Signs you're overtraining — and what to do about it
"Overtraining" gets thrown at any week you feel tired, but most of that tiredness isn't overtraining at all. It's overreaching — the normal, useful fatigue that comes from a hard block. The distinction matters, because one fixes itself in days and the other can sideline you for months.
Functional overreaching is what training is supposed to feel like. You pile on load, you feel flat, and after a few easy days you bounce back fitter than before. That's the whole point of a hard week followed by recovery.
The trouble starts when the fatigue stops clearing. Non-functional overreaching is overreaching you didn't recover from — it takes two to three weeks to shake, and your performance stalls instead of rising. Push through that, and you risk overtraining syndrome, a deep state that can take months to over a year to fully resolve.
The early warning signs are worth knowing, because they show up before you crater:
- Resting heart rate that stays elevated — TrainingPeaks flags a sustained rise of about 5 bpm over your average — even on rest days
- HRV that trends low for longer than usual despite taking recovery
- Legs that feel flat and heavy on runs that used to feel easy
- A training plateau: you keep working hard but stop improving
- Poor sleep, low mood or motivation, and getting sick more often
No single one of these is proof. It's the cluster, and the trend over a week or two, that tells the story. A rough night's sleep plus one high RHR reading is just life.
The fix is almost always less satisfying than people want: back off early. Cut volume, drop a hard session, take extra easy or rest days for a week. A deload taken at the first signs costs you a few days. A forced layoff after you've dug the hole costs you weeks or months. Recovery is the cheap insurance here.
What to do with this: treat a multi-day cluster of rising RHR, falling HRV, flat legs, and stalled performance as a stop sign, not a challenge. Pull back for a week before your body pulls you back for a season.
RunNerd watches the trend, not the bad day. When your morning RHR trends up around 5+ bpm and HRV trends down across several days — and your easy pace starts drifting slower at the same heart rate — the coach reads that as accumulating fatigue, not a fitness gain coming. It defers the next quality workout, stretches the easy days, and if the pattern holds it cycles in a deload (roughly half volume, one fewer hard session) before the hole gets deep. When the trend recovers, it picks the plan back up.