Athletes routinely place extraordinary demands on their bodies. Each sprint, lift, jump, or prolonged training session stresses muscle tissue, connective structures, and metabolic systems in ways most people never experience. Skeletal muscle is not merely about strength or appearance. It is central to movement, joint stability, metabolic regulation, and the body’s ability to recover and adapt to training over time.
Training provides the stimulus for muscles to become stronger and more resilient, but protein provides the raw materials that make this adaptation possible.
Without adequate protein, the body struggles to repair exercise-induced damage, maintain lean tissue, and fully adapt, particularly during periods of heavy training or reduced energy intake(1).
Although the basic principles of muscle biology apply to everyone, female athletes experience distinct physiological contexts. Hormonal fluctuations across the menstrual cycle, the use of hormonal contraceptives, and transitions such as menopause naturally raise questions about whether women require different protein strategies. Historically, these questions have been difficult to answer, in part because sports nutrition research has focused predominantly on male participants(2).
As a result, guidance for female athletes has often relied more on assumption than evidence.
Figure: Hormonal fluctuations across the menstrual cycle (~21-35 days) include the follicular and luteal phases. Estrogen (blue) peaks prior to ovulation, triggered by a surge in luteinizing hormone (green). Progesterone (yellow) rises post-ovulation. Menstruation begins on day 1 and typically lasts 5-7 days. Note the wide variability in the phase lengths (adapted from D’Souza et al 2025)
What follows is a clear, evidence-informed look at what protein actually does for female athletes and where common concerns are overstated.
Together, these processes are referred to as muscle protein turnover. When synthesis exceeds breakdown, muscle tissue repairs and strengthens. When breakdown predominates, muscle mass declines(1).
Resistance exercise such as weight training or bodyweight exercise is the primary signal that shifts this balance toward growth and repair. Dietary protein supports this response by supplying amino acids, the fundamental components of muscle tissue.
One amino acid in particular, leucine, plays a key signaling role, helping initiate muscle protein synthesis after eating(3).
Without sufficient protein available, the body receives the signal to adapt but lacks the necessary materials to fully execute that adaptation.
A common misconception is that more protein at a single meal automatically leads to more muscle. In reality, muscle tissue has a limited capacity to respond to protein at any given time.
After protein is consumed, muscle protein synthesis rises for roughly two hours and then returns toward baseline even if amino acids remain available in the bloodstream(3).
Beyond a certain point, additional protein does not further increase muscle building and is instead oxidized or stored. Research consistently shows that a per-meal intake of approximately 0.3 grams of protein per kilogram of body weight, roughly 25 to 35 grams per meal for most women, maximally stimulates muscle protein synthesis(3).
Consuming substantially more than this in one sitting does not confer additional benefit for muscle growth.
While total daily protein intake is important, how that protein is distributed across the day also matters.
Consuming most protein at a single meal, such as dinner, leaves long stretches of the day when muscle protein synthesis is under-stimulated.
Studies show that spreading protein intake evenly across meals roughly every three to four hours supports greater muscle repair and adaptation than uneven intake patterns(4).
Breakfast, lunch, and dinner all contribute meaningfully to muscle health.
In practical terms, distributing protein allows the body to repeatedly activate muscle-building pathways rather than relying on a single, oversized signal.
For most female athletes, a daily protein intake of 1.4 to 1.6 grams per kilogram of body weight (approximately 0.6 to 0.7 grams per pound) effectively supports training adaptation, recovery, and lean mass preservation(1,5).
Higher intakes up to around 2.0 grams per kilogram per day may be appropriate during periods of heavy training, intentional weight loss, or reduced energy availability, when preserving muscle becomes more challenging(5).
Hormone levels fluctuate across the menstrual cycle, and it is reasonable to wonder whether protein requirements vary from week to week. Early research suggested slightly higher protein breakdown during the luteal phase, but the absolute difference amounts to only 3–5 grams of protein per day, a nutritionally trivial amount(6).
More recent, carefully controlled studies show no meaningful differences in muscle protein synthesis or breakdown across menstrual cycle phases and no evidence that protein intake must be adjusted based on cycle timing(6,7).
Rather than micromanaging intake by cycle phase, female athletes are best served by focusing on consistency, which means meeting daily protein targets, distributing intake across meals, and responding naturally to appetite changes that occur throughout the cycle.
Hormonal contraceptives alter endogenous hormone patterns, but current evidence indicates that their use does not meaningfully affect muscle protein synthesis or overall protein requirements(6).
While different formulations may have subtle physiological effects, there is no strong evidence to support adjusting protein intake based on contraceptive use alone.
During perimenopause and menopause, estrogen levels decline and age-related muscle loss often accelerates. This has led to claims that menopausal women require substantially higher protein intakes.
However, available evidence suggests that muscle loss during this life stage is driven primarily by aging and reduced muscle loading, rather than estrogen deficiency itself(5).
Estrogen-based hormone therapy does not prevent muscle loss, and physically active women tend to retain greater muscle mass and responsiveness to protein than sedentary peers of the same age.
For menopausal athletes, the fundamentals remain unchanged: regular resistance training, adequate protein intake (around 1.6 g/kg/day), and long-term consistency.
Periods of low energy availability whether intentional or accidental are common in certain sports. When calorie intake drops, muscle protein synthesis is suppressed and muscle breakdown increases(1).
Protein intakes above 2.0 g/kg/day can help mitigate muscle loss during calorie restriction, but training stimulus remains the primary determinant of whether muscle is retained(7).
Resistance training produces large and prolonged increases in muscle protein synthesis. Endurance exercise also stimulates muscle adaptation particularly within mitochondria, but the overall anabolic signal is smaller(1).
Endurance training increases amino acid oxidation, especially during long or intense sessions, which may justify modestly higher protein intakes for athletes with high training volumes or limited carbohydrate availability(1).
Even so, most athletes across sport types perform well within standard protein recommendations when intake is adequate and evenly distributed.
Plant-based diets are increasingly common among athletes. While individual plant proteins may be lower in certain essential amino acids or less digestible than animal proteins, this does not preclude effective muscle support.
They can achieve muscle responses comparable to those of omnivorous athletes(8).
A modest increase in total intake on the order of 10 percent may help compensate for differences in protein quality.
Figure: Recommended protein intake to support exercise-induced muscle adaptations in female athletes. Resistance exercise is the primary driver of positive muscle mass adaptations (growth, strength, retention), while dietary protein serves a supportive role. (adapted from D’Souza et al 2025)
Despite persistent myths and gaps in female-specific research, the evidence points to a clear conclusion: consistency matters more than complexity.
Female athletes do not require dramatically different protein strategies based solely on hormones, cycle phase, or contraceptive use. Steady protein intake, thoughtful meal timing, and regular strength training form the foundation of muscle health across sports, diets, and life stages.
Protein is not a shortcut or a cure-all, but when combined with appropriate training, it provides the body with exactly what it needs to recover, adapt, and perform over the long term.
A simple way to ensure you're hitting your daily protein goals, protein shakes are a great way to do it. Whether you like WHEY-based protein or VEGAN, DAIRY-FREE options, STEEL has a variety of delicious flavors to choose from.
References:
Phillips SM, Van Loon LJC. Dietary protein for athletes: From requirements to optimum adaptation. J Sports Sci. 2011;29(suppl 1):S29–S38. doi:10.1080/02640414.2011.619204
Smith GI, Reeds DN, Hall AM, et al. Sexually dimorphic responses of skeletal muscle protein synthesis to exercise and nutrition. J Appl Physiol. 2009;106(5):1692–1701. doi:10.1152/japplphysiol.91347.2008
Moore DR. Maximizing post-exercise anabolism: The case for relative protein intakes. Front Nutr. 2019;6:147. doi:10.3389/fnut.2019.00147
Areta JL, Burke LM, Ross ML, et al. Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. J Physiol. 2013;591(9):2319–2331. doi:10.1113/jphysiol.2012.244897
Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training–induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384. doi:10.1136/bjsports-2017-097608
D’Souza RF, Colenso-Semple LM, Willoughby DS, et al. The influence of the menstrual cycle on exercise metabolism and muscle protein turnover. Sports Med. 2023;53(2):229–245. doi:10.1007/s40279-022-01775-2
Colenso-Semple LM, Earp JE, D’Souza RF, et al. No effect of menstrual cycle phase on muscle protein synthesis following resistance exercise in eumenorrheic women. J Physiol. 2025;603(4):897–910. doi:10.1113/JP284321
Nichele P, Vesanto K, Phillips SM. Plant-based diets and skeletal muscle health in athletes. Nutrients. 2022;14(11):2311. doi:10.3390/nu14112311
