A few years ago, I was exhausted. Training felt harder than it should. My motivation had disappeared. My body ached in a way that didn't make sense. And then my period stopped.
I assumed I was overtraining. But what I was actually experiencing was something different — something I think a lot of women go through without ever realising what's happening.
It was RED-S. And it wasn't caused by training too much. It was caused by not fuelling enough for the training I was doing, compounded by the pressure, perfectionism, and overwhelm I was carrying in the rest of my life.
What Overtraining Actually Is
Overtraining Syndrome (OTS) is a real clinical condition — defined as prolonged excessive training without sufficient recovery, leading to a performance decline that persists despite more than two weeks of complete rest. We're not talking about feeling tired after a hard week. We're talking about months of deteriorating performance that doesn't recover even when you stop.
True OTS is primarily a condition of elite athletes — people training four to six hours a day, six days a week, for months. For a leisure athlete training a few times a week, it is extremely rare. The research is limited, there are no definitive biomarkers, and diagnosis can only be made retrospectively.
There's also a spectrum worth knowing. Overreaching — feeling beaten up, performance dropping — typically resolves with a few days to two weeks of rest. OTS is the far end: performance that takes months or years to recover. If a few rest days fix it, it wasn't overtraining.
Everything in this post is aimed at leisure athletes. Professional and elite athletes operate under entirely different conditions and should work with a sports medicine specialist.
What Most of Us Are Actually Experiencing
For most of us, what looks like overtraining is usually one of three things:
Not being adapted to the intensity yet. As a beginner, returning after a break, or ramping up load — your body hasn't caught up. This is normal adaptation, not overtraining. Progress more gradually and give the process time.
RED-S — Relative Energy Deficiency in Sport. RED-S occurs when the energy you expend in training isn't matched by what you eat. It doesn't require an eating disorder — it can happen simply through undereating or not understanding how much fuel training actually demands.
The consequences are serious: fatigue, poor recovery, hormonal disruption, mood changes, increased injury risk. And in women, a missing period is one of the clearest warning signals your body can send. Amenorrhea is not a side effect of being fit. It is your body telling you something is wrong. If your period has stopped or become irregular alongside increased training, please take it seriously and speak to a doctor. This is not optional.
RED-S was originally known as the Female Athlete Triad — low energy availability, menstrual disruption, and low bone density. We now know it affects men too, but the menstrual signal in women remains one of the most important and most ignored red flags in recreational sport.
Psychological and life stress. Modern life is demanding — and all of it lands in the body. When you're already carrying a heavy mental load, your perceived physical exhaustion can be completely out of proportion to what you've actually done in training. Psychological stress and physical stress draw from the same pool of resources. Your body doesn't distinguish between a difficult meeting and a hard interval session. Both cost something.
I've experienced this myself — overwhelm and perfectionism manifesting as body pain, no energy, no motivation. On paper I hadn't overloaded my training. But my nervous system was already at capacity before I'd even put on my trainers.
The Reframe
The language of overtraining leads people to one conclusion: do less. But more often, the problem isn't the training — it's the lack of balance around it. Not enough food. Not enough sleep. Not enough recovery. Too much internal pressure.
And here's what I think matters most: done right, training can actually help with the demands of modern life. It improves stress resilience, sleep quality, mood, and cognitive function. It's not another thing depleting you — it builds your capacity to handle everything else. The key is that it's done right — sustainably, with adequate fuel and recovery.
Warning Signs Worth Taking Seriously
- Prolonged fatigue that doesn't improve with rest — tiredness lasting weeks despite sleeping well and reducing training
- Performance declining over weeks despite consistent effort
- Loss of menstrual cycle or significant irregularity — a red flag, not a badge of honour
- Persistent mood changes, irritability, loss of motivation
- Frequent illness or injury
If several of these apply, rest, eat well, and speak to a healthcare provider. These symptoms overlap with medical conditions — thyroid issues, anaemia, depression and others — that need to be ruled out.
Know the difference. Take the signals seriously. And if you want to understand how to train and recover in a way that actually works — start with the posts on building your routine and the role of consistency.