When excitement feels like danger
When you experience the race day excitement, it changes what goes on inside of your body. You release stress hormones such as adrenaline and that has several effects.
- Raises your heart rate and breathing
- Pushes sugar into your bloodstream
- Encourages your muscles to burn through stored carbohydrate (glycogen) right away
This means that even if you don’t feel nervous, your body can start acting like it’s already deep into a hard effort, long before you actually need that energy.
Why stress burns carbs faster
Normally, your body uses a mix of fat and carbs to fuel endurance exercise. A higher proportion of fat is used when riding at steady medium intensity. On the other hand, a higher proportion of carbs is used when pushing at high intensity. But stress hormones shift that balance toward burning mostly carbs, regardless of the intensity. That’s useful if you need a short burst of power, but it also drains your limited glycogen stores faster than usual. This can set you up for an energy crash, a “bonk” later in the race.
Watch out for these signs that stress may be burning your fuel
- Heart rate 10-15 beats higher than normal during a warm-up
- Feeling jittery or flushed
- Sweating before the effort begins
- Breathing harder than expected at easy pace
- Wanting to eat carbs earlier than usual
How to avoid an early bonk?
Practice under pressure: Include training sessions that mimic race nerves, like group rides, local training races, or hard starts. Notice how your body reacts and practise staying calm while sticking to your fuelling plan. The more you do it, the less likely your body is to overreact to it.
Fuel early and often: Don’t wait until you feel hungry or tired. Begin taking in carbs within the first 30-45 minutes of a longer event. Even in shorter races, you may need more carbs than you expect, because adrenaline is burning through them faster. Spread intake steadily rather than taking huge amounts at once.
Start easier than you feel you should: Adrenaline can trick you into feeling superhuman in the first hour. Resist the urge to put the hammer down early, or you’ll empty the tank too fast. Start conservatively and build.
Manage nerves before the start: Arrive early, do a warm-up you’ve practised, and try calming techniques like deep breathing.
Should you take a gel before the start?
Yes, if the race begins with an all-out effort like cyclocross, short-track MTB, or a criterium.
No, if there’s a neutral roll-out or delay before the real effort begins. In that case, steady fuelling once you’re moving is usually better.
Race-day stress isn’t just mental it changes how your body burns fuel. Adrenaline can make you burn through carbs 30–50% faster in the first hour than you do in training. Thankfully, you can do something about it. Fuel earlier, pace smarter, stay calm, and you’ll reduce the negative effects of race day nerves.
