316.9408. Epub 2017 Feb 1. PMID: 28384857; PMCID: PMC5376807. - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376807/
- Janse de Jonge XA. Effects of the menstrual cycle on exercise performance. Sports Med. 2003;33(11):833-51. doi: 10.2165/00007256-200333110-00004. PMID: 12959622. - https://pubmed.ncbi.nlm.nih.gov/12959622/
- Fridén C, Hirschberg AL, Saartok T. Muscle strength and endurance do not significantly vary across 3 phases of the menstrual cycle in moderately active premenopausal women. Clin J Sport Med. 2003 Jul;13(4):238-41. doi: 10.1097/00042752-200307000-00007. PMID: 12855926. - https://pubmed.ncbi.nlm.nih.gov/12855926/
- Dam TV, Dalgaard LB, Sevdalis V, Bibby BM, Janse DE Jonge X, Gravholt CH, Hansen M. Muscle Performance during the Menstrual Cycle Correlates with Psychological Well-Being, but Not Fluctuations in Sex Hormones. Med Sci Sports Exerc. 2022 Oct 1;54(10):1678-1689. doi: 10.1249/MSS.0000000000002961. PMID: 36106832; PMCID: PMC9473716.