What sports nutrition is best for women?

For decades, sports science operated under a reductive and fundamentally erroneous assumption: viewing the female athlete as a smaller version of the male athlete. The fueling protocols, hydration strategies, and macronutrient recommendations that still dominate physiology textbooks today were established primarily using male cohorts. Although this approach simplified matters for researchers seeking to avoid the complexity of hormonal fluctuations, it left women to navigate their nutritional preparation largely by trial and error. Yet the question “What sports nutrition is appropriate for women?” demands an answer that goes beyond simple gendered marketing or arbitrary calorie reduction.

Below, we will examine in depth the biochemical mechanisms that distinguish the sexes, the impact of the menstrual cycle on energy needs, and the dangers of chronic energy deficiency. We will also demonstrate why nutritional solutions based on natural ingredients such as fruit purées, brown rice syrup, and plant proteins are the most suitable response to the physiological challenges faced by modern female athletes, whether they are aiming for an Olympic podium or simply exercising for pleasure.

Women’s physiology requires a specific nutritional approach

Today, scientific research and field experience confirm that female physiology has specific metabolic, hormonal, and gastrointestinal characteristics that require a tailored nutritional approach. From managing glycogen stores to the profound impact of ovarian hormones on lipid oxidation, as well as an increased susceptibility to digestive issues during exercise, female athletes must contend with complex “biomachinery.” In this context, the natural nutrition approach championed by brands such as Mulebar takes on its full significance. By prioritizing premium, digestible ingredients free from chemical additives, it addresses not only performance needs but also the demand for superior physiological tolerance.

Sexual dimorphism and energy metabolism: The physiological foundations

To develop a relevant nutrition strategy, it is essential to understand the mechanisms by which the female body produces and uses energy. These fundamental differences, or sexual dimorphism, determine which fuel should be prioritized before, during, and after exercise.

Metabolic flexibility and lipid oxidation

One of the most pronounced distinctions between the sexes lies in the selection of energy sources for exercise. Studies show that women have a greater capacity to oxidize lipids (fats) than carbohydrates (sugars) during endurance exercise. This characteristic is linked to the female hormonal environment, specifically the presence of estrogen. Estradiol promotes the expression of genes involved in lipolysis and the transport of fatty acids to the mitochondria, the cells' energy powerhouses.

In practical terms, this means that at the same exercise intensity (for example, running at 65% of their MAS), a woman will draw more on her intramuscular triglyceride stores (fat droplets stored directly in the muscle) than a man, who will draw on his glycogen (sugar stores) more quickly. This "glycogen sparing" gives women natural "diesel-like" endurance, theoretically allowing them to sustain longer efforts with less dependence on the massive carbohydrate replenishment that often characterizes men's strategies.

However, this increased ability to burn fat should not lead to the strategic mistake of eliminating carbohydrates. On the contrary, it suggests that the type of carbohydrates consumed should be adapted. Rather than saturating the body with high-glycemic-index sugars that cause insulin spikes and block fat oxidation, female athletes benefit more from energy sources released gradually. This is where the formulation of Mulebar products becomes strategically relevant. Using brown rice syrup as the carbohydrate base in our bars, gels and energy compotes offers a moderate absorption profile. Unlike industrial glucose-fructose syrups, brown rice syrup helps maintain stable blood glucose levels, thereby supporting women's natural lipid metabolism while providing the glucose needed by the brain and for high-intensity efforts.

Glycogen management and high intensity

If women burn more fat at low intensity, glycogen management becomes critical as soon as intensity increases. Research indicates that women store proportionally as much glycogen as men, but the key enzyme responsible for its breakdown (glycogen phosphorylase) may be less active under the influence of estrogen.

It has been observed that during high-intensity training, women can conserve up to 50% more glycogen than men. This might seem like an advantage, but it also means a potential difficulty in accessing these sugars quickly during explosive efforts (sprints, steep climbs). This highlights the importance of an external supply of “fast” carbohydrates during critical phases of a race.

Mulebar energy gels, formulated with rice syrup and agave syrup, along with energy fruit purées, provide this immediately available fuel. The presence of natural fructose from fruit (apricot, orange, strawberry) enables the use of intestinal transporters different from those used by glucose, thereby optimizing total carbohydrate absorption without overloading the digestive system, which is often slower in women.

Protein metabolism: myths and reality of muscle mass

Sports nutrition marketing has long perpetuated the myth that protein was reserved for men seeking to “bulk up,” while women were supposed to stick to vegetables to “slim down.” Physiologically, this is absurd. Women also have high protein needs to support tissue repair, hormone synthesis, and immune health.

It is true that women oxidize fewer amino acids (such as leucine) during exercise than men. The female body is therefore more “economical” with muscle protein during exercise, which limits catabolism (muscle self-destruction). However, post-exercise recovery requires particular attention. Because testosterone levels are significantly lower (around 15 to 20 times lower than in men), women do not benefit from the same natural anabolic stimulus. The post-exercise nutritional window, or metabolic window, is therefore crucial for triggering protein synthesis.

Current recommendations place the protein needs of female athletes at between 1.6 and 1.8 g of protein per kg of body weight per day. For a 60 kg female athlete, this represents a daily intake of 96 to 108 g of protein. Reaching this total with a conventional diet can be challenging, especially for those who limit red meat. Incorporating high-quality protein snacks is therefore essential. Mulebar protein bars, made with a blend of pea and soy proteins, meet this need perfectly. This choice of plant proteins is doubly relevant for women:

• Complete profile: The combination of pea/soy ensures a complete profile of essential amino acids, including the BCAAs needed for muscle recovery.

• Digestion and acidity: Plant proteins are less acidifying to the body than dairy proteins (Whey) and do not contain lactose, a common allergen that causes bloating in some people.

Comparison table: sexual dimorphism and nutritional implications

Nutritional chronobiology: adapting nutrition to the menstrual cycle

One of the most significant blind spots in sports nutrition is ignoring monthly hormonal fluctuations. A woman does not have the same hormonal physiology on day 1, day 14, and day 24 of her cycle. These variations affect body temperature, hydration, insulin sensitivity, and mood. Ignoring these phases means training "against the current" half the time.

Follicular phase (Days 1 to 14): the high-performance window

This phase begins on the first day of menstruation and lasts until ovulation. It is characterized by initially low hormone levels (estrogen and progesterone), followed by a gradual rise in estrogen.

• Metabolic profile: During this phase, a woman's physiology most closely resembles a man's in terms of energy metabolism. Insulin sensitivity is optimal, meaning that ingested carbohydrates are efficiently transported to the muscles to be stored as glycogen.

• Nutritional strategy: This is the ideal time to schedule the most intense training sessions (MAS, threshold, strength) and maximize glycogen stores.

  • Carbohydrates: Carbohydrate intake is utilized very effectively. A “carb-loading” strategy will be more effective during this phase preceding a competition.

  • Iron: Menstruation (Days 1–5) causes significant iron loss. It is crucial to increase iron intake. Mulebar bars containing oats (rich in iron) and fruits rich in vitamin C (such as goji berries or lemon) are valuable allies in supporting erythropoiesis (red blood cell formation) from the beginning of the cycle.

Ovulation and the anabolic window

Around day 14, an estrogen surge occurs, often accompanied by a testosterone surge (the only one in the cycle). This is often when maximum strength is at its peak. However, high estrogen levels can also increase ligament laxity (raising the risk of knee injury). Nutritionally, this ability to produce force must be supported by adequate protein intake.

Luteal phase (Days 15 to 28): the physiological challenge

After ovulation, the body produces progesterone, which becomes the dominant hormone, while estrogen levels gradually fall. This is the most challenging phase for performance.

• Insulin resistance and metabolic shift: Insulin sensitivity decreases. The body has more difficulty getting glucose into muscle cells and favors using lipids as fuel. Consuming large quantities of simple sugars during this phase can lead to more pronounced blood sugar fluctuations and “energy crashes.”

• Catabolism and recovery: Progesterone has a catabolic effect: it accelerates the breakdown of amino acids. Protein requirements therefore increase physiologically during this phase to maintain muscle mass. In addition, basal metabolic rate increases (we burn 100 to 300 kcal more per day at rest), which can cause cravings, often wrongly interpreted as gluttony when they actually reflect a genuine energy need.

• Hydration and thermoregulation: Body temperature increases by 0.3 to 0.5°C under the influence of progesterone. This means that the threshold for triggering sweating is delayed: women start sweating later, even though they are already hotter. The risk of heatstroke is increased. Paradoxically, water retention linked to premenstrual syndrome (PMS) causes a feeling of bloating, but the water is trapped in the tissues (edema) and is less available for cooling the blood.

• “Mulebar” strategy for the luteal phase:

  • Prioritize moderate GIs: Avoid pure glucose gels during training. Mulebar energy bars made with oats and fruit are preferable because they smooth the blood glucose curve.

  • Increase protein and healthy fats: This is the time to include bars such as the Mulebar peanut & raspberry bar. Peanuts provide quality protein and fats for satiety and muscle protection, meeting the increase in basal metabolism.

• • Magnesium intake: Essential for reducing abdominal cramps and PMS irritability. The cocoa (rich in magnesium) in the Chocolate/Orange bars and the chocolate protein bars is a functional benefit beyond taste.

The danger of RED-S (Relative Energy Deficiency in Sport) syndrome

A nutritional analysis for women cannot ignore the scourge of RED-S, formerly known as the “Female Athlete Triad.” It occurs when energy intake is insufficient to cover the demands of training and basic vital functions.

The critical threshold is often estimated at around 30 kcal per kg of lean body mass per day. Below this threshold, the body shuts down functions “non-essential” to immediate survival: reproduction (cessation of periods or amenorrhea) and bone density.

The consequences are disastrous: stress fractures, decreased metabolism, depression, and stalled performance.

Many 1,200 kcal/day “weight-loss” diets are a fast track to RED-S. An active woman needs 2,200 to 2,500 kcal, or even 4,000 kcal for a triathlete. 

Macronutrients, the pillars of female performance

Nutritional architecture rests on three pillars: Carbohydrates, Proteins, Fats. While general recommendations (50/30/20) exist, they need to be refined for female athletes.

Carbohydrates: The fuel to modulate

Although women oxidize fat efficiently, carbohydrates remain the limiting factor for high-intensity performance.

• Amount: Requirements range from 5g/kg/day (light training) to 10g/kg/day (pre-marathon loading). Fear of carbohydrates is common among women concerned about their weight, but it is incompatible with performance. Without sufficient carbohydrates, training intensity drops.

• Quality: Choosing brown rice syrup. This is a major differentiating feature of Mulebar products. Most brands use glucose syrup, dextrose, or maltodextrin. These sugars are highly effective but cause sharp blood sugar spikes. Mulebar favors brown rice syrup. This complex sugar, derived from rice fermentation, contains longer carbohydrate chains.

  • Benefit for women: It provides steady energy, preventing reactive hypoglycemia. This is particularly crucial for women who, during the luteal phase, may experience sudden drops in energy if their blood sugar goes on a roller coaster.

  • Optimal blend: In the fruit purées, Mulebar combines this syrup with the fruit's natural sugars (fructose). This glucose/fructose ratio uses two different intestinal transporters (SGLT1 and GLUT5), maximizing energy absorption up to 90g of carbohydrates per hour without digestive overload.

Proteins: building and immunity

We established that an intake of 1.6 to 1.8g/kg is necessary. The quality of the sources is essential.

• The problem with whey (whey protein): Although it is the industry standard, whey often causes problems for women. It can be inflammatory (acne, joint pain) and difficult to digest (bloating) for those who do not tolerate lactose well. In addition, it creates a significant acid load.

• The Mulebar plant-based solution: Using pea and soy proteins offers specific benefits.

  • Peas : Rich in iron (crucial for women) and arginine (promotes blood circulation). Hypoallergenic.

  • Soy : The only complete plant protein equivalent to meat in terms of its amino acid profile. It contains phytoestrogens which, contrary to popular belief, may have a protective and hormone-balancing effect in female athletes (antioxidant).

  • Timing: Consuming 20g of protein within 30 minutes after exercise is imperative to reverse the cortisol curve (the stress, catabolic hormone), which remains elevated for longer in women after endurance exercise.

Lipids: the essential forgotten nutrients

Lipids are often demonized, yet they are the substrate for steroid hormones. A lipid deficiency (<20% of total intake) mechanically leads to a drop in estrogen and progesterone production, directly resulting in the absence of menstruation (amenorrhea) and loss of bone density.

• Fat quality: Unsaturated fatty acids (Omega-3, Omega-9) should be prioritized because they have an anti-inflammatory role. Chronic inflammation (tendinitis) is common among female athletes.

• Mulebar and Functional Lipids: Mulebar bars include ingredients rich in healthy fats, such as cashews, almonds, and sunflower seeds. During ultra-endurance efforts (Ultra-Trail > 6h), these lipids become a fuel of choice, providing twice the energy density of carbohydrates (9 kcal/g versus 4 kcal/g), making it possible to reduce the amounts consumed.

Essential micronutrients: the battle of the invisible

Beyond calories, female athletic performance often comes down to microscopic factors. Three micronutrients deserve particular attention: iron, calcium, and sodium.

Iron: The Achilles’ heel

Iron-deficiency anemia is the most common nutritional condition among female athletes.

• Loss mechanisms:

  1. Menstruation: monthly blood loss.

  2. Impact hemolysis: each foot strike while running compresses the capillaries in the soles of the feet, destroying red blood cells.

  3. Sweating and urination: increased mineral losses.

  4. Hepcidin: this hormone, secreted in response to exercise-induced inflammation, blocks iron absorption in the intestines for 3 to 6 hours after training.

• Consequences: Since iron transports oxygen (via hemoglobin), a deficiency (ferritin < 20 µg/L) causes immediate shortness of breath, an elevated heart rate during exertion, and fatigue.

• Absorption strategy: Eating iron is not enough; it must be absorbed. Plant-based iron is poorly absorbed (2–5%), unless it is paired with vitamin C, which converts ferric iron into absorbable ferrous iron.

  • Mulebar synergy: Mulebar recipes are formulated with this biochemical intelligence. For example, the Chocolate & Orange bar combines plant-based iron from cocoa and oats with vitamin C from orange zest. This natural combination boosts absorption far more effectively than an incorrectly dosed supplement taken at the wrong time.

Calcium and vitamin D: skeletal strength

Peak bone mass is reached at around age 25. After that, it needs to be maintained. Female athletes who participate in weight-supported sports (cycling, running) or experience amenorrhea are at risk of osteopenia, a decrease in bone density that is less severe than osteoporosis.

• Needs: 1,000 to 1,200 mg/day.

• Vitamin D: Essential for calcium absorption. A large part of the population is deficient, especially in winter. Mulebar Red Berry hydration drinks or citrus flavors are enriched with Vitamin D (3.1µg/serving), a rare initiative on the market that contributes to the athlete's bone and immune health.

Sodium and Hydration: The Risk of Hyponatremia

Women often have a lighter build and less muscle mass (which contains water) than men. Statistically, they are more likely to experience dilutional hyponatremia (drinking too much plain water without salts), which can be fatal (cerebral edema).

• Signs: Headaches, confusion, nausea (often mistaken for dehydration or heatstroke).

• Solution: Never drink plain water during exercise lasting more than 1.5 hours. Always include electrolytes. The Mulebar citrus hydration drink or red berry flavor provides the 4 major salts (Sodium, Potassium, Magnesium, Calcium) to maintain blood osmolarity without overloading the stomach. The mildly sweet taste encourages regular consumption without becoming sickening, a key factor for women's hydration, which is often disrupted by overly chemical-tasting flavors.

Digestion and the Microbiome: The Advantage of 100% Natural Ingredients

Why do women suffer more from digestive problems during exercise? Statistics show that female runners are twice as likely as male runners to experience intestinal pain, bloating, and exercise-induced diarrhea.

Digestive Anatomy and Physiology

• Mechanical: The geometry of the female pelvis and the proximity of the reproductive and digestive organs create an area of mechanical "conflict" during repeated impacts.

• Hormonal: Prostaglandins released during menstruation stimulate contractions of the uterus as well as those of the intestines, speeding up transit (diarrhea). During the luteal phase, progesterone has the opposite effect: it relaxes smooth muscles, slowing gastric emptying (nausea, heaviness).

• Ischemia: During exercise, blood leaves the digestive tract for the muscles (-80% blood flow). The intestinal barrier becomes permeable—a "Leaky Gut"—allowing toxins and poorly digested food fragments to pass through, triggering inflammation and pain.

The Crucial Importance of Natural Ingredients

This is where Mulebar's 100% natural positioning is not just a marketing argument, but a "therapeutic" response.

• Avoid the chemical cocktail: The colorants, preservatives (potassium sorbate), artificial flavors, and intense sweeteners (sucralose, aspartame) found in low-end gels are major irritants for an intestinal lining already weakened by ischemia. They alter osmolarity and ferment.

• The Mulebar philosophy: By using only natural ingredients (fruit, plant and fruit syrups, cereals, seeds), Mulebar drastically reduces the xenobiotic load (foreign to the body). The many customer reviews overwhelmingly confirm this high digestibility: "No stomach aches", "Easy digestion", "intestinal comfort".

• Energy compote as an alternative: For many women, the viscous, highly concentrated texture of traditional gels triggers a gag reflex, especially toward the end of a race. Mulebar energy compotes offer a "real food" texture that is smoother, fruitier, and less aggressively sweet, making it much easier to digest.

Nutrition and motherhood

Sport does not stop with motherhood. More and more women maintain an appropriate level of physical activity during pregnancy and breastfeeding. Nutrition must then serve two organisms: mother and child.

Pregnancy: absolute safety required

During pregnancy, the placental barrier allows nutrients and toxins to pass through. The consumption of "chemical" sports nutrition products packed with synthetic caffeine, taurine, or sweeteners should be avoided.

• Mulebar as a healthy snack: Since Mulebar products are organic and additive-free, they are perfectly safe for pregnant women (with the exception of gels containing added caffeine).

• Managing hypoglycemia: Pregnant women are prone to hypoglycemia. Having a compote or a Mulebar bar in your bag allows you to "raise your blood sugar" healthily with quality carbohydrates and fruit, rather than with an industrial chocolate bar saturated with saturated fats. Compotes also provide gentle fiber to regulate bowel movements, which are often slowed during pregnancy.

Breastfeeding and galactogenesis

Breastfeeding requires an additional energy expenditure of 500 kcal/day.

• Lactogenic ingredients: Certain foods are reputed to promote lactation. Oats and almonds, which are the basic ingredients in Mulebar bars, are among them. The essential fatty acids in nuts also enhance the lipid quality of breast milk.

• Practicality: For an active mother, the bar is a convenient format for eating with one hand while breastfeeding or pushing a stroller, ensuring she does not neglect her own nutrition in favor of the baby’s.

Nutrition and menopause

Perimenopause and menopause profoundly affect female physiology, and these hormonal changes have a direct impact on sports nutrition.

The gradual decline in estrogen changes the way the body uses energy: fat oxidation decreases, insulin sensitivity is reduced, and there is a greater tendency to store carbohydrates as fat. As a result, maintaining performance requires adjusting intake, particularly by favoring moderate-glycemic-index carbohydrates, high-quality protein (20 to 30 g after exercise to limit muscle loss), and anti-inflammatory fats.

The drop in estrogen also increases oxidative stress and bone fragility, reinforcing the importance of micronutrients such as magnesium, vitamin D, calcium, and omega-3s.

Finally, since thermoregulation is less efficient and recovery is slower, more structured hydration and appropriate electrolyte intake become key levers for continuing to perform comfortably and confidently.

Practical protocols

Here’s how to incorporate this knowledge into fueling plans, compared with standard practices.

Mulebar fueling protocols by profile

Profile A: The marathon runner (4:00 target)

• Challenge: The wall at the 30th km (glycogen depletion) + digestive issues.

• Before (Day -3): Carbohydrate loading (pasta, rice).

• Race morning: Easily digestible breakfast (sports cake or sourdough bread + honey). 1 hour before: 1/2 Mulebar Pineapple-Coconut Bar (sustained energy without an insulin spike).

• During the race:

  • Km 10: Mulebar Lemon Ginger Gel (ginger helps prevent early nausea, and the resealable cap allows it to be consumed in 3 portions over 2 km).

  • Km 20: Mulebar Apricot Compote (a change in texture, freshness, and a break from the sweetness of sugar).

  • Km 30: Mulebar Salted Caramel Gel (the salt helps prevent cramps, while the sugar re-energizes the brain).

  • Hydration: 500 ml/h of Mulebar electrolyte drink for sodium.

Profile B: The triathlete (Olympic distance M)

• Challenge: Back-to-back activity and digestion in an aerodynamic position on the bike.

• Cycling (40 km): It’s time to eat solid food. 1 Mulebar Raspberry Peanut Bar (protein + salt + fat) cut into small pieces. Chewing helps reduce stress.

• Running (10 km): Switch to liquids. 1 Coffee Caffeine Gel at km 5 for the final “kick”.

Profile C: The yoga / fitness / wellness practitioner

• Challenge: Muscle recovery and tone without excess calories.

• After training: vegan cocoa protein bar or strawberry almond. Provides the 10 g of protein needed to tone muscles without heaviness. Perfect 4 p.m. snack at the office.

The story of the cap on Mulebar gels

Mulebar gels are the only ones to offer a truly resealable tube with a cap like those on toothpaste tubes. This meets a need expressed by female athletes who repeatedly told us at trade shows that the gels on the market, as well as our Mulebar gels in soft sachets, were not suited to their needs because they were too large and too sweet to consume all at once. Offering a cap makes it possible to consume them in portions, completely changing the nutritional approach by avoiding a carbohydrate spike and providing a more gradual supply that prevents the “yo-yo” effect. This approach also applies to men.

As the tube does not leak once finished (there is always a little gel left inside), there is no reason to “dispose of it” in nature, as some athletes unfortunately do with other brands. Just look along roads and trails. Finally, Mulebar gel tubes are reusable. After rinsing them with hot water, they can be refilled using their eco-refills. Ecological and economical!

High standards in the service of performance

Sports nutrition for women is not just about pink packaging. It is a precision science that must respect a cyclical physiology, a unique fat metabolism, and increased digestive sensitivity.

By analyzing the market and physiology, it becomes clear that the “chemical” approach taken by some brands has limitations for female consumers (digestive disorders, unsuitable ingredients). The natural approach championed by Mulebar is the most consistent response to the needs identified:

• Maximum digestibility: Thanks to the absence of preservatives and the use of premium 100% natural ingredients.
• Energy stability: Thanks to moderate glycemic indexes (agave syrup, oats) that respect the female lipid metabolism.
• Overall health: Thanks to the supply of real micronutrients (Iron, Vitamin C, Magnesium) from fruit and nuts, rather than synthetic powders.

For the athletic woman, choosing her nutrition is an act of respect for her body. It means refusing to treat it like a standardized machine and recognizing its complexity and unique strength. With the right strategies and fuel, every phase of the cycle, every mile, and every challenge becomes an opportunity for performance.