Carbs for a Race: How Many You Really Need (Before, During & After)

Featuring insights from Richard MSc, BSc, Food Scientist at Hummingbird Fuels

Endurance athletes hear it all the time: fuel matters. But knowing how much to eat and when to eat it can make or break a race. When athletes under-fuel, the dreaded bonk hits. When they time carbs correctly, performance feels smooth, strong, and steady. To get clarity, we spoke with Richard, the food scientist behind Hummingbird Fuels, a natural, high-carb drink mix designed to give athletes the energy they need without gut disruption. With a BSc in human physiology and MSc in food science, Richard spends his days developing fuel that is simple, effective, and backed by real science. This is his breakdown of carbs before a workout, carbs per hour running and cycling, how many carbs marathoners need, and how to refuel afterward.

Why Carbs Matter So Much in Endurance Sports

Your body stores both fat and carbs for energy, but not in equal amounts. Fat stores are huge and nearly endless. Carbohydrate stores are small. Most athletes only carry about 60 to 90 minutes of usable carbohydrate energy in the tank. Once that tank drains, performance drops fast. Richard explained that this is why consistent intake during exercise is essential:

“As your body storage decreases, the carbs you consume are used immediately to turn into energy.”

This is the entire reason products like Hummingbird Fuels exist. They supply the exogenous carbs your body needs to maintain power output hour after hour.

Before Your Workout or Race: How Many Carbs You Really Need

Timing: The 90 Minute Rule

One of the biggest mistakes athletes make is eating too close to the start. Richard recommends leaving at least 90 minutes between your final meal and the race. Eating too close causes insulin to spike, which can divert carbs into storage at the exact moment you need them available for energy.

What to Eat

Your pre-race meal does not need to be fancy. Just aim for familiar foods:

• About 40 grams of carbohydrates
  

• About 20 grams of protein
  

• A little fat
  

• About 5 to 6 grams of fiber
  

Think oatmeal with fruit, toast with nut butter, or your normal breakfast routine.

During Your Race: Matching Carb Intake to Your Effort

This is where many athletes under-fuel. The harder you go, the more carbs you burn and the more you need to replace. Richard emphasized that carb needs depend heavily on power output and pace, not just distance.

Cycling such as gravel or endurance rides

• Average athletes: 80 to 100 grams of carbs per hour
  

• Competitive riders producing 250 to 260 watts: 100 to 120 grams per hour
  

Running and Marathons

• Four hour marathon: about 80 grams per hour
  

• Three hour marathon: about 120 grams per hour
  

• Elite and sub-elite: up to 120 to 160 grams per hour
  

These numbers align with the trend among top endurance athletes who now consume 100 to 120 plus grams of carbs per hour during peak racing. That is why Hummingbird Fuels is formulated as a high-carb drink mix that is gentle on the gut. It helps everyday athletes hit these higher, evidence-based intake levels without discomfort.

Richard put it simply:

“You want to match how much you eat to how much you burn.”

Most athletes are burning far more than they realize.

After Your Workout: Rebuild and Restore

Once the race or long workout ends, focus immediately on refueling. A simple guideline:

• 20 to 25 grams of protein
  

• 35 to 40 grams of carbohydrates
  

• Add fruit or vegetables when tolerable
  

Then resume your normal daily nutrition pattern. Early refueling helps replenish glycogen and supports recovery, especially after long or intense efforts.

Common Fueling Mistakes to Avoid

Richard sees the same fueling mistakes often. These are the big ones to watch out for.

• Eating too close to the start: Elevated insulin steals the carbs your muscles need.
  

• Waiting too long to take in carbs: Start fueling as soon as you start moving.
  

• Stopping fueling in the last hour: The carbs you take late in a race support recovery and a strong finish.
  

• Trying to catch up after the bonk: Once you bonk, you cannot take carbs and instantly bounce back.

“It takes a while for those carbohydrates to get back to your muscles.”

It is far better to stay ahead than dig yourself out.

Why Hummingbird Fuels Helps Athletes Stay Topped Off

Most athletes want to hit 80 to 120 grams of carbs per hour, but struggle because gels, chews, or sugary mixes can cause GI distress at high volumes. This is exactly why Hummingbird was created. Richard and Lisa, founders of Hummingbird Fuels, formulate each mix to:

• Deliver high carb density for long races
  

• Use natural ingredients that digest easily
  

• Provide clean, smooth taste for sustained sipping
  

• Support steady fueling without gut issues
  
  

Whether you are a runner, cyclist, triathlete, or marathoner, Hummingbird Fuels makes it easier to meet your fueling needs and perform at your best. Explore our high carb drink mix flavors today!