Training Load & Recovery

Stress plus recovery equals fitness

A workout is a stimulus, not the adaptation itself. The fitness gains — more mitochondria, more blood volume, stronger tissues — are built in the hours and days after, when you've recovered. That's why a plan alternates hard and easy, and why piling on more hard work without recovery makes you slower, not faster. The goal isn't to maximize stress; it's to maximize the stress you can absorb and adapt to.

How much is too much

The strongest predictor of overuse injury you can control is how fast you ramp up. Large spikes in load relative to what you've been doing raise injury risk, while load built up gradually is protective — fitness earned slowly is also armor¹. A useful lens is your recent (last week) training versus your longer-term baseline (last month): when the recent jump gets big, risk climbs². Treat these as rough guardrails, not precise rules — individual tolerance varies enormously with training age, history, and life stress. Build gradually, and let down weeks consolidate the gains.

The recovery levers

Recovery isn't passive — it's a set of inputs you control, in rough order of impact:

• Sleep — the single biggest lever. Most of the body's repair and hormonal recovery happens during sleep, and short or poor sleep degrades performance and recovery³. Protect 7–9 hours.
• Fuel — you can't rebuild without raw materials. Adequate carbohydrate and protein, especially around hard sessions, supports adaptation⁴.
• Easy days kept genuinely easy — running easy days too hard is the most common way runners sabotage recovery.
• Rest days — unloaded time lets tissue repair and your nervous system reset. They are part of the plan, not a failure of it.

Reading your body

Numbers from a watch — resting heart rate, HRV, "recovery scores" — are useful inputs, but they're inputs to judgment, not verdicts. Pair them with how you actually feel: persistent soreness, flat legs over several days, disrupted sleep, low mood, or a string of workouts that feel harder than they should are classic signs you're under-recovered. One bad day is noise; a multi-day pattern is signal — back off before it becomes an injury or burnout.

Fitness is durable; age changes the math

Reassuringly, fitness fades slowly — a few days of rest or a proper taper sheds fatigue while keeping the fitness you built, which is exactly why tapering works⁵. Recovery capacity does change with age: endurance capacity declines gradually with age, driven largely by reductions in VO₂max and in the training intensity and volume an athlete can sustain — though a consistent, well-recovered 55-year-old can rival a 30-year-old with the same habits⁶. In practice many masters runners also find they need a bit more recovery between hard efforts, but it's the individual recovery response, not the birthday, that matters.