During a menstrual cycle hormone levels constantly change. And since hormones affect your metabolism, it wouldn’t be strange to assume that it could affect your weight loss efforts. But first, it would be of importance to understand the different phases of the cycle. The menstrual cycle can be divided into two separate cycles, there is the ovarian cycle and the uterine cycle. To better illustrate the time frame in which each phase takes place, I will be basing these of a 28-day cycle. However, I would like to note that cycle length and regularities are different for each individual and that many factors, including stress, diet, and drugs, can influence these.
What happens during your menstrual cycle?
Ovarian cycle. This cycle starts with the follicular phase, in which the ovarian follicles prepare to release an egg. This phase is roughly 14 days and halfway through (day 7) there will be an increase estrogen levels. Around the 14th day of the cycle, ovulation takes place, this is when an egg is released from the ovaries. This is when females are fertile and can get pregnant. After the follicular phase, the luteal phase kicks in. During this part of the cycle progesterone levels increase. The luteal phase is the part of the cycle during which women might experience premenstrual syndrome (PMS) (Biggs, & Demuth, 2011).
Uterine cycle. This cycle starts off with menstruation, during this time the inner lining of the uterus is shed. Afterward, the proliferative phase takes place, in which the lining of the uterus grows due to estrogen. And lastly, during the secretory phase, the progesterone levels increase and facilitates possible implementation of the blastocyst (this is the clump of cells formed 5 days after fertilization).
Do you burn more calories while on your period?
First of all, it is important to know what the basal metabolic rate (BMR) is. This is the amount of energy needed for a person to stay alive while at rest. BMR can be measured with calories as units of energy. And a calorie is a measurement of energy that is required to increase the temperature of water by 1 °C. You can calculate your BMR by using online calculators that will give you an estimation based on your height, weight, age, and gender. However, on top of your BMR, you also use calories to carry out your daily activities. So the total amount of calories you burn each day is actually higher than your BMR. But do you end up burning more calories during any time of your menstrual cycle?
1. Bisdee, James, & Shaw, (1989) found that the BMR is lowest during the late follicular phase and highest in late luteal phase. They found an increase of 6.1%, to illustrate what this might look like, here’s an example: if your BMR is 1500 calories, this would mean that your BMR is roughly 1592 calories. A difference of about 90 calories is equivalent to a small banana.
2. Different researchers found that the BMR decreased during menstruation, and was lowest a week before ovulation. From that point, the BMR would increase until the next menstruation (Solomon, Kurzer, & Calloway, 1982).
3. Webb (1986) found an increase of 8-16% in energy expenditure during the luteal phase (so after ovulation).
Do you retain more water during any phase of your cycle?
Symptoms such as fluid retention (and swollen breasts) are often talked about in regards to the menstrual cycle. Faratian, et al (1984) found that participants experienced bloating during PMS, however, actual body weight did not increase. Reid and Yen (1983) also point out that women report lower abdominal bloating, but that it rarely manifests in higher body weight. O’Brien, Selby, and Symonds, 1980 found that the participants did retain water and on average did increase in body mass, although, they did not find any consistent weight gain.
Does menstruation affect your cravings?
Gong, Garrel, and Calloway (1989) found a decrease in food intake during ovulation and an increase in the luteal phase. The intake per day was about 214 calories higher during the luteal phase than the follicular phase. And this might fit the idea that people experience more cravings during PMS, as it’s experienced during the luteal phase. Different researchers found similar results, an increase in energy and fat intake 10 days before menstruation (Tarasuk, & Beation, 1991). Lyon, et al (1989) also found a fall in food intake during ovulation. And many other studies also confirm an increase during the luteal stage (Buffenstein, Poppitt, McDevitt, & Prentice, 1995; Dalvit 1981; Pliner, & Fleming, 1983).
Can exercise affect the menstrual cycle? Or can the menstrual cycle affect exercise?
Bonen, et al (1979) found that the ovarian hormones in untrained individuals increased, but for trained individuals, nothing changed. However, it is difficult to interpret these results and to claim that this can have implications. Aganoff and Boyle (1994) found that individuals that regularly exercise score lower on negative mood affect and pain. Nicklas, Hackney, and Sharp (1989) found that performance and muscle glycogen content was enhanced during the luteal phase of the cycle. The luteal phase is the stage before menstruation. However, de Jonge (2003) reviewed different articles on this topic and concluded that the menstrual cycle does not influence performance or maximal oxygen consumption. Several studies have indicated that regular exercise can affect menstrual cramps (dysmenorrhea) experienced during menses. Regular exercise could aid in less dysmenorrhea (Abbaspour, Rostami, & Najjar, 2006; Golomb, Solidum, & Warren 1998); Hightower, 1998).
Do all of these scientific findings apply to me?
It seems as if the menstrual cycle has a small to no effect on calorie burning, weight gain, and exercise. Therefore these results should be considered with caution.
The idea behind scientific methodology is always to ensure that results are statistically significant and reliably measured. If these main principles are met, the results you found in a sample can be generalized to a population. But anyone can be an outlier that does not fit the findings. Sometimes researchers do find significant results, but the effect size might be very small. This might mean that the findings might be negligible when applied to daily life situations. It is also imperative to emphasize that many studies on the menstrual cycle do not have big samples of participants. These types of experiments might need constant measurement and screening of participants. Participants also have to stick to a set diet and might have to be sedentary during the experiment to cancel out any unwanted effects that food intake and exercise can create. These obligations make it difficult (and possibly more expensive) to test bigger samples. Unfortunately, smaller samples are detrimental to the overall validity of a study.
- Be aware of the fact that water retention might affect your numbers on the scale. Hormones and specific foods (high sodium intake) can make it seem as if you gained a lot of weight in a short period of time. If you suddenly drastically see your weight change, it is highly likely due to gaining or losing water weight. You can try to lose water weight by drinking more water or exercising (sweating it out).
- If you track your weight loss by measuring yourself (using a scale) it might be a good idea to figure out when you tend to retain water. If you get demotivated by the numbers on the scale going up, you might want to skip tracking yourself that week.
- Hormones can affect your cravings. If you tend to overeat during any part of your cycle, calculate this into your weight loss schedule. You might want to adjust your goals and accept that it might take longer than first anticipated. Not being able to meet your goals can be demotivating, so if you are just not able to lose the amount you had in mind, readjust! To quote Confucius: it doesn’t matter how slowly you go, as long as you don’t stop!
- Exercising during your menstruation shouldn’t be a problem. It might even help in relieving some of the pain and uncomfortableness associated with menstruation. However, if you prefer to skip exercise because the pain is unbearable and is keeping you bedridden, that is completely fine as well. Though, if exercise is part of your weight loss strategy, motivate yourself to continue once the pain and uncomfortableness are gone.
Abbaspour, Z., Rostami, M., & Najjar, S. H. (2006). The effect of exercise on primary dysmenorrhea. Journal of Research in Health sciences, 6(1), 26-31.
Aganoff, J. A., & Boyle, G. J. (1994). Aerobic exercise, mood states and menstrual cycle symptoms. Journal of psychosomatic research, 38(3), 183-192.
Biggs, W. S., & Demuth, R. H. (2011). Premenstrual syndrome and premenstrual dysphoric disorder. American family physician, 84(8).
Bisdee, J. T., James, W. P. T., & Shaw, M. A. (1989). Changes in energy expenditure during the menstrual cycle. British Journal of Nutrition, 61(02), 187-199.
Bonen, A., Ling, W. Y., MacIntyre, K. P., Neil, R., McGrail, J. C., & Belcastro, A. N. (1979). Effects of exercise on the serum concentrations of FSH, LH, progesterone, and estradiol. European journal of applied physiology and occupational physiology, 42(1), 15-23.
Buffenstein, R., Poppitt, S. D., McDevitt, R. M., & Prentice, A. M. (1995). Food intake and the menstrual cycle: a retrospective analysis, with implications for appetite research. Physiology & behavior, 58(6), 1067-1077.
Dalvit, S. P. (1981). The effect of the menstrual cycle on patterns of food intake. The American Journal of Clinical Nutrition, 34(9), 1811-1815.
Faratian, B., Gaspar, A., O’Brien, P. M. S., Johnson, I. R., Filshie, G. M., & Prescott, P. (1984). Premenstrual syndrome: Weight, abdominal swelling, and Perceived body image. American journal of obstetrics and gynecology, 150(2), 200-204.
Golomb, L. M., Solidum, A. A., & Warren, M. P. (1998). Primary dysmenorrhea and physical activity. Medicine & Science in sports & exercise, 30(6), 906-909.
Gong, E. J., Garrel, D., & Calloway, D. H. (1989). Menstrual cycle and voluntary food intake. The American journal of clinical nutrition, 49(2), 252-258.
Hightower, M. (1998). Effects of exercise participation on menstrual pain and symptoms. Women & health, 26(4), 15-27.
de Jonge, X. A. J. (2003). Effects of the menstrual cycle on exercise performance. Sports Medicine, 33(11), 833-851.
Lyons, P. M., Truswell, A. S., Mira, M., Vizzard, J., & Abraham, S. F. (1989). Reduction of food intake in the ovulatory phase of the menstrual cycle. The American journal of clinical nutrition, 49(6), 1164-1168.
Nicklas, B. J., Hackney, A. C., & Sharp, R. L. (1989). The menstrual cycle and exercise: performance, muscle glycogen, and substrate responses. International journal of sports medicine, 10(04), 264-269.
O’Brien, P. M., Selby, C., & Symonds, E. M. (1980). Progesterone, fluid, and electrolytes in premenstrual syndrome. Br Med J, 280(6224), 1161-1163.
Pliner, P., & Fleming, A. S. (1983). Food intake, body weight, and sweetness preferences over the menstrual cycle in humans. Physiology & Behavior, 30(4), 663-666.
Solomon, S. J., Kurzer, M. S., & Calloway, D. H. (1982). Menstrual cycle and basal metabolic rate in women. The American journal of clinical nutrition, 36(4), 611-616.
Reid, R. L., & Yen, S. S. C. (1983). The premenstrual syndrome. Clinical obstetrics and gynecology, 26(3), 710-718.
Tarasuk, V., & Beaton, G. H. (1991). Menstrual-cycle patterns in energy and macronutrient intake. The American journal of clinical nutrition, 53(2), 442-447.
Webb, P. (1986). 24-hour energy expenditure and the menstrual cycle. The American journal of clinical nutrition, 44(5), 614-619.
Source menstrual cycle diagram.