Nutrition For Cyclists: Why It Matters
Macronutrients for Cycling (Carbohydrates, Proteins, Fats)
Carbohydrate Intake
The ‘fuel’ element of the three levers is carbohydrate, which is also one of the three macronutrients in nutrition. It’s true that carbohydrates are king for fueling endurance performance and play a crucial role in supporting your recovery.
Carbs are the main source of fuel used during exercise and help you perform at high intensities, over long durations. Without enough (or without proper digestive preparation), you’ll be leaving energy on the table.
Glycogen is the primary source of carbohydrate your body relies on at the start of exercise. Made up of long chains of glucose molecules, glycogen stores are found in your muscles and liver. You can think of it as your body’s energy “checking account,” while fat stores act more like your long-term “savings.”
Just like the funds in most people’s everyday bank accounts, glycogen is limited. After 90 to 120 minutes of intense activity, your stores can be significantly depleted, which can have a noticeable impact on performance.
Carb Loading During Exercise
That’s why consuming carbohydrates - through drinks, energy gels, bars, or other carb-rich foods - during prolonged exercise becomes either beneficial or essential. Fat simply can’t support the high intensity needed for fast, sustained efforts like racing.
Carbs consumed during activity are called "exogenous" fuel - extra energy you bring in while you're spending it at a high rate. A carbohydrate snack tucked in your bib shorts or a carbohydrate drink stowed away on your bike can be just the thing to help you max out your cycling performance.
Due to their powerful impact on performance, exogenous carbs have been the focus of decades of research and experimentation.
Hitting the Right Carbohydrate Intake
Fortunately for today’s athletes, this research has led to well-established, evidence-based guidelines on how much carbohydrate to take in to perform at your best, depending on the intensity and length of your workout - despite all the noise and marketing gimmicks in the sports and cycling nutrition world.
Now, even when you’re not in the middle of a training ride or race, you still need carbohydrates, and they’re particularly important for preparation and recovery. So even if you’ve fueled well on the bike, don’t neglect the re-fueling to make sure you’re ready for the next go. A recovery drink, energy bars and energy gels can all really help your muscles recover away from the bike.
Protein
The priority is to fuel with carbohydrates during training and racing, partially because in comparison to fat, protein and fibre, which are more commonly associated with GI distress during exercise, simple carbs put a relatively low amount of stress on your gastrointestinal system.
And, carbs are ‘protein sparing’, enabling you to worry less about your body breaking down muscle protein during exercise.
But protein still does play a vital role in your overall health and performance as a cyclist.
Whereas carbs can be stored in the body (as glycogen), we can’t hold onto unused protein and save it for a rainy day. It’s automatically broken down and used to build things, which means we need to make sure we have enough building materials for whatever projects are on deck.
Using Protein for Muscle Repair
As an athlete, those projects are your muscles and the work you’re expecting them to handle through training and racing. When you consume a protein source, it gets broken down into amino acids. As my science teacher used to drill into me, “amino acids are the body’s building blocks”.
We need building blocks to replace worn out cells and help make new ones, as well as maintain and repair tissues, and support cellular tasks. Protein is also needed for hair, skin, nails, muscles, bones, cartilage, red blood cells, enzymes, hormones and antibodies. Clearly, it’s an important ‘life’ ingredient.
Some amino acids can be synthesised in the body, but nine of them (known as ‘essential amino acids’), have to come from your diet.
Research has moved towards recommending a higher protein intake for athletes, especially those involved in intense training, as insufficient amounts will lead to negative nitrogen balance, a sign of protein catabolism and slow recovery. If maintained, this increases the athlete’s risk of muscle wasting, injuries, illness and training intolerance.
Giving Your Body Enough Nutrition
At least 1.6 grams of protein per kilogram (or 0.73 grams per pound) of body weight per day is the recommendation based on the nitrogen-balance methodology, though higher amounts up to 2.5 g per kg may be appropriate during demanding training seasons. Additionally, injury recovery necessitates a higher intake of 2-3 g per kg (or 0.9-1.4 g per lb) to facilitate wound healing, tissue building and glycemic control.
Instead of having all of your protein during one meal or microdosing throughout the day, the optimal strategy is to consume approximately 0.25-0.55 grams per kg (or 20-40g absolute) of a high quality protein source evenly distributed across the day every 3-4 hours. This seems to be the best way to maximise muscle protein synthesis and counteract muscle protein breakdown.
Adding Protein To Your Cycling Diet
You don’t have to get stuck in the weeds of counting every gram for the rest of your life, but it’s worth considering whether your protein sources are really ‘protein sources’ or do they just contain protein?
My favourite example of this is peanut butter. To get 25g of protein, you’d need to eat ~7 tablespoons (112g) of peanut butter which delivers ~700 calories. I’m not telling you not to do this, but I’m guessing you might not be able to stomach that much on a regular basis. Even if you do, that’s only 25g of protein, and you’re likely going to need at least three times that amount per day.
Compare this to chicken breast, which delivers ~25g of protein in just 85g (cooked weight) for ~270 kcal. That’s just a few bites! A middle ground would be eggs, as four of them give the same 25g dose for ~285 kcal.
A 2023 paper tested the anabolic response between consumption of 100g and 25g of protein. Interestingly, the former led to a greater and more prolonged response in protein oxidation and synthesis compared to the latter. Realistically, it doesn’t mean you should have 100g of protein at every meal, but it does underscore the importance of consuming what you need at a meal even if it exceeds the now-mythical limit.
Putting your protein priorities into place with a cyclist's diet
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Total daily protein is the most important: ~1.6 to ~2.5 g per kg (higher end 2.2-2.5 for extra demanding seasons)
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Break down your total number into 3-5 servings
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Distribute those servings evenly(ish) throughout the day, such as every 3-4 hours
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Know your serving sizes. Weigh it out for a few times so you can see what an appropriate amount of your go-to protein sources looks like to hit your target
Micronutrients for Cyclists (Vitamins, Minerals, Electrolytes)
Vitamins and Minerals
As a dietitian, I always recommend getting bloodwork done to assess any existing micronutrient deficiencies. If you are low in vitamin D or iron, two of the more common ones for instance, then supplementing (alongside your practitioner) may be a helpful next step. However, you can typically meet your day-to-day needs through eating enough and eating nutrient dense foods. One of the biggest stumbling blocks to this that I see are when athletes neglect total energy intake (eating enough fuel) and/or struggling to eat a variety of foods. The now-cliche phrase of ‘eat the rainbow’ to cover a variety of nutrients in your diet is actually a pretty decent approach! And, it’s a good place to start.
Electrolytes
For the general population, getting enough electrolytes (namely sodium) is doable through a normal daily diet. However, for athletes – particularly endurance athletes – who are sweating a lot, it’s harder to recoup your losses since they’re mounting up so quickly. Sodium is such a critical part of hydration and an overall valuable nutrient.
It plays a key role in how your body functions, from maintaining fluid balance and cognitive function to helping the gut absorb nutrients, impacting nerve impulse transmission and supporting muscle contraction.
Importance of Sports Drinks
You lose electrolytes in your sweat, and most of this is sodium. Subsequently, sodium plays a crucial role in hydration, and using the strength of sodium-based electrolyte that suits how you sweat is a key piece of your race strategy. Some endurance cyclists lose more sodium in their sweat than others, but the ratio (sodium:fluid) for an individual stays fairly stable.
To figure out how much salt you need, look for your nearest Sweat Test Center – they’ll measure the relative concentration of sodium in your sweat and help strategise the appropriate concentration to put in your bottles. An electrolyte drink can help replace the sodium lost during races or training sessions, and keeping your fluids topped up is crucial to a solid hydration strategy.
