Women who train seriously have become increasingly selective about what they fuel their performance with. Macros, timing, hydration, recovery nutrition — all of it gets scrutinised. But there are two areas that get significantly less attention despite having real relevance to how a woman feels during training and throughout her cycle: what her period products are made of, and what her gut microbiome is doing.
Neither topic is fringe. Both have practical implications for performance, comfort, and day-to-day wellbeing.
What Goes Into Your Period Underwear
The period underwear market has expanded quickly, and the environmental case for switching from disposables is well established. A reusable pair of period pants worn for several years generates a fraction of the waste produced by a monthly supply of single-use products. That argument has been made convincingly and most active women are already aware of it.
What gets less attention is the material composition question. Conventional textiles, including many used in activewear and underwear, are processed with dyes, finishing chemicals, antimicrobial treatments, and synthetic coatings. Some of these residues remain in the fabric. For period underwear worn directly against sensitive tissue during menstruation, that material profile matters differently than it might for, say, a running jacket.
Demand for non toxic period underwear has grown in response to this awareness. Saalt, which focuses specifically on this category, uses materials chosen with skin safety in mind. For women who already read the ingredients panel on supplements and pay attention to what they eat, extending that scrutiny to what they wear is a consistent extension of the same thinking.
For athletes training through their cycle, comfort and confidence during movement is non-negotiable. Period underwear that performs reliably and is made with materials you can trust is simply better kit, the same logic applied to choosing shoes or a sports bra.
What Your Gut Is Doing During Your Cycle
The connection between gut health and menstrual symptoms is getting more research attention, and for good reason. Progesterone, which dominates the luteal phase in the lead-up to menstruation, slows gut motility. This is why bloating, constipation, and digestive discomfort are so common in the days before a period. It is not a mystery; it is physiology.
For women in heavy training blocks, this timing can create a compounding problem. Hard training already places demands on digestion, particularly when nutrition timing is tight around sessions. Add progesterone-driven gut slowdown and the result can be real disruption to how you absorb and use the food you are eating.
The gut microbiome also plays a role in oestrogen metabolism. A healthy, balanced microbiome helps process and recycle oestrogen efficiently through a process involving an enzyme complex called the estrobolome. When gut diversity is compromised, that process can become dysregulated, which has downstream effects on hormone balance.
A well-formulated gut health supplement containing clinically studied probiotic strains can support microbial diversity and help maintain a more stable gut environment across the cycle. Evogen Nutrition’s Probiotic DR30 is formulated with this in mind, using strains selected for their relevance to digestive function and immune support. For women managing demanding training loads alongside monthly hormonal shifts, keeping the gut functioning well is not an optional extra.
Putting It Together in Practice
The practical approach is straightforward. For period products, it comes down to choosing options made with material transparency you can verify. If you already invest in quality nutrition and training equipment, extending that standard to what you wear during your period is consistent. Look for brands that disclose fabric composition clearly and prioritise skin-safe materials.
For gut health, the goal is consistency. A probiotic supplement taken daily rather than reactively when symptoms appear builds a more stable microbial environment over time. Pairing supplementation with dietary fibre from whole grains, legumes, fruits, and vegetables supports the gut bacteria you are trying to cultivate. Fermented foods like yoghurt, kefir, and kimchi add additional live cultures and can complement a supplement approach.
Hydration, as ever, matters for both. Adequate fluid intake supports digestive motility and helps the body move things along during the phases where progesterone makes that harder.
Neither of these areas requires a complete overhaul of how you train or eat. They are refinements, the kind that experienced athletes make when the big-ticket factors are already well managed and the marginal gains come from looking at what was previously overlooked.
Frequently Asked Questions
What makes period underwear non-toxic? Non-toxic period underwear is made with materials that avoid chemicals of concern such as PFAS, formaldehyde-releasing finishes, synthetic antimicrobial treatments, and residual dyes that may irritate sensitive skin. Brands focused on this category typically disclose their fabric composition and may carry third-party certifications related to textile safety.
Is period underwear suitable for training and sport? Yes. Many brands design period underwear specifically for movement, with moisture-wicking fabrics, secure fits, and absorbency layers that function during physical activity. Active-specific styles are cut to accommodate high-intensity movement without shifting or leaking.
How does the menstrual cycle affect gut health? Progesterone during the luteal phase slows gut motility, which can lead to bloating, constipation, and digestive discomfort. Oestrogen also influences the gut microbiome through the estrobolome, a group of gut bacteria involved in oestrogen metabolism. Supporting microbiome diversity can help manage these cyclical digestive changes.
What should I look for in a probiotic supplement for women? Look for strains with clinical research behind them, a delivery mechanism that protects bacteria through the stomach acid environment, a stated colony-forming unit count, and transparency around storage requirements. Products formulated with multiple complementary strains tend to offer broader support than single-strain options.
Can a probiotic help with PMS symptoms? Some research suggests that gut health interventions, including probiotic supplementation, may support hormone balance and reduce inflammatory responses associated with PMS. The gut-hormone axis is an active area of research. While probiotics are not a standalone treatment for PMS, supporting gut health as part of a wider approach to nutrition and lifestyle can be a useful tool.
How long does it take for a probiotic supplement to show effects? Most people notice changes in digestive comfort within two to four weeks of consistent use. Broader effects on microbiome diversity and hormone-related symptoms may take longer, typically one to three menstrual cycles. Consistency matters significantly more than timing relative to cycle phase.
How often should I replace period underwear? Well-maintained period underwear typically lasts between two and five years depending on use frequency and washing habits. Washing in cold water on a gentle cycle and air drying rather than tumble drying extends lifespan. When absorbency noticeably declines, it is time to replace.
