Cycling Nutrition & Fuelling

Overview

Cycling is the endurance sport where nutrition mistakes are punished most visibly. Bonk on a run and you slow down; bonk on a bike 60km from home and you're in serious trouble. Get fuelling right and you'll recover faster between sessions, finish long rides strong, and enjoy the riding more.

This guide covers the three windows that matter — before, during, and after — plus how fuelling changes with ride intensity and duration. It's pitched at riders doing 3-8 hours a week who want to move past "a bar and some water" improvisation and understand what actually drives endurance fuelling.

Golden Rule: Cycling performance past ~90 minutes is a carbohydrate game. Train your gut to take in 60-90g of carbs per hour during long efforts and you'll transform what you can do on a bike.

The Three Windows

1. Before the Ride

Short ride (<90 min, moderate intensity): A normal meal 2-3 hours before. No special fuelling needed.

Medium ride (90 min-3 hours): Carb-focused meal 2-3 hours before (porridge with banana and honey, or toast with peanut butter and jam). 300-500 kcal.

Long ride (3+ hours) or hard intervals: Two eating windows:

• 3 hours before: 500-800 kcal carb-focused meal
• 20-30 min before: 20-30g quick carbs (banana, gel, sports drink)

What to avoid:

• High-fat, high-protein meals within 2 hours — they slow carbohydrate absorption
• Large fibrous salads before long rides (gut distress territory)
• Alcohol the night before (dehydration, poor sleep = compromised day)

2. During the Ride

This is where most cyclists under-fuel. The science is clear: trained athletes can absorb 60-90g carbs per hour during exercise. Most people eat 20-30g/hour and wonder why they fall apart at hour 3.

Ride duration	Carbs per hour	What it looks like
<60 min	0 (optional)	Water only
60-90 min	30g	One gel, or one bar, plus water
90 min-3h	45-60g	Gel + sports drink + small bar
3h+	60-90g	Sports drink in bottle + solid food every 30 min

Carbohydrate sources (per rider's tolerance):

Source	Carbs (approx)	Notes
Energy gel	20-25g	Fast-absorbing, easy but gets dull
Sports drink (500ml, 6%)	30g	Combines carbs + hydration
Banana	25g	Great, slightly awkward to carry
Flapjack (thick slice)	35-45g	UK café favourite — dense, satisfying
Malt loaf (thick slice)	30g	Underrated ride food
Rice cake	20-25g	Easy to pack, simple to eat
Soreen bar	30g	Pocket-sized classic

Combining sources matters. The gut absorbs different sugars through different transporters. Mixing glucose + fructose (most quality sports drinks and gels do this) lets you absorb more carbs per hour without distress.

3. After the Ride

The 60-minute window matters less than the next 24 hours. Old wisdom said "refuel within 30 minutes." Newer evidence: as long as total intake over the next 24 hours is adequate, timing is far less critical than volume.

However, if you're doing another session within 24 hours, fast refuel helps:

• Within 60 min of a hard ride: 1-1.5g carbs per kg bodyweight + 20-30g protein
• Example for a 70kg rider: 80-100g carbs + 25g protein
• Practical: a large bowl of cereal with milk + toast + a protein shake

Hydration rule of thumb: weigh yourself before and after a long ride. Every 1 kg lost = 1.5L fluid. Drink back 150% of what you lost over the next 2-3 hours.

Hydration Strategy

Water alone is not enough for rides over 60-90 minutes. Sodium loss is real:

• Average cyclist: 500-800 mg sodium per litre of sweat
• Heavy sweaters: up to 1500 mg/L
• Light sweaters: 300-500 mg/L

Electrolyte options:

• Sports drinks (like SiS, Science in Sport, High5, Precision Fuel) — dose on the bottle
• Salt tablets / electrolyte tabs dissolved in water
• Homemade: 1L water + 40g sugar + 1g salt + lemon juice = an acceptable sports drink

Signs of under-fuelling / dehydration on the bike:

• HR creeping up at same power
• Pace dropping in final third of ride
• Cramping (usually sodium, not "just dehydration")
• Dizziness at stops
• Poor decision-making ("I'll just take the shortcut through this sketchy road")

Training the Gut

Your gut absorbs what you've trained it to absorb. If you normally take 30g carbs/hour, trying to take 90g/hour on race day will cause distress.

Gut training protocol:

• Weeks 1-2: Target 40g carbs/hour on long rides
• Weeks 3-4: Target 60g carbs/hour
• Weeks 5-6: Target 80g carbs/hour
• Weeks 7+: Target 90g carbs/hour

This applies specifically to rides over 90 minutes. Short rides don't need this volume.

Match Fuelling to Intensity

Intensity	Fuelling priority
Z1-Z2 (easy)	Water + minimal carbs (20-30g/h). Fat is primary fuel.
Z3 (tempo)	Moderate carbs (40-60g/h). Mixed fuel.
Z4+ (threshold and above)	High carbs (60-90g/h). Glycogen-dominant.
Intervals	Consume carbs between intervals, not during hardest efforts

"Fasted rides" (before breakfast, water only) have a place for building fat oxidation — but only for easy Z2 rides under 90 minutes. Doing fasted intervals is counter-productive: you'll train poorly and adapt less.

Race-Day / Long Event Fuelling

For a 4-6 hour event like a sportive or gran fondo:

Night before:

• Normal-sized carb-rich dinner (rice, pasta, potato — whatever you normally eat)
• No late-night sugary snacks (disrupted sleep)
• Hydrate consistently throughout the day before

Morning of:

• 3 hours before start: 600-900 kcal carb-focused breakfast (porridge, banana, honey, white bread with jam)
• 30 min before start: gel or electrolyte drink

On the bike:

• First hour: 40-60g carbs (ease the gut in)
• Hours 2-5: 80-90g carbs per hour
• Final hour: 60g + caffeine (gel with caffeine, or swapped-in cola)
• Water: 500-750ml per hour depending on temperature

At the finish:

• Immediately: 500ml fluid + carbs
• Within 60 min: proper meal
• That night: eat well, hydrate, sleep early — recovery begins immediately

Special Situations

Hot weather (25°C+):

• Fluid intake up 20-30%
• More sodium (upper end of your range)
• Consider pre-cooling (cold drinks, wet ice bandana)

Cold weather:

• Warm bottles (caffeine tea, warm sports drink)
• Appetite may drop — eat by the clock, not when hungry
• Sweat still happens; don't skip fluid

Long climbs:

• Fuel BEFORE the climb, not during. Gut absorption slows at high intensity.
• Stash extra carbs in pockets for the descent recovery

Common Mistakes

• Under-fuelling long rides. 30g/hour is the default for most recreational cyclists. It's half what you actually need on 4-hour rides.
• Trying new foods on race day. Everything needs to be trained. Unfamiliar gels, new drink mixes, exotic bars — all risks you don't need.
• Overcaffeinating early. Save caffeine for the final 2 hours where it genuinely helps. Using it at hour 1 just masks under-fuelling.
• Treating the café stop as refuelling. Café stops are great, but coffee and cake isn't a plan. Eat before AND at the café, not instead of.

What's Next

Pair this with FTP & Power Training for Climbers — nutrition is the under-training most riders do. Or, if you're a triathlete, the Triathlon Nutrition Strategy integrates swim/bike/run fuelling.