The impact of excessive exercise on fertility- how much is too much?

We all know that regular exercise is basically the golden ticket to better health, right? You get fitter, stronger, and even sleep better. But when it comes to baby-making, things get a little tricky. Can exercise affect fertility? And does exercise actually help fertility? Turns out, the answer depends on a few key factors like intensity, frequency, and, well… knowing when to take a rest day. In this article, we’re diving into the science behind how exercise affects fertility, how to avoid overdoing it, and where the sweet spot really lies.

How does exercise affect fertility?

Exercise is beneficial for your mood, body composition, and stress levels, which are all important factors to support fertility. Moderate exercise has been shown to improve ovulation, hormone balance, and even the likelihood of conception in both women and men. Some studies even suggest that regular physical activity could improve rates of ovulation frequency in those with polycystic ovarian syndrome (PCOS), which can impact fertility.

But here’s the twist: when exercise intensity ramps up too high, it can actually mess with your reproductive hormones. High levels of exercise, especially without adequate nutrition, can increase cortisol (the stress hormone) and may decrease other hormone levels in women and testosterone in men. This hormonal imbalance can disrupt ovulation and menstrual regularity, making it harder to conceive. In short, exercise can help or hurt depending on the dose.

How much exercise is too much?

So, how do you know when you’ve hit the “too much” mark? Studies suggest that consistently high-intensity exercise, like training for marathons or spending hours daily in the gym, may impact fertility, especially for those who already have low body fat. In women, extreme exercise can lead to hypothalamic amenorrhea, where your period disappears due to stress and low energy availability. For men, excessive exercise can reduce sperm quality and testosterone production.

Signs that you might be overdoing it? Chronic fatigue, mood swings, trouble sleeping, and irregular periods in women can all be red flags that it’s time to ease up and talk to a healthcare professional. Aim for balance: if you’re working out intensely, make sure you’re refuelling well and keeping tabs on your body’s signals.

How to exercise in moderation

The goal is to find that “Goldilocks” level of exercise: not too little, not too much. Here’s a rule of thumb: stick with approx 2.5 hours of moderate activity spread across the week, with a mix of cardio and strength work. Think of this as brisk walking, light jogs, cycling, yoga, or strength training that doesn’t leave you completely wiped out.

If you love high-intensity interval training (HIIT) or lifting heavy, it’s still possible to keep it in your routine, just don’t forget recovery time and a balanced diet to support those intense workouts. Moderation means prioritising rest days and listening to your body. Feeling drained? Maybe that’s a good cue to opt for a gentle stretch or a walk instead of a hardcore workout.

The bottom line 

In a nutshell, exercise can be your fertility friend or foe, depending on how you approach it. While moderate activity can support hormone balance, mood, and overall health (all great for baby plans), excessive exercise can disrupt hormone levels. The trick is finding a sustainable level of activity that supports, rather than sabotages, your fertility goals. Remember, balance is key: keep your body fueled, prioritise rest, and tune into how your body feels along the way.

Related articles:

• Moving with confidence: Exercise tips for preconception and pregnancy
• Foods for fertility: How your diet can support ovulation
• Epigenetics explained: How lifestyle choices impact your future family

Reviewed by Healthylife health experts December 2024.