Understanding performance supplements for women

While men and women share the same fundamental nutritional needs, there are often important differences to consider when it comes to performance supplements.

Men and women are distinctly different, not only physically in terms of their weight, height and body composition, but also in their physiology and biology, particularly the ways their hormonal (endocrine) systems function, along with their metabolisms.

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How men and women differ

Importantly, women generally weigh less than men, which means a dose of a potent compound or ingredient may need to differ for men and women.

In addition, women metabolise certain compounds differently than men due to differences in their body composition, and digestion and absorption rates¹ – women have a slightly longer colon (roughly 10cm) than men, a slower gastric emptying rate, a lower gut pH (making it less acidic), and different gut flora composition.

For example, men and women metabolise caffeine at different rates². Men typically experience a greater effect within a shorter time than women, but women tend to clear this substance more slowly, which means the effect may last longer.

As such, while men and women generally take the same performance-boosting supplements, it is often the dosage and formulation that can vary slightly, especially when it comes to products with stimulants like caffeine.

Interestingly, differences in hormone profiles, particularly muscle-building hormones like testosterone, mean women can sometimes get a bigger benefit from supplementing with certain products.

However, misconceptions about certain supplements mean many women ignore potentially beneficial products because they are marketed mainly at men or packaged to appeal more to a male audience.

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Beta-alanine

Beta-alanine is an amino acid that increases a substance in muscle (known as carnosine) that reduces oxidative stress, and helps stabilise muscle pH, which can help to extend time to fatigue, which improves performance.

However, this is one product that flies under a woman’s radar, despite its potential benefits for hard-training or competitive female athletes.

The standard recommended daily dose of beta-alanine for performance enhancement is 4-6g for 2-4 weeks (or longer), typically divided into smaller doses throughout the day.

While women might have lower baseline carnosine levels and, as such, could potentially respond more efficiently to beta-alanine, the general dosage guidelines don’t significantly differ between men and women.

Caffeine

As mentioned, women metabolise caffeine differently from men, but when used correctly, it is a proven performance-enhancing aid. Caffeine stimulates the central nervous system, reducing perception of fatigue, and also increases the release of adrenalin, and may spare muscle glycogen².

For both men and women, the widely accepted ergogenic dose of caffeine for performance enhancement is typically 3-6mg/kg, taken about 30-90 minutes before exercise.

While the general principles of caffeine use for performance enhancement apply to both men and women, women should consider their individual physiological factors, especially hormonal status and body weight, when determining their optimal dosage and timing.

Zinc + Magnesium Aspartate (ZMA)

ZMA is generally considered a testosterone booster, which means it is predominantly used by men. However, women can potentially derive a performance benefit as well due to their ability to regulate hormones, improve sleep quality, and support muscle recovery.

By supporting optimal hormone levels, ZMA can enhance strength, power, and muscle growth without inducing masculinising effects. The combination of zinc, magnesium aspartate and vitamin B6 also helps to maintain normal muscle function and reduce tiredness and fatigue.

While the timing of ZMA intake is consistent for both men and women (before bed, on an empty stomach, away from calcium), the typical dosages differ, with men generally taking a slightly higher dose to reflect their higher baseline needs for zinc and magnesium.

As such, women may need to take a smaller daily dose, especially if they get zinc and magnesium from other supplements.

Creatine

Creatine is possibly the most effective supplement for improved performance, for both men and women³. It is a natural substance found in the body that plays an important role in energy production, providing the immediate energy required for short, intense muscle contractions.

Numerous scientific studies have demonstrated the safety and effectiveness of creatine supplements, showing increases in strength, power, lean body mass, endurance and recovery. In fact, research suggests that women may get a bigger benefit from adding a creatine supplement to their daily routine, with value at every stage in a woman’s life, including menopause⁴.

These outsized female-specific benefits stem from the fact that women typically have 70–80% less creatine stored in their bodies compared to men³. Hormonal fluctuations during menstruation, pregnancy, postpartum, and menopause can also affect creatine levels.

These hormonal changes can result in muscle loss and reduced bone density, which is exacerbated by age-related muscle loss known as sarcopenia⁵.

A landmark study⁶ on the benefits of creatine supplements throughout a woman’s lifecycle confirmed that, when combined with resistance training, “creatine further augments body composition and bone mineral density, particularly in post-menopausal females.”

Post-menopausal women who took higher doses (0.3g·kg^-1·d^-1) also experienced benefits by developing more muscle and improving muscle function when taken alongside resistance training, which led to favourable effects on bone density.

Protein

Protein plays a crucial role in maintaining overall health and supporting athletic performance, especially for females in older age. As women age, they face physiological changes like sarcopenia (age-related muscle loss) and anabolic resistance (reduced muscle response to protein), which necessitate a higher protein intake to preserve muscle, strength, and vitality.

Neglecting your protein intake is not only detrimental to your ability to recover properly and maintain optimal health, but it also negatively impacts on your performance and metabolism.

A higher protein intake preserves muscle during training, and supports muscle repair and growth, which is beneficial for your resting or basal metabolic rate (BMR).

Protein is also a crucial component of bone tissue. Sufficient protein intake contributes to better bone mineral density, reducing the risk of osteoporosis and fractures, which is especially important for women post-menopause.

While the general Recommended Dietary Allowance (RDA) for protein is 0.8g/kg/day, this is often insufficient for active and older females.

For women who are physically active, including athletes, and those over 50, recommendations typically range from 1.2-2.0g/kg/day.

NO boosters

L-citrulline and L-arginine are popular in pre-workout supplements because they increase nitric oxide (NO) production, which helps dilate blood vessels, improving blood flow, oxygen, and nutrient delivery to muscles. These benefits mean more energy during workouts and quicker recovery.

While the general mechanisms apply to both men and women, there are some subtle physiological differences between the sexes that could theoretically impact the efficacy of L-citrulline and L-arginine, such as the potential impact that oestrogen has on baseline levels.

However, current research doesn’t provide strong, definitive evidence for distinct dosage or timing guidelines based purely on sex for performance enhancement. The general recommendations for effective doses and timing of L-citrulline and L-arginine apply to both.

Electrolytes

When we sweat during exercise, we lose important minerals known as electrolytes, including sodium, chloride, potassium, magnesium, calcium, and phosphorus.

Our body needs these mineral salts to support hydration and numerous other bodily functions, including muscle contractions⁷.

Crucially, these mineral salts help regulate the amount of water inside and outside our cells, which is vital for fluid balance. This is important for proper muscle and nerve function⁷, especially during physical activity.

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Female-specific considerations

Women, especially those who menstruate, are at a higher risk of iron deficiency anaemia due to blood loss. Iron is crucial for oxygen transport, and deficiency can significantly impair athletic performance, causing fatigue and weakness.

Therefore, an iron supplement may prove critical for female athletes, but your specific requirements should be determined in conjunction with a medical professional.

Furthermore, women tend to lose bone density at a faster rate than men, particularly after menopause. As such, adequate calcium and vitamin D are vital for bone health and muscle function.

Incorporating these supplements into a well-rounded fitness regimen can help women achieve their performance goals. Always remember that achieving your results will require consistent weight training, proper nutrition, and adequate rest, coupled with supplements.

References:

1. Monrroy H, Borghi G, Pribic T, Galan C, Nieto A, Amigo N, Accarino A, Correig X, Azpiroz F. Biological Response to Meal Ingestion: Gender Differences. Nutrients. 2019 Mar 26;11(3):702. doi: 10.3390/nu11030702. PMID: 30917512; PMCID: PMC6471145.
2. Temple JL, Ziegler AM. Gender Differences in Subjective and Physiological Responses to Caffeine and the Role of Steroid Hormones. J Caffeine Res. 2011 Mar;1(1):41-48. doi: 10.1089/jcr.2011.0005. PMID: 24761262; PMCID: PMC3621315.
3. Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017 Jun 13;14:18. doi: 10.1186/s12970-017-0173-z. PMID: 28615996; PMCID: PMC5469049.
4. Smith-Ryan AE, Cabre HE, Eckerson JM, Candow DG. Creatine Supplementation in Women’s Health: A Lifespan Perspective. Nutrients. 2021 Mar 8;13(3):877. doi: 10.3390/nu13030877. PMID: 33800439; PMCID: PMC7998865.
5. Volpi E, Nazemi R, Fujita S. Muscle tissue changes with aging. Curr Opin Clin Nutr Metab Care. 2004 Jul;7(4):405-10. doi: 10.1097/01.mco.0000134362.76653.b2. PMID: 15192443; PMCID: PMC2804956.
6. Smith-Ryan AE, Cabre HE, Eckerson JM, Candow DG. Creatine Supplementation in Women’s Health: A Lifespan Perspective. Nutrients. 2021 Mar 8;13(3):877. doi: 10.3390/nu13030877. PMID: 33800439; PMCID: PMC7998865.
7. Shrimanker I, Bhattarai S. Electrolytes. 2023 Jul 24. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 31082167.