Leading sports dietitian and RD Lexi Moriarty, explains why your period doesn’t have to sideline your training, sharing six essential, expert-approved tips to help fuel your workouts, keeping you active and healthy during your menstrual cycle.
It’s almost inevitable that your period has disrupted your usual workout routine at some point. Physical symptoms like cramps, fatigue, and bloating can make exercise feel more challenging. While fluctuations in mood and heightened sensitivity that often accompany PMS can reduce your motivation, increase stress, and lead to self-consciousness.
For many women, the arrival of their period often means missing a workout. Even for those who do manage to exercise, feelings of underperformance can be discouraging. A 2019 study analyzing responses from over 14,000 women on Strava found that 88% of participants felt their exercise performance was negatively affected during their menstrual cycle¹. Yet, 78% of women said that exercise reduced the symptoms related to their menstrual cycle¹.
So, is it time we “flip the script” and harness the power of periods to enhance our physical and mental health, rather than seeing them as a means to disrupt our usual workout routine? And how can we maximize our training during our menstrual cycle?
Forget complicated diets – make sure you meet your baseline nutritional needs
Most people who menstruate burn slightly more calories than normal, particularly during the luteal phase, so it’s really important to be able to cover all of those needs. Being aware of this and attuned to it can help to avoid any potential energy deficits or period-related fatigue.
No matter what phase of the cycle you’re in, it’s really important to be able to cover all of your baseline energy needs on a daily basis.
Hear it from the expert
“Regardless of how you balance your macronutrients, failing to meet your essential needs can lead to low energy availability, both in the short and long term. This will heighten your risk of fatigue, diminish the intensity of your workouts, and leave you feeling sluggish throughout the day.”
Lexi Moriarty, certified sports dietitian
“For many women, we focus on the quality of our diet and overlook whether we’re actually adequately meeting our body’s energy needs during the menstrual cycle. Diet culture can make us think we shouldn’t eat more, especially when we experience increased cravings and wonder why we feel hungrier and less satisfied. However, there’s a physiological reason behind these feelings. It’s crucial to listen to your body and understand its signals.”
When it comes to working out on your period, carbs aren’t the enemy!
Carbohydrates are your body’s preferred source of energy, and this holds true throughout your menstrual cycle. For active women, it’s crucial to replenish glycogen stores to maintain performance and health.
Incorporate a variety of carbs such as starches, fruits, starchy vegetables, beans, and dairy into your meals and snacks. By doing so, you support a healthy menstrual cycle, reduce the risk of injuries, and enhance your overall performance.
“Carbohydrates are the most easily available energy source to your body and something that we’re pulling on constantly, anytime that we’re doing any type of exercise,” says Moriarty. “If you’re not giving your body enough carbohydrates, you’ll not only have a higher risk of fatigue and lower-intensity workouts, but you’ll also have less stamina.”
“So that’s why it’s really important that we have more exogenous sources of carbohydrates available, especially before or during a workout, if it’s longer than an hour,” adds Moriarty. “It can also be really important for recovery after a workout. So we might need to pay a bit more attention to our carbohydrate needs and how much we need to recover from an intense workout.”
But what if you’re struggling to eat? Here’s where a liquid lunch is the perfect option
Each of us reacts differently to our periods. The menstrual cycle can affect your appetite, often increasing it for many girls and women. However, symptoms like nausea, bloating, fatigue, constipation, and diarrhea can reduce the desire to eat, making the idea of maintaining a balanced, nutrient-rich diet of fiber, fruit, and protein seem distant.
“If eating solid food is challenging, focus on liquid calories such as smoothies, shakes, and pre-made protein drinks,” says Moriarty. “These can be easier to tolerate, especially if you’re experiencing nausea, gastric distress, or pain. Ensuring you drink plenty of liquids can also alleviate bloating and constipation.
“Ensure you’re incorporating frequent snacks throughout the day, as they can often be better tolerated than three large meals. In my opinion, all active women should include snacks in their daily routine, but during menstruation it might be helpful to add a few more than usual.”
Here’s why you should be prioritizing protein
Active women require more protein than their sedentary counterparts to aid muscle recovery and achieve body composition goals. Instead of consuming a large amount of protein in one meal, spread it out throughout the day to optimize muscle protein synthesis. Aim for 20-50 grams of protein at most meals and 10-20 grams at snacks. This consistent protein intake helps your body repair and build muscle effectively.
“Just as women can benefit from consuming slightly more carbohydrates during the follicular phase, the early part of the menstrual cycle, it’s beneficial to focus on meeting protein goals during the luteal phase, the latter part of the cycle,” says Moriarty. “Aim for 1.2 to 2.2 grams of protein per kilogram per day. This ensures optimal nutrition throughout the different phases of the menstrual cycle.”
Most people don’t realize the importance of your iron intake
Good iron levels and stores are critical for athletes and heavy exercisers due to the key role it plays in the production of myoglobin, a protein that carries and stores oxygen specifically in muscle tissue. Thus, low levels or depletion will have a significant negative impact on performance.
Iron deficiency is a common phenomenon in athletes, particularly those involved in endurance sports. It has been reported to impact 15-35% of female athletes². Active women are at further risk of low iron due to monthly menstrual losses. Monthly periods are the most common cause of iron loss, with women of childbearing age needing almost two times more daily iron than men³.
While this varies from female to female, most women will lose 20-90 ml of blood during their period. Those who have heavy periods can have losses in excess of 160 ml during their monthly cycle*. With a reported 1 in 3 women suffering from heavy menstrual bleeding**, the risks are high for many active women.
“To counter this, incorporate iron-rich foods into your diet. Animal-based sources like pork, ground beef, eggs, and dark meat chicken are highly bioavailable and can help maintain blood levels during this time and positively benefit concentration and fatigue, especially during the earlier phase of the menstrual cycle. Plant-based sources such as spinach, broccoli, nuts, seeds, beans, and whole grains are also beneficial. Pairing these foods with vitamin C-rich items like citrus fruits or orange juice can enhance iron absorption.
“Female athletes tend to be at a higher risk of not meeting their needs, as they have busier schedules, or they can be susceptible to diet culture, as we all are,” Moriarty explains. “All of these things can make it harder for us to meet our vitamin and mineral needs on a daily basis from just our diet alone. So that’s where supplements come in.”
Iron supplements can help with or address low iron levels, and are especially beneficial for female athletes who struggle to meet their iron requirements through diet alone.
Selecting the right iron supplement is crucial, as many cause side effects like nausea, constipation, and altered bowel habits, leading women to discontinue use or impact their training. Active Iron, for example, is clinically proven to improve iron levels while being gentle on the stomach, offering an effective and tolerable option for iron supplementation.
The bottom line is you must listen to your body
Understanding your body’s needs is crucial, but it’s equally important to listen to it. If you find yourself craving more carbs, protein, or fats, pay attention to these signals. Your body often knows what it needs better than any external advice. While it’s important to have a structured nutrition plan, being flexible and responsive to your body’s signals can help you maintain balance and well-being.
“Everyone’s experience with their menstrual cycle is different, underscoring the importance of understanding your body’s signals and being attuned to what it needs,” says Moriarty. “Instead of dismissing hunger with thoughts like ‘I’ve eaten enough,’ it’s crucial to recognize and respond to your body’s cues in all aspects, especially when it signals a need for more food. In terms of the menstrual cycle, awareness of your body’s individual responses and the accompanying physiological changes is key.”
Remember, your body is your best guide, and with these tips, you can optimize your performance and wellbeing.
For more advice on managing menstruation and exercise, or matching your nutrition to your cycle, visit the Active Iron athletes & sports professionals page here.
¹https://www.stmarys.ac.uk/news/2019/st-marys-global-study-finds-exercising-during-your-period-makes-you-feel-better. ²Sims. S. et al; High Prevalence of Iron Deficiency Exhibited in Internationally Competitive, Non-Professional Female Endurance Athletes—A Case Study Int J Environ Res Public Health; 2022. ³https://www.nhs.uk/conditions/vitamins-and-minerals/iron/. *Heavy Periods: Overview Informedhealth,org; 2017. **Heavy periods. WOMEN’S HEALTH CONCERN FACT SHEET; 2022. www.womens-health-concern.org
Lexi Moriarty
MS, RDN, CSSD
Lexi Moriarty is a Certified Sports Dietitian and RD with over 14 years experience. A women’s health expert for Active Iron, she specializes in sports nutrition, women’s health, digestive and hormone health, and REDs.
As an avid runner and performance dietitian, she is dedicated to helping clients reach their goals and feel their best both physically and mentally. With over a decade of expertise in the field, she combines a unique blend of sports nutrition, intuitive eating, and evidence-based strategies to educate others on nutrition.
