Skip to content
CoachingAnswer

WHY DOES MY POWER FADE ON LONG RIDES?

By Anthony WalshRoadman CyclingUpdated

WHO THIS IS FOR

IS THIS YOU?

The sportive and long-ride rider who always fades late

You're strong for the first 2–3 hours but fall apart in the final quarter of every long ride.

The endurance cyclist building up to 4+ hour rides

You're extending duration and hitting power walls that don't appear on shorter rides.

THE ROADMAN VIEW

The Roadman view

The most common conversation in cycling communities goes something like: 'I was strong for three hours and then completely fell apart.' And the response is almost always the same question back: 'What were you eating?' The answer is usually not enough. Power fade on long rides is, in the vast majority of cases, a fuelling problem wearing a fitness disguise.

The physiology is simple. Your muscles store roughly 90 minutes to 2 hours of glycogen at moderate-hard intensities. Once it runs low, your body can't sustain power from fat oxidation alone — it's too slow. You slow down, the power number drops, and it feels like your legs have given up. They haven't. They've run out of premium fuel.

Sam Impey's position on the podcast was blunt: athletes who start fuelling at hour three because 'they didn't feel hungry before then' have already lost the battle. The gut absorbs carbohydrate on a delay. You need to be taking in fuel continuously from 30–45 minutes in, long before the fade starts, building a running buffer that prevents the deficit.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

  • Dr Sam ImpeyWorld Tour sports nutritionist

    Power fade on endurance rides is rarely a true fitness failure — it's almost always a carbohydrate availability problem. Athletes who fuel proactively from the first 45 minutes almost never hit the wall in the same way as those who wait until they feel empty.

    Hear it: Why Pros' 120g Carb Rule Fails Amateurs | Roadman Cycling
  • Dan LorangHead of Performance, Red Bull–Bora–Hansgrohe

    An underdeveloped aerobic base means the body relies more heavily on glycogen even at moderate intensities. Riders with poor zone 2 development use carbohydrate faster, hit depletion sooner, and fade earlier. Base training is a fuelling efficiency strategy as much as a fitness one.

    Hear it: 13 Years Of Coaching Pros: What Amateurs Don't Know

PRACTICAL APPLICATION

DO THIS WEEK

  1. Set a fuelling alarm on your head unit

    Programme a recurring alert every 20 minutes from minute 40 of your ride. Each alert: eat something. Don't rely on hunger cues. On a 4-hour ride at 60g/hr, that's about 240g of carbohydrate — roughly 4–6 gels or equivalent.

  2. Start the ride well-stocked

    Eat a carbohydrate-rich meal 2–3 hours before the ride. Even with mid-ride fuelling, starting with low glycogen from the morning means you're digging out of a hole from the first pedal stroke.

  3. Build genuine aerobic base in training

    Consistent zone 2 riding builds fat oxidation capacity and mitochondrial density — meaning your muscles become more efficient at using fat at moderate intensities, preserving glycogen for the hard efforts later in the ride.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

  • MISTAKEWaiting until you feel flat before eating.

    FIXFuel on a clock from 30–45 minutes in. By the time the fade hits, you're already hours behind on carbohydrate replenishment.

  • MISTAKEFasting before long easy rides to 'burn fat'.

    FIXFasted long rides can work for very easy zone 2 efforts, but if the ride has any hard stretches or goes beyond 90 minutes, you'll hit the wall. Fasting through intensity is a performance own-goal.

  • MISTAKEAttributing power fade to fitness and training harder.

    FIXFix fuelling first. Adding more training load on top of a ride where you're already depleted is how you end up overtrained without getting faster.

FAQ

FREQUENTLY ASKED QUESTIONS

How much should I eat on a 4-hour ride?
At 60g of carbohydrate per hour from 45 minutes in, a 4-hour ride needs roughly 200–220g of carbs. That's about 4–5 gels, or a mix of gels, bars and carb drink. Build up to this if you haven't been fuelling this aggressively — don't debut it on a race day.
Is power fade on long rides normal?
Some gradual drop in peak power over a very long ride is normal — fatigue accumulates. But a sudden or sharp fade after hour 2–3 almost always indicates glycogen depletion or dehydration, both of which are preventable.
Does base training prevent power fade?
Yes — better aerobic conditioning means your muscles burn a higher proportion of fat at moderate intensities, preserving glycogen stores for longer. Zone 2 training specifically develops this fat oxidation efficiency, extending the point at which glycogen becomes critical.
Can dehydration cause power fade?
Yes. A loss of just 2% of body weight through sweat (1.4 kg for a 70 kg rider) measurably reduces power output by 5–8% and increases perceived effort significantly. Drink before you're thirsty on long rides — roughly 500–750ml per hour in normal temperatures.
Why do I fade more in the heat?
Heat increases fluid and glycogen burn rate simultaneously — you sweat more, cooling effort diverts blood from muscles, and cardiac strain goes up. Hot rides require both extra hydration and earlier, more frequent fuelling than equivalent rides in cool conditions.

RELATED EPISODES

HEAR THE CONVERSATIONS

RELATED TOPICS

STILL GUESSING?

A coach removes the guesswork.

Apply for Coaching