TDEE for Cyclists: Indoor vs Outdoor Burn

A 70 kg cyclist burns anywhere from 280 to 700 calories per hour depending on speed — a 2.5x difference that makes cycling one of the hardest activities to estimate accurately. The gap between a casual commute and a hard group ride is enormous, and most calorie trackers get it wrong because they ignore the two biggest variables: wind resistance and terrain.

How Cycling Affects Your TDEE

Cycling’s calorie cost is dominated by aerodynamic drag at speeds above 20 km/h. At 15 km/h, roughly 50% of your energy goes to overcoming air resistance. At 30 km/h, that number jumps to 80-90%. This is why outdoor cycling at moderate-to-high speeds burns significantly more than indoor cycling on a stationary bike — there is no wind resistance indoors.

The Metabolic Equivalent of Task (MET) values for cycling span a wider range than almost any other common exercise. A leisurely ride at 16 km/h registers at 4.0 MET, while racing at 26-30 km/h hits 10.0 MET. That range reflects cycling’s unique scalability — you can make it a recovery activity or an all-out effort simply by shifting gears.

Calorie Burn by Speed

MET values from the 2024 Adult Compendium of Physical Activities (Ainsworth et al., 2024):

Intensity	Speed	MET	60 kg	70 kg	80 kg	90 kg
Leisure	16 km/h (10 mph)	4.0	240	280	320	360
Light commute	19 km/h (12 mph)	6.8	408	476	544	612
Moderate	22 km/h (14 mph)	8.0	480	560	640	720
Brisk	26 km/h (16 mph)	10.0	600	700	800	900
Racing	29 km/h (18 mph)	12.0	720	840	960	1080
Stationary (moderate)	—	5.5	330	385	440	495
Stationary (vigorous)	—	8.5	510	595	680	765

Calories per hour. Formula: MET x body weight (kg) x 1.0 kcal/kg/hr.

The stationary bike row is the one most people miss. At “moderate” effort on an indoor bike, you burn roughly 30% fewer calories per hour than outdoor cycling at the same perceived effort. The missing wind resistance, lack of terrain variation, and absence of balance demands all reduce the metabolic cost.

Indoor vs Outdoor: The Real Difference

Indoor cycling (stationary bikes, smart trainers) consistently produces lower calorie burn than outdoor cycling at matched power outputs. Three factors explain this:

1. No aerodynamic drag. You are not pushing air, so the same wattage output costs less total energy.
2. No bike handling. Cornering, braking, and balance adjustments recruit stabilizer muscles that a stationary bike does not demand.
3. No terrain variation. Even on “flat” outdoor roads, micro-gradients force constant effort adjustments that spike heart rate.

If you primarily ride indoors, reduce your estimated calorie burn by 15-25% compared to outdoor MET tables. Smart trainers with power meters give the most accurate data — use kJ output (which closely approximates kcal) rather than the trainer’s calorie estimate.

Commuting vs Training vs Racing

Not all cycling is equal for TDEE purposes:

• Commuting (stop-start, traffic lights, moderate pace): MET 4.0-6.0. A 30-minute commute twice daily adds roughly 250-400 kcal for a 70 kg rider. Consistent and sustainable, but lower intensity than training.
• Training rides (sustained effort, structured intervals): MET 8.0-10.0. A 90-minute structured ride burns 800-1,000+ kcal. This is where most of your exercise-related TDEE comes from.
• Racing/hard group rides (threshold and above): MET 10.0-12.0+. Unsustainable for daily training but dramatically increases TDEE during race season.

Which Activity Level Should You Select?

Map your weekly riding to the TDEE calculator:

• Commute only (30-60 min/day, 5 days): Select Lightly Active. Total weekly exercise expenditure is moderate but consistent.
• Commute + 2-3 training rides: Select Moderately Active. This is the typical recreational cyclist.
• 5-6 rides per week (8-12 hours): Select Very Active. Competitive club riders and century trainees.
• 10+ hours per week with structured training: Select Extra Active. Race-focused cyclists and competitive amateurs.

Use our TDEE calculator and select the activity level matching your average training week — not your peak training block.

Nutrition Tips for Cyclists

Fueling rides over 90 minutes is where most cyclists get their nutrition wrong. Your glycogen stores last roughly 60-90 minutes of moderate-to-hard riding. After that, you need to eat on the bike.

• Rides under 60 min: Water only. Your glycogen stores handle this comfortably.
• Rides 60-90 min: 30 g carbohydrates per hour (one gel or banana).
• Rides 90+ min: 60-90 g carbohydrates per hour. This requires practice — your gut needs training to absorb this much during exercise.
• Post-ride: 1.0-1.2 g/kg carbohydrates within 30 minutes for glycogen replenishment, plus 20-25 g protein.

Electrolytes matter more in cycling than most sports because of sustained sweat rates. A hard ride in warm conditions can produce 1-1.5 liters of sweat per hour. Sodium losses of 500-1,500 mg per hour are common. If you cramp on long rides, insufficient sodium is the most likely cause — not potassium or magnesium.

Protein needs for cyclists are moderate: 1.2-1.6 g/kg daily. Endurance cyclists benefit more from adequate carbohydrate intake than from extra protein.

Common Mistakes

1. Using Outdoor MET Values for Indoor Rides

If you ride a stationary bike but use outdoor cycling calorie estimates, you are overestimating your burn by 15-25%. Indoor and outdoor cycling are metabolically different activities.

2. Ignoring the Commute

Cyclists who commute daily often select “Sedentary” because they do not consider their commute as exercise. A 30-minute bike commute each way at moderate pace adds 400-600 kcal to your daily expenditure — that is significant.

3. Not Adjusting for Drafting

Group riding with drafting reduces your energy expenditure by 20-40% compared to solo riding at the same speed. If most of your riding is in a group, your calorie burn is lower than the MET tables suggest.

References

1. Ainsworth BE, Haskell WL, Herrmann SD, et al. 2024 Adult Compendium of Physical Activities: An updated review of MET values. J Sport Health Sci. 2024.
2. Compendium of Physical Activities. pacompendium.com.
3. Faria EW, Parker DL, Faria IE. The science of cycling: physiology and training — part 1. Sports Med. 2005;35(4):285-312.