Syncing exercise and nutrition with your monthly cycle

• Metabolism basics and the menstrual cycle
• Understanding the monthly cycle
• The five monthly cycle phases

When we think of our menstrual cycle, our minds might jump to cramps, bloating, cravings, and low energy. But there’s actually a lot more going on.

As a woman, you know that your monthly cycle may impact many aspects of your life. But, what if you could understand more about your monthly cycle and hormones and use this knowledge to adjust your lifestyle habits to work in sync with your physiology and metabolism?

The good news is, you can! 

By understanding your cycle and making some simple adjustments, you can work with your body, not against it.

Metabolism basics and the menstrual cycle

A woman’s metabolism changes throughout the month in distinct phases. Hormones play a crucial role in regulating metabolism [1,2], and the menstrual cycle can affect how the mitochondria, your cells’ powerhouses, produce energy from carbs and fats [3].

Lumen’s research [3] has identified changes in CO₂ levels in each monthly cycle phase.  CO₂ is a fundamental marker of metabolic activity in the human body and provides valuable insights into physiological processes [4]. Higher  CO₂  levels indicate carb burn, while lower  CO₂ levels point to fat burn. 

In the follicular phase – the first half of the monthly cycle leading up to ovulation – estrogen rises and progesterone is low, causing higher exhaled CO₂. In the luteal phase following ovulation, as progesterone increases and estrogen drops, exhaled CO₂ is lower [3].

Becoming aware of these shifts during your monthly cycle can help you understand your body and sync your nutrition and fitness to your physiology.

Understanding the monthly cycle

Before we discuss nutrition and fitness, it is important to understand the monthly cycle. This complex process involves the release of hormones, follicle growth in the ovaries, and shedding of the uterine lining.

Different hormonal changes and physiological responses characterize each phase.

The cycle typically lasts 28-32 days and consists of five phases:

• Menstruation (Day 1-7)
• Mid-follicular phase (Day 7-13)
• Ovulation (Day 14)
• Post-ovulation (Day 15-21)
• Pre-menstrual phase (Day 22-28)

Menstruation

This is the first phase of the menstrual cycle and lasts about 3-7 days. During this time, the uterus sheds its lining, which results in bleeding. Hormone levels, specifically estrogen and progesterone, are low during this phase. This means there’s no significant impact on what the mitochondria choose for fuel.

However, in this phase, you might experience higher levels of inflammation [5] and the stress hormone cortisol [6]. Because cortisol tells your mitochondria to switch to carbs for a quick power boost, you may notice your Lumen levels are higher in the menstrual phase.

Nutrition recommendations

• Eat an antioxidant-rich diet. Antioxidants found in green veggies, sweet potatoes, red cabbage, berries, and green tea can help you better manage menstrual cycle symptoms and support your immune system.
• Prevent inflammation and menstrual cramps by eating anti-inflammatory foods rich in polyphenols and omega-3 fatty acids found in nuts, ginger, turmeric, dark chocolate, seeds, and extra virgin olive oil.
• Reach for iron-rich foods like spinach, red meat, dark chocolate, liver, and lentils to replenish your blood loss. To optimize iron absorption, eat vitamin C-rich foods like citrus fruits, peppers, and broccoli.
• Stay hydrated throughout your period to prevent headaches, bloating, and water retention.
• Beat cramps with ginger tea. Ginger’s natural anti-inflammatory effects help soothe aching muscles and ease cramps.

Fitness recommendations according to our metabolic coaches:

Try incorporating low-intensity workouts into your day, like a walk or stretching, to alleviate menstrual cramps. Gentle exercises like yoga or walking can help soothe cramps and improve mood.

The mid-follicular phase

During phase two of the monthly cycle, days 7 through 13, your mitochondria are more likely to use carbs for energy [3]. During these days, progesterone is still low, while estrogen increases. 

When estrogen levels increase, the body tends to rely more on carbohydrates as a primary energy source. This is partly due to estrogen’s effect on enhancing glycolysis [7], which promotes the breakdown of glucose to produce energy. You may also experience increased energy and motivation.

Nutrition recommendations

• Consume slow-absorption carbs, such as rolled oats, whole grains, quinoa, barley, lentils, and beans. These foods can help prevent insulin spikes and reduce hunger cues during ovulation.
• Eat your carbs in the first half of your day.
• Have dinner earlier to extend the length of your overnight fast.
• Choose healthy fats high in omega-3 and 9 fatty acids, found in salmon, seaweed, avocado, pure cacao, and eggs.

Fitness recommendations according to our metabolic coaches:

Now can be an excellent time to turn up the intensity of your workouts.

To take advantage of your increased energy levels, you may benefit from high-intensity interval training (HIIT) and strength training.

Carbohydrates fuel your workouts, while protein helps build and repair muscle tissue post-workout.

Ovulation 

Ovulation is the third phase of the menstrual cycle and typically occurs around day 14. This is when the mature follicle releases an egg, which can be fertilized by sperm. During ovulation, hormone levels, especially luteinizing hormone (LH) and follicle-stimulating hormone (FSH), peak. During this time, the body tends to burn more carbs for fuel. 

Nutrition recommendations

• Enjoy healthy fat sources, including avocado, nuts and seeds, and salmon.
• Increase your intake of antioxidant-rich foods like berries to support your immune system. 

Fitness recommendations according to our metabolic coaches:

You can continue with high-intensity exercise like sprinting and weightlifting. An added perk of high-intensity workouts is that they can help your mitochondria use carbs more efficiently.

Post-ovulation 

Post-ovulation is part of the luteal phase of the monthly cycle and lasts from days 15 to 21. During this phase, the follicle that releases the egg becomes the corpus luteum, which increases progesterone levels. Post-ovulation marks the start of the luteal phase and a greater propensity for fat burn.

Nutrition recommendations

• Eat healthy fats. During this phase, when waking up with lower Lumen levels, your fat target may be higher. This is the perfect time to enjoy healthy fat sources, like avocado, nuts and seeds, and salmon.
• Consume 20-30g of protein like meat, cottage cheese, chicken breast, tofu, and tuna at every meal. Studies show that estrogen can promote protein synthesis and reduce muscle breakdown [8]. Because estrogen is low in the luteal phase, you can preserve your muscle mass by eating adequate protein.
• Manage hunger by adding plenty of vegetables to every meal for extra fiber [9]. Research shows that during the mid- and late luteal phase, your stomach and small intestine release more ghrelin, a hunger-stimulating hormone.
• Try kale, broccoli, onions, garlic, and radishes to help your liver process excess estrogen. High estrogen levels during this phase can trigger breakouts. 

Fitness recommendations according to our metabolic coaches:

To elevate your overall activity level, you can incorporate aerobic exercise to promote fat burning, such as walking, cycling, or light jogging. 

Considering your morning levels might be lower in the luteal phase, it might be helpful to complete a pre-workout breath measurement about 30 minutes to an hour before exercise to determine if fueling up would be beneficial. This can ensure you stay in tune with what’s happening on both a metabolic and hormonal level to get the most out of your exercise sessions!

The pre-menstrual phase

During the final phase of a woman’s monthly cycle, days 22-28, both progesterone and estrogen decrease. Lumen’s research found that CO₂ levels drop in the pre-menstruation phase, indicating increased fat burn. 

Additionally, research has observed that carb utilization tends to be lower in the early follicular phase [10], suggesting that fat burn may increase during the late luteal phase. 

Nutrition recommendations

• Ease mood swings by eating serotonin boosters like leafy greens, tofu, eggs, cashews, almonds, and pumpkin seeds. This helps address the drop in serotonin, a hormone involved in sleep, appetite, and mood regulation, due to an increase in SERT (serotonin transporter) [11]. 
• Go for tryptophan-rich foods like turkey, sesame seeds, bananas, milk, and spirulina, which can help you sleep better.
• Focus on non-processed foods. You might experience an increase in cravings for processed foods. To reduce cravings, increase your consumption of whole foods, especially vegetables and fruits.
• Reach for dark chocolate, spinach, pumpkin seeds, and bananas. These foods are magnesium-rich and help fight fatigue and lift a low libido.
• Get more B vitamins, which help ward off PMS. Choose leafy greens, seafood, whole grains, beans, and lentils.
• Eat every 3-4 hours to ensure your energy needs are supported in preparation for your upcoming period.

Fitness recommendations according to our metabolic coaches:

Pay attention to your body. If you’re feeling tired, take the time to rest or focus your fitness on reducing stress - whether through yoga, pilates, or jogging. The more you align with your body’s needs and let it rest and recover, the better it will serve you through the other phases of your cycle. 

Work in sync with your physiology

As a woman, your menstrual cycle can affect many aspects of your life, including your metabolism. By understanding the different phases of your cycle and making simple adjustments to your diet and exercise routine, you can work in sync with your metabolism and feel your best.

Lumen’s cycle tracking leverages every cycle phase to make your metabolism work for you. You’ll find personalized recommendations for each day suited to your phase and physiology.

Disclaimer

The information Lumen provides is for educational and informational use only. You should seek the advice of your physician or other healthcare providers with any questions regarding your health.

References

[1] Draper, C. F., Duisters, K., Weger, B., Chakrabarti, A., Harms, A. C., Brennan, L., Hankemeier, T., Goulet, L., Konz, T., Martin, F. P., Moco, S., & van der Greef, J. (2018). Menstrual cycle rhythmicity: metabolic patterns in healthy women. Scientific reports, 8(1), 14568. https://doi.org/10.1038/s41598-018-32647-0

[2] Benton, M. J., Hutchins, A. M., & Dawes, J. J. (2020). Effect of menstrual cycle on resting metabolism: A systematic review and meta-analysis. PloS one, 15(7), e0236025. https://doi.org/10.1371/journal.pone.0236025 

[3] Cramer, T., Yeshurun, S., & Mor, M. (2024). Changes in Exhaled Carbon Dioxide during the Menstrual Cycle and Menopause. Digital biomarkers, 8(1), 102–110. https://doi.org/10.1159/000539126

[4] Livesey, G., & Elia, M. (1988). Estimation of energy expenditure, net carbohydrate utilization, and net fat oxidation and synthesis by indirect calorimetry: evaluation of errors with special reference to the detailed composition of fuels. The American journal of clinical nutrition, 47(4), 608–628. https://doi.org/10.1093/ajcn/47.4.608

[5] Brown, N., Martin, D., Waldron, M., Bruinvels, G., Farrant, L., & Fairchild, R. (2023). Nutritional practices to manage menstrual cycle related symptoms: a systematic review. Nutrition research reviews, 1–24. Advance online publication. https://doi.org/10.1017/S0954422423000227

[6] Hamidovic, A., Karapetyan, K., Serdarevic, F., Choi, S. H., Eisenlohr-Moul, T., & Pinna, G. (2020). Higher Circulating Cortisol in the Follicular vs. Luteal Phase of the Menstrual Cycle: A Meta-Analysis. Frontiers in endocrinology, 11, 311. https://doi.org/10.3389/fendo.2020.00311

[7] Rettberg, J. R., Yao, J., & Brinton, R. D. (2014). Estrogen: a master regulator of bioenergetic systems in the brain and body. Frontiers in neuroendocrinology, 35(1), 8–30. https://doi.org/10.1016/j.yfrne.2013.08.001

[8] Kodete, C. S., Thuraka, B., Pasupuleti, V., & Malisetty, S. (2024). Hormonal influences on skeletal muscle function in women across life stages: A systematic review. Muscles, 3(3), 271–286. https://doi.org/10.3390/muscles3030024  

[9] Mlyczyńska, E., Kieżun, M., Kurowska, P., Dawid, M., Pich, K., Respekta, N., Daudon, M., Rytelewska, E., Dobrzyń, K., Kamińska, B., Kamiński, T., Smolińska, N., Dupont, J., & Rak, A. (2022). New Aspects of Corpus Luteum Regulation in Physiological and Pathological Conditions: Involvement of Adipokines and Neuropeptides. Cells, 11(6), 957. https://doi.org/10.3390/cells11060957 

[10] Bisdee, J. T., Garlick, P. J., & James, W. P. (1989). Metabolic changes during the menstrual cycle. The British journal of nutrition, 61(3), 641–650. https://doi.org/10.1079/bjn19890151

[11] Sacher, J., Zsido, R. G., Barth, C., Zientek, F., Rullmann, M., Luthardt, J., Patt, M., Becker, G. A., Rusjan, P., Witte, A. V., Regenthal, R., Koushik, A., Kratzsch, J., Decker, B., Jogschies, P., Villringer, A., Hesse, S., & Sabri, O. (2023). Increase in Serotonin Transporter Binding in Patients With Premenstrual Dysphoric Disorder Across the Menstrual Cycle: A Case-Control Longitudinal Neuroreceptor Ligand Positron Emission Tomography Imaging Study. Biological psychiatry, 93(12), 1081–1088. https://doi.org/10.1016/j.biopsych.2022.12.023