Hormones & your cycle
What's happening in your body — and why it matters for how you train, recover, and protect yourself from injury.
A NOTE BEFORE YOU READ
Research on the menstrual cycle and its impact on athletic performance, injury risk, and recovery is still evolving. Many studies in this space are limited by small sample sizes, inconsistent methodology, and a historical underrepresentation of female athletes in sports science research.
What you'll find on this page is an up-to-date assessment of what the current evidence suggests — not definitive conclusions. The goal is to give you a starting point for understanding your own body, not a rulebook. As the research grows, so will this page.
YOUR CYCLE IS DATA — NOT AN EXCUSE
One of the most underutilized tools in female athlete performance and recovery is the menstrual cycle itself. Most training and rehab programs don't account for hormonal fluctuations at all — and that's a significant gap.
This page isn't about limiting what you do based on your cycle. It's about understanding your body well enough to work with it rather than against it.
Underlined text throughout this page links directly to the research behind it.
The Four Phases — What's Actually Happening
The menstrual cycle typically spans 26 to 32 days and can be divided into the early follicular, late follicular, ovulation, and luteal phases. Hormonal fluctuations across these phases influence energy metabolism, thermoregulation, neuromuscular activation, and psychological wellbeing. Read the research →
Here's what that means in plain terms for a female athlete:
FOLLICULAR PHASE (DAYS 1 — 14, APPROXIMATELY)
Estrogen is rising. Research suggests the late follicular phase may support enhanced dynamic strength and neuromuscular performance — driven by high estrogen and relatively low progesterone. Many athletes report feeling stronger and more energized during this phase. That said, individual responses vary significantly — this is a general pattern, not a universal rule.
LUTEAL PHASE (DAYS 14 — 28, APPROXIMATELY)
Progesterone dominates. This phase can impact recovery rate, reduce performance at higher intensities, and affect mood, energy, and thermoregulation. Research shows plasma volume can drop by as much as 8% during the mid-luteal phase — meaning thicker blood and potentially greater dehydration risk for some athletes. That said, peer-reviewed research notes these hormonal effects on fluid balance don't consistently translate to measurable changes in sweat rate or dehydration during exercise — individual variation is significant. The late luteal phase — just before menstruation — is when many athletes experience the most significant physical and psychological symptoms.
MENSTRUATION (DAYS 1 — 5)
The cycle resets — estrogen and progesterone are both at their lowest. Many athletes experience physical symptoms like cramping, fatigue, and bloating that can affect how training feels. Research found that 20% of athletes modify their training routines or use analgesics during this phase to manage symptoms — which is a real and valid response to what the body is going through. That said, the low hormone environment itself isn't necessarily performance-limiting. Some athletes find that once symptoms are managed, this phase supports lighter, intentional recovery work well. As always, individual experience is the best guide.
OVULATION (AROUND DAY 14)
Estrogen and testosterone peak — and many athletes report feeling at their physical best during this window. Energy tends to be high, motivation strong, and performance often feels most accessible. However, research has linked the pre-ovulatory phase to a higher incidence of non-contact ACL injuries — with estrogen's effects on ligament laxity considered a contributing factor. This doesn't mean you shouldn't train hard during this phase. It means staying mindful of warmup quality, landing mechanics, and movement control — especially in cutting and pivoting sports.
— REFLECTION
When I tore my ACL the second time, I was in my pre-ovulatory phase. At the time, I wasn't tracking my cycle — but being in a contact sport, I became very attuned to the physical changes I felt across different phases. The shifts in energy, joint comfort, and mood were hard to ignore once I started paying attention.
But let me be honest: as much as the research encourages cycle tracking, the reality of being a student athlete is much harder. The nature of our sport means we compete and train hard on whatever day the schedule demands — not whatever day our hormones cooperate.
The purpose of this page isn't to have you train in strict accordance with your cycle. It's so that on the hard days — the days you're competing while cramping, or pushing through a luteal phase when everything feels heavier — you're that much more mindful and intentional. Maybe that looks like modifying your warm-up. Maybe it's being more deliberate about fueling, hydrating, or sleeping around a tough training block. Maybe it's just knowing why your body feels different today.
The goal is awareness — not hyper-vigilance. Not another thing to stress about. Just one more tool that helps you attack your recovery harder and show up more intentionally for your body.
Why This Matters for ACL Injury Risk
Female athletes tear their ACL at significantly higher rates than male athletes in the same sports — and the menstrual cycle is emerging as a meaningful piece of that puzzle.
Research has shown that ACL injury risk is greater during the preovulatory phase of the menstrual cycle — with a higher incidence of non-contact ACL injuries during the days leading up to ovulation, when estrogen and relaxin levels are at their peak. Dr. Sterett, a board-certified orthopedic surgeon and sports medicine specialist, notes that hormonal changes during this window affect ligament laxity and neuromuscular control — two factors directly involved in ACL injury mechanics.
The sports world is taking notice. In April 2025, FIFA funded a groundbreaking study at Kingston University to investigate whether hormonal fluctuations during the menstrual cycle could be contributing to an alarming rise in career-threatening knee injuries in women's soccer — specifically tracking estrogen and progesterone levels previously linked to increased ligament laxity and decreased neuromuscular reaction times. Read the ESPN report →
This research is still developing — a causal relationship has not yet been definitively established. But the question is being taken seriously at the highest levels of sport science. And for female athletes navigating cutting, pivoting, and contact sports, it's worth knowing.
Menstrual cycle tracking can also help identify the 50% of female athletes who experience menstrual disorders — which are often linked to relative energy deficiency, poor recovery, and overtraining. Irregular or absent periods are not just a side effect of training hard. They're a signal that something in the system is off — with real consequences for bone health, injury risk, and long-term athletic longevity.
For a deeper dive into energy deficiency and hormonal health, visit the RED-S & The Female Athlete Triad page →
What You Can Actually Do With This
This isn't about training around your cycle or using it as a reason to hold back. It's about awareness — knowing why certain days feel harder, why your energy or mood shifts, and why some phases may require more recovery support than others.
Menstrual cycle tracking gives female athletes the opportunity to increase symptom self-awareness — understanding the positive features and avoiding the challenging symptoms of the different phases in ways that impact training, recovery, and competition. Athletes should monitor for at least three months to allow meaningful conclusions about their cycles. Read the Research →
PRACTICAL STARTING POINTS:
Track your cycle alongside your training and recovery notes — even a simple app works
Pay attention to energy, mood, sleep quality, and joint comfort across the month
Note which phases feel stronger and which feel harder — patterns will emerge
Share this information with your athletic trainer or physical therapist if you have one
A NOTE ON HORMONAL CONTRACEPTIVES
This is an emerging area and the research is not conclusive. If you're curious about how your contraceptive choice might interact with your training or injury risk, it's worth a direct conversation with your physician.
Recommended Resource
Read:Supporting the Developing Female Athlete — UK Sports Institute →
A comprehensive, evidence-based guide produced by the UK Sports Institute and GB Olympic and Paralympic programmes. Covers the menstrual cycle, injury risk, RED-S, nutrition, hormonal contraception, and more — written specifically for female athletes, coaches, and parents. One of the most complete and accessible resources available on female athlete health.
My take: This resource genuinely changed how I thought about my cycle — not as something to manage around, but as meaningful data about my body. It's one of the most accessible, comprehensive guides I've come across on female athlete health, and it was one of the first things that helped me connect the dots between my hormones, my performance, and my recovery. Highly recommend reading through it regardless of where you are in your athletic journey.
A Note on This Page
Understanding your cycle is one of the most empowering things you can do as a female athlete. The goal of this page is awareness — not anxiety. Every athlete's experience is different, and these patterns won't apply uniformly. Use this information as a starting point for understanding your own body, not as a rulebook.