Too Much of a Good Thing? The Hidden Dangers of Over-Exercising by Kathryn Melvin Women's Health APA Physiotherapist
Exercise is an incredible tool for health, but when you push too hard without proper recovery and nutrition, it can backfire. Over-exercising can lead to hormone imbalances, increased injury risk, and long-term health consequences like missing periods, slow metabolism, and burnout.
One of the most serious consequences of over-exercising is Relative Energy Deficiency in Sport (REDs)—a condition where the body doesn’t get enough fuel to keep up with high activity levels. This can disrupt hormones, bone health, metabolism, and overall well-being.
Let’s dive into the signs of overtraining, how it affects your hormones, and simple, practical tips to help you stay strong and balanced.
1. Are You Overtraining? Warning Signs to Watch For
Over-exercising doesn’t just mean training for hours a day—it can also mean not fueling properly for your workouts or not allowing enough recovery time. Here are some red flags:
Physical Symptoms
Constant fatigue despite getting enough sleep
Lingering muscle soreness that never fully goes away
Frequent injuries such as stress fractures, shin splints, and tendonitis
Weakened immune system, leading to more frequent illnesses
Hormonal & Metabolic Symptoms
Irregular or missing periods
Difficulty building muscle despite consistent training
Unexplained weight fluctuations
Cravings and blood sugar crashes
Mental & Emotional Symptoms
Irritability or mood swings
Loss of motivation for workouts
Poor sleep quality, trouble falling asleep, or waking up feeling unrested
2. Why Over-Exercising Messes With Your Hormones
Hormones control everything from energy and metabolism to mood and reproductive health. Overtraining, especially when combined with low energy intake, can throw them out of balance.
The Hormones Most Affected by Over-Exercising:
Cortisol (Stress Hormone) – Chronically high from too much intense exercise, leading to poor sleep, anxiety, and belly fat storage.
Estrogen & Progesterone (Women’s Hormones) – Low estrogen from over-exercising can cause irregular or missing periods, weak bones, and mood swings.
Testosterone (Muscle & Libido Hormone) – Low levels lead to muscle loss, low libido, and fatigue (affecting both men and women).
Thyroid Hormones (T3 & T4, Which Control Metabolism) – Low levels slow metabolism, causing fatigue, weight changes, and sluggish digestion.
Insulin (Blood Sugar Regulation) – Over-exercising can disrupt insulin levels, leading to energy crashes and cravings.
3. Why Losing Your Period is Cause for Concern
If you’re a woman and your period disappears due to intense exercise, it’s a sign of hormone dysfunction.
What Causes It?
Over-exercising without proper recovery
Not eating enough (especially carbs and fats)
Too much stress (physical and mental)
Why Is It Dangerous?
Weakened bones & higher risk of osteoporosis – Low estrogen reduces bone density, increasing fracture risk.
Metabolic slowdown & fatigue – Hormone imbalances make it harder to sustain energy and recover.
Heart health risks – Estrogen protects the heart, and low levels can increase cardiovascular issues.
Fertility problems – If your cycle is missing, your body isn’t ovulating, which can affect future fertility.
If your period is missing for three months or more, it’s time to adjust your nutrition, exercise routine, and stress levels.
4. Simple Tips to Prevent Over-Exercising & Keep Your Hormones Happy
The good news? You don’t have to stop exercising—just train smarter, not harder. Here are easy ways to support your body while staying active.
A. Fuel Your Body Properly
Eat before drinking coffee – Caffeine on an empty stomach spikes cortisol. Try a small meal first.
Have a snack before high-intensity workouts – A banana with peanut butter or a small smoothie helps prevent energy crashes.
Carbs are your friend – Whole grains, fruits, and potatoes fuel workouts and prevent hormone imbalances.
Healthy fats support hormones – Avocados, nuts, and olive oil help with estrogen and testosterone production.
B. Train Smart, Not Excessively
Balance intensity – Mix strength training, cardio, and rest days for a well-rounded routine.
Include recovery activities – Yoga, walking, or mobility work reduce stress on your body.
Prioritize strength over excessive cardio – Too much running or HIIT can elevate cortisol. Strength training supports metabolism and bone health.
C. Prioritize Recovery & Rest
Aim for 7–9 hours of sleep – Your body repairs itself while you rest.
Take at least 1–2 full rest days per week – More isn’t always better. Recovery is where muscle growth happens.
Listen to your body – If you’re feeling exhausted or moody, swap an intense session for something lighter.
D. Watch for Signs of Under-Fueling
Always feeling cold
Low energy or dizziness
Hair thinning or brittle nails
Missing or irregular periods
If you notice these symptoms, try increasing your calorie intake and reducing exercise intensity for a while. Your body needs fuel to function properly.
Final Thoughts: Exercise for Health, Not Burnout
Exercise should boost your energy, not drain it. If you’re experiencing constant fatigue, missing periods, or frequent injuries, it’s a sign to adjust your routine. Train smarter, fuel properly, and allow recovery time. Long-term health is about balance, not extremes.
References:
PhysioWorks 2024, RED-S: A Guide for Athletes on Energy Balance, PhysioWorks <https://physioworks.com.au/sports/sports-health/red-s/>
Brighten, J 2024, Understanding RED-S: The Hidden Health Risk for Athletes and Active Individuals, Dr. Jolene Brighten, viewed 19 May 2025, <https://drbrighten.com/red-s/>
Australian Institute of Fitness 2024, Overtraining - The Warning Signs, Australian Institute of Fitness, viewed 19 May 2025, <https://fitness.edu.au/the-fitness-zone/overtraining-the-warning-signs/>
Abundant Exercise & Physiotherapy 2024, Overtraining Syndrome in the Athlete, Abundant Exercise & Physiotherapy, <https://www.rh-exphys.com.au/resources/overtraining-syndrome-in-the-athlete>