What hot-weather racing teaches every endurance athlete: how to match sodium to sweat, how much carbohydrate per hour to aim for and when caffeine belongs in your plan.

Two threshold sessions in one day only work if you fuel both. Carbohydrate targets per hour, what to eat in the gap and a practical timeline for runners, cyclists and triathletes.

Heat makes every watt cost more. Here is what happens to your body when racing in the heat, plus practical protocols for acclimation, hydration, sodium and fuelling.

The off-season should be just that. A break.

When the season returns, so does the hard work. Intervals. Long sessions. Races. It all sounds exciting, until you are overtrained, burnt out and carrying an injury.

Most athletes look closely at each session: pace, power, splits, heart rate. Very few look at the total load they are building week after week. That is where problems start.