Running fasted

An easy run of up to about an hour on an empty stomach is fine for most healthy runners; hard sessions and long runs go better with food.

• Running fasted burns a larger share of fat during the run, but doesn’t lead to more fat loss over time.
• Intervals, tempo runs and runs over 75 to 90 minutes usually suffer without carbohydrate.
• Drink a glass of water before; a coffee is fine; carry a gel in case you feel weak.
• Skip it if you have diabetes or tend to under-eat, and ask your doctor if unsure.

Stop and eat if you feel dizzy or shaky, and have a proper meal with carbohydrate and protein afterwards.