The 1500 m Runner Who Is Getting Slower: Overreaching, Illness or Overtraining?

Verdict: most consistent with non-functional overreaching plus a likely non-training cause (sleep loss and possible infection). Overtraining syndrome is not yet supported.

• Overtraining syndrome is a diagnosis of exclusion. It requires a long-standing performance decrement (usually weeks to months), mood disturbance and endocrine or immune changes, with all other explanations ruled out. Seven weeks of decline with an obvious sleep debt and a sore throat does not meet that bar.
• Strongest evidence: performance fell (4:38 to 4:52–4:55) while the training load rose. A load that was previously tolerated is now producing worse results, which is the defining feature of non-functional overreaching.
• Supporting evidence: resting heart rate up 9 bpm, heavy legs, appetite loss and disturbed sleep all fit accumulated fatigue and raised sympathetic drive.
• Confounded evidence: the sore throat and the 2 kg mass loss could be infection or dehydration rather than training stress; 5.5 hours of sleep during mocks alone can raise resting heart rate by several beats and slow recovery; one resting heart rate reading has poor reliability.
• What would change the verdict: fever or a persisting sore throat means infection must be excluded medically. If performance is still depressed after two to three weeks of reduced load and normal sleep, non-functional overreaching is confirmed and overtraining syndrome becomes more plausible.

1. Screen him medically first. A sore throat with a raised resting heart rate and appetite loss warrants a check before any hard session, because training through a viral illness carries a small but serious cardiac risk.
2. Do not add the third interval session. The problem is recovery, not stimulus; adding load to an athlete already showing a performance decrement deepens the hole.
3. Cut volume by 40–50% (70 km to about 35–40 km) for 10–14 days, but keep one or two short quality sessions (for example 6 × 400 m at 70–72 s with full recovery). Rationale: intensity maintains VO2max and running economy, while volume is the main driver of the accumulated fatigue; cutting volume restores autonomic balance with little detraining.
4. Sleep and nutrition: 8–9 hours a night, enough carbohydrate to restore glycogen, iron-rich foods, and a ferritin check if fatigue persists - distance runners are a high-risk group.
5. Re-progress only when markers normalise: rebuild volume by about 10% per week if morning heart rate, mood and session RPE are back to baseline.
6. Taper the final 10–14 days: volume down 40–50%, intensity maintained, one race-pace session. Tapering works through glycogen restoration, clearance of fatigue and restored autonomic function.

Use several markers together, because no single measure diagnoses fatigue:

• Morning resting heart rate as a five-day average (not one reading), plus sleep hours and how he feels on waking.
• Session RPE at a fixed pace - the key functional marker. If the same easy run feels easier at the same pace, recovery is happening.
• Body mass and appetite, which should stabilise if the cause was fatigue rather than illness.
• A controlled 3 km time trial at the end of week two, not an all-out 1500 m.
• The sore throat: persistent or worsening symptoms move the decision from coaching to medical referral.

Decision rules. If resting heart rate drifts back towards 52–55 bpm, sleep is over 8 hours and RPE at fixed pace falls, the plan is working and load can be rebuilt. If resting heart rate stays above 60 with normal sleep, or the sore throat persists, stop and refer. A single good session is not evidence - trends over two weeks are. Avoid the trap of testing him hard to see whether he is better, which would re-create the overload.