A woman’s menstrual cycle has different phases, the menstrual, follicular, ovulation and the luteal phase which is more commonly broken down in to two main phases; the follicular and luteal phase. The female reproductive hormones which rise and fall throughout the menstrual cycle, are known to affect numerous cardiovascular, respiratory, thermoregulatory and metabolic parameters, which in turn, may have implications on exercise physiology.
- Follicular Phase – This begins on day one of your period and continues until ovulation, a total of around 16 days. During this phase, the pituitary gland releases follicle stimulating hormone (FSH).
- Ovulation Phase – Luteinizing hormone (LH) is released in response to the follicular phase’s rising estrogen levels. One sign that implicates you’re in the ovulation phase is an increased body temperature which happens around day 14 of your cycle.
- Luteal Phase – This is where we will see a rise in progesterone and a slight bump in estrogen levels followed by a drop in both hormones and the restart of the cycle (barring pregnancy). The luteal phase is when women experience PMS symptoms such as bloating, headaches, weight changes, food cravings and trouble sleeping. This phase lasts between 11 – 17 days in total.
Differences in endurance performance during various phases of the menstrual cycle have been postulated to be due to differences in heat regulation, substrate availability, and metabolism. It is well documented that a female’s basal body temperature can differ between phases in the region of 0.3–0.5˚C. This elevation in temperature has been attributed to the surge of progesterone exhibited during the luteal phase. The associated increase in body temperature has been suggested to limit prolonged exercise capabilities and increase cardiovascular strain. It may be advisable to complete Low Intensity Steady State (LISS) training during the luteal phase and save your higher intensity workouts until the luteal phase is over. This is when your heart is working slightly harder than normal, which means your heart rate will increase at a faster rate. If you enjoy endurance training don’t be surprised if you struggle to train in your “normal” heart rate zones during the menstrual phase as peak heart rate is found to be lower during this phase. One option is to opt for High Intensity Interval Training (HIIT) workouts during this phase.
Low Intensity Steady State (LISS)
10 – 20 minutes moderate paced walk with incline on the treadmill.
10 – 20 minutes cycle on stationary bike with low to medium resistance.
High Intensity Interval Training (HIIT)
1 – 2 sets : 8 – 12 reps – 30 seconds running on treadmill at 80 – 100% perceived effort with 30 – 60 seconds rest (straddle treadmill or walking).
1 – 2 sets : 8 – 12 reps – 30 seconds cycling on a bike at 80 – 100% perceived effort with 30 – 60 seconds rest (slow cycle).
There has been no difference on strength training found during each of the phases during the menstrual cycle for women. We would encourage you to continue your strength training programme throughout. The only limiting factor may be during the Luteal Phase when you have PMS symptoms and feel tired/fatigued. If you are feeling fatigued consider reducing the overall volume of your strength session (e.g., completing half the number of sets for each exercise), this way you are still promoting a muscle growth response needed but not taxing your body too much in a way which will promote increased fatigue/tiredness.