The Free Upgrade

I'd bet there's a power meter on your bike, a heart rate strap kicking around, possibly a stack of curated supplements — all bought chasing more watts. But there’s an upgrade none of that touches: it's free, takes up no space, doesn’t need batteries, and most riders barely use it right.

Training is a stimulus, a stressor, and it signals your body to adapt to that stress. The actual adaptation — the part that turns quality training into fitness — happens almost entirely while you're asleep. During deep sleep, your body releases somewhere between 50 and 70 percent of its daily, natural growth hormone. (That’s the stuff that rebuilds the muscle fiber you just tore down.) Skip the sleep, and you've paid for the workout without collecting the adaptation.

Cut sleep short for even a few nights and the cost compounds: testosterone can drop 10 to 15 percent, cortisol climbs, glycogen stores struggle to refill. It's not just performance, either — a year-long study of endurance athletes, cyclists included, found that sleeping under 7 hours a night raised injury risk by 51 percent, while sleeping more than 7 cut it by 37 percent.

This is your target: 7.5 to 8.5 hours of actual sleep, more during a heavy training block. Not time in bed — time asleep.

No gadget on the market gets you more for free.

Explore more:

Read: General health complaints and sleep associated with new injury within an endurance sporting population (Johnston et al., 2020)

Listen: Sleep, Recovery & Wearables: Evidence-Based Strategies with Prof. Shona Halson (Stronger with Time podcast)

Watch: Sleep Yourself Fitter | Recovery That Makes You A Faster Cyclist (GCN)

See you next week,

Steve