Unlike in running, performance in cycling is less dependent on body weight - with the exception of hill climbing events, and also stage racing on hilly terrain. Performance in cycling is more often dictated by the ability to maintain the highest absolute power output.

We cover this topic in a factsheet, but here is a summary of the main issues.

Example - Take a cyclist who weighs 68kg

• in a challenge of riding up a 15% hill that is 800m long, at their present weight, time would be approx 340s.
• if they lost 3kg, they would improve their time by 14s
• on the flat though, and holding 250W for a 10 mile time trial, this would give times of 23:17 and 23:08 - only 9s saving over this length event
• however, losing 3kg may actually decrease the sustainable power - as muscle mass contributing to power production may decrease. Data collected on a cyclist who gained 3kg shows the sustainable power increasing by 13W; or in our example, that would give a 10 mile time of 22:42!

Conclusion? Gaining power gives you back twice more in performance than losing weight! So make that your focus if you are prioritising time trialling, or criterium type races on less arduous terrain.