Body composition is what the brand bible calls "the hidden universal motivator." Almost every cyclist cares about it deeply but rarely talks about it openly. There's a reason for that — the conversation around weight in cycling has historically been toxic, tied to eating disorders, unhealthy restriction, and a culture of suffering.
We're going to talk about it differently. Because body composition — the ratio of lean mass to fat mass — is genuinely one of the biggest levers for climbing performance. But the approach matters as much as the outcome.
Why Composition Matters More Than Weight
Two riders both weigh 75kg. Rider A is 12% body fat with 66kg of lean mass. Rider B is 20% body fat with 60kg of lean mass. Same scale weight. Very different cyclists.
Rider A has 6kg more muscle producing power. At the same FTP-to-weight ratio, Rider A produces roughly 20 more watts because there's simply more muscle tissue doing work. On a 20-minute climb, that's the difference between holding the group and watching it disappear.
The scale tells you one number. A body composition measurement tells you two: how much of you is engine, and how much is cargo.
Target Ranges for Cyclists
| Level | Men (Body Fat %) | Women (Body Fat %) | |---|---|---| | Recreational | 15-25% | 20-30% | | Competitive amateur | 10-15% | 16-22% | | Elite amateur | 8-12% | 14-18% | | Professional | 6-10% | 12-16% |
These are ranges, not targets. The right body fat percentage for you depends on your genetics, your training load, your health markers, and how you perform at different compositions. Going below 8% (men) or 14% (women) carries real health risks and should only be done under professional supervision.
How to Measure
Smart scales (Withings, Garmin) use bioelectrical impedance. They're not accurate in absolute terms but they're consistent — which means they're useful for tracking trends over time. Weigh yourself weekly under the same conditions (morning, fasted, after bathroom).
DEXA scan gives the most accurate single measurement. Worth doing once to calibrate, then use smart scales for ongoing tracking.
Skinfold callipers are accurate in trained hands but variable between testers. If you use them, use the same person every time.
The Approach That Works
The fuel for the work required framework is how I lost 7kg while eating more food. The principle: high carbohydrate intake around hard training sessions, reduced carbohydrate on easy days and rest days. The weekly calorie deficit accumulates naturally without ever restricting food when your body needs it.
The key insight: you never under-fuel a hard session. The deficit comes from easy days, not training days. This preserves power, maintains recovery, and avoids the binge-restrict cycle that most dieting creates.
Use our Race Weight Calculator to find your target range, and our Energy Availability Calculator to make sure you're not under-fuelling.
Key Takeaways
- Body composition (lean mass vs fat mass) matters more than scale weight
- Two riders at the same weight can have very different power output based on composition
- Target ranges for competitive amateurs: 10-15% men, 16-22% women
- Track trends with weekly weigh-ins under consistent conditions
- Use the fuel for the work required framework — deficit on easy days, not hard days
- Never go below healthy ranges without professional supervision
- Use our Race Weight and Energy Availability calculators together
- Use the Fuelling Calculator to set your carb targets for hard training days
- Avoid fasted riding — it undermines body composition goals
- For the common mistakes, read 5 reasons you can't lose weight
- Power-to-weight ratio explains why W/kg matters more than the number on the scale
