CoachingAnswer

HOW DO I GET LIGHTER FOR CLIMBING WITHOUT LOSING POWER?

By Anthony WalshRoadman CyclingUpdated 10 July 2026

ANSWER

Lose 0.5-0.7% of body weight per week through a moderate daily deficit of 300-500 calories, timed to avoid under-fuelling on hard training days. This rate preserves muscle mass and power output while reducing body fat — the only tissue you want to lose. Faster weight loss consistently degrades FTP, sprint power, and recovery quality. Most amateur cyclists overestimate how lean they need to be: even a 2-3 kg reduction in body fat improves climbing watts-per-kilo meaningfully without the hormonal and performance consequences of getting excessively lean.

KEY TAKEAWAYS

A weekly weight loss of 0.5-0.7% of body weight protects power output and muscle mass during a cutting phase.
Create a calorie deficit on easy days and rest days, not on hard training days — under-fuelled interval sessions cap adaptation.
Even a modest 2-3 kg of fat loss improves climbing W/kg by 0.1-0.2 — enough to feel the difference on any serious gradient.
Body fat below 8-10% for men or 15-18% for women carries hormonal risks including reduced testosterone, poor sleep, and increased injury rates.

WHO THIS IS FOR

IS THIS YOU?

Riders preparing for a hilly sportive or mountain event

You have an event with serious climbing and want to arrive at race weight without compromising your fitness on the start line.

Cyclists carrying extra body fat who want better climbing performance

You know you are carrying weight that is slowing you on climbs, but previous attempts at losing it have left you feeling flat and under-powered.

THE ROADMAN VIEW

Weight loss for climbing is the most commonly mismanaged aspect of amateur cycling. Anthony sees it constantly — riders crash-dieting before an event, under-fuelling their key sessions, wondering why their power numbers have dropped despite training more. The paradox is that they are working harder but getting weaker because the body cannot adapt to training stress when it is running on fumes.

The approach that works is boringly moderate. A 300-500 calorie deficit on easy days and rest days, while fuelling hard sessions properly, produces a sustainable 0.5 kg per week of fat loss. Over eight weeks that is 4 kg — a meaningful difference on a climb — without the immune suppression, mood collapse, and power decline that comes with aggressive dieting. The masters cyclists Anthony coaches are particularly susceptible to overdoing it because recovery is already slower after 40 — add calorie restriction on top and everything falls apart.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Prof Asker JeukendrupExercise physiologist, Loughborough University
Energy periodisation — fuelling for the work required — is the most effective strategy for achieving body composition changes without performance decrements. Athletes should eat to support their training sessions fully, particularly high-intensity and long-duration sessions, and create their calorie deficit on recovery and rest days when the metabolic consequences are minimal. This approach consistently outperforms uniform calorie restriction across all days.

PRACTICAL APPLICATION

DO THIS WEEK

Calculate your baseline calorie needs and create a periodised deficit
Estimate your total daily energy expenditure (TDEE) using a calculator or by tracking intake and weight for 2 weeks. On hard training days, eat at or slightly above TDEE to fuel sessions and recovery. On easy and rest days, eat 300-500 calories below TDEE. This creates a weekly deficit of roughly 1,500-2,500 calories — enough for 0.2-0.3 kg of fat loss per week.
Protect protein intake throughout the cut
Maintain 1.6-2.0 g of protein per kg of body weight daily to preserve muscle mass. Distribute this across 4-5 meals with at least 30 g per sitting for maximum muscle protein synthesis. Protein is the most satiating macronutrient, so prioritising it also helps manage hunger during the deficit phase.
Monitor power output weekly to detect performance loss
Track your 5-second, 1-minute, and 20-minute power numbers weekly. If any drop by more than 3-5% from baseline, the deficit is too aggressive — reduce it by 200 calories per day or add a full-fuel day midweek. Power loss is the canary in the coal mine for excessive restriction.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEUnder-fuelling on interval or hard training days.
FIXHard sessions demand full fuelling — both before and during the ride. Restricting calories around intervals reduces the quality of the session and blunts the adaptation. Create your deficit on easy and rest days instead.
MISTAKETargeting a race weight that is unrealistically lean.
FIXProfessional cyclists are lean because their job is to ride 25-30 hours a week. An amateur riding 8-12 hours per week cannot sustain the same body fat percentage without health consequences. Aim for the lightest weight at which you feel energised, sleep well, and maintain power output — that is your optimal race weight.
MISTAKELosing weight too quickly and mistaking muscle loss for fat loss.
FIXIf the scale drops more than 1% of body weight per week, you are likely losing muscle tissue as well as fat. Slow the rate by increasing calories on hard training days. A DEXA or bioimpedance scan every 4-6 weeks can track body composition changes separately from total weight.

FAQ

FREQUENTLY ASKED QUESTIONS

How much does weight affect climbing speed?

On a 7% gradient at 250 watts, losing 2 kg reduces your climbing time by approximately 45-60 seconds per 10 minutes of climbing. The steeper the gradient, the greater the impact — on a 10% climb, the same 2 kg loss saves 60-80 seconds. Use a power-to-speed calculator to model your specific scenario.

Should I lose weight during the racing season?

Ideally not. Weight loss is best done during the base or early build phase when training intensity is lower and the body can tolerate a mild deficit without compromising key sessions. Attempting to lose weight during high-volume, high-intensity racing phases risks under-recovery and illness.

Is it better to lose weight or gain power for climbing?

Both improve W/kg, but gaining power is generally the healthier and more sustainable approach for most amateur cyclists. If you are already at a reasonable body fat percentage (12-18% for men, 20-28% for women), focusing on power development through training is usually more productive than further weight loss.