Exercise nutrition isn’t rocket science, but it’s not as simple as finger painting either. A bit of knowledge is required to fuel your rides properly. Many cyclists fail to fuel correctly, and it does make a difference. Here are the key facts and guidelines every cyclist should know.

The two primary purposes of exercise nutrition are hydration and energy provision.

Perspiration is the body’s cooling mechanism. Sweating helps regulate the body’s core temperature. Sweat contains both water and electrolytes. The more water and electrolytes the body loses, the less effective this cooling system becomes. At the same time, the efficiency of cardiac and motor signaling decreases, and the risk of muscle cramping increases.

As little as a 1% loss of body fluids can negatively impact endurance performance. For a 160-lb cyclist, this is about 1.5 lbs. of fluid loss.

Cyclists typically sweat at a rate of 900-1,200 ml per hour, though actual sweat rates can vary based on weight, intensity, air temperature, and genetics. Cyclists should aim to replace fluids containing both water and electrolytes (sodium, chloride, potassium, and magnesium) at a similar rate. Studies show that maintaining this balance has a strong positive effect on performance.

Carbohydrates are the primary source of energy for muscle contractions during cycling. Cyclists typically burn at least 200 grams of carbohydrates per hour while riding. The body can only store enough carbohydrates to fuel three to four hours of moderate-intensity riding.

Studies have shown that consuming carbohydrates during exercise lasting 60 minutes or more can significantly enhance endurance performance. However, the average cyclist can only absorb around 70 to 80 grams of carbohydrates per hour, so aiming for this amount is ideal.

It’s important to consume nutrition in an easily absorbable form during exercise. Most sports drinks are formulated to provide a balanced mix of water, electrolytes, and carbohydrates for quick absorption.

Insulin is a hormone responsible for transporting carbohydrates into muscle cells. The pancreas automatically releases insulin in response to rising blood glucose levels. Protein also stimulates insulin release. Research has shown that adding protein to a sports drink increases insulin release, which helps deliver carbohydrates to muscle cells more quickly. This allows muscles to conserve their stored carbohydrates, extending endurance.

However, too much protein in a sports drink can slow stomach emptying and hinder the insulin effect. The optimal ratio of carbohydrates to protein in a sports drink is 4:1. This ratio maximizes insulin release without slowing digestion.

Many cyclists don’t realize that protein is also broken down for energy during exercise. The longer the exercise, and the lower the body’s carbohydrate supply, the more protein is used. After about 90 minutes of intense activity, as much as 15% of the energy used by muscles comes from protein. Most of this protein is derived from the breakdown of muscle cells.

Consuming protein during exercise helps accelerate muscle protein rebuilding after exercise and may also reduce muscle protein breakdown during exercise.