Carbohydrates fuel the engine for high-intensity efforts like nailing that one in four, (good) fats fan the furnace during easier, stamina-building efforts and protein. Where exactly does protein fit into the road cyclist’s macronutrient equation? Isn’t it all tubs of white powder that enlarge a bodybuilder’s extremely tanned visage? Well, no. Here, we tap into the input of a world-leader in protein metabolism and one of the WorldTour’s finest nutritionists to lift the lid on your building blocks to more speed.
Essential amino acids
Dr Paul Morgan is a senior lecturer in human nutrition and metabolism at Manchester Metropolitan University, England. Although his work increasingly focuses on clinical populations and understanding diseases like muscle dystrophy, he continues to work with elite athletes, where his work always starts with the fundamentals.
“Protein is simply a vehicle to provide essential amino acids,” he says. “There are 20 amino acids, nine of which we call ‘essential’. These are the ones that we can’t synthesise in the body through non-amino acid precursors. Well, we can but to a very small degree – about 1% of daily requirements. So, we have to consume these in our diet.”
This constant need for essential amino acids is down to the perpetual turnover of tissue protein; in fact, turnover rates are higher in more metabolically active tissue like the liver, pancreas, kidney and plasma and lower in the brain and skin.
Muscle tissue is labelled less metabolically active but arguably not so for athletes, for whom the turnover is greater than sedentary folk. “This is the main ‘known’ reason for consuming protein in that when you exercise, proteins are broken down from the muscle tissue because they’re deemed faulty,” says Morgan. “You then consume protein to not only repair these broken tissues but to rebuild stronger. That rings true for all athletes, including endurance cyclists, because you obviously use your muscles a lot.”
This remodelling process of skeletal muscle protein happens to us all, even if you don’t possess the peak power output of a top sprinter like Dylan Groenewegen, who can generate over 1500 watts when powering to the line. Groenewegen and his teammates, including Tour challenger Ben O’Connor, will be well aware of this remodelling as their performance dietitian, Santiago Fernández Pola, is a protein authority. He picks up the protein story on its myriad benefits to road cyclists.
“Dietary protein increases muscle glycogen resynthesis under sub-optimal carbohydrate conditions,” he says. “This is important for riders who can’t tolerate high levels of carbohydrates after a ride. And we mustn’t forget about the mitochondria. These are the powerhouse of the cells and their role is central to endurance performance. Like myofibrillar proteins – proteins within the muscle cells – they comprise different proteins. These are damaged during endurance exercise and must be replenished. Healthy mitochondria is the cornerstone for endurance performance.”
Protein also keeps your immune system working proficiently, playing a central role in reducing the risk of bacteria or viral infections, and strengthens bones, which is particularly important in the cycling cohort.
“Due to the lack of osteogenic stimuli (e.g. resistance training or high-impact activities), cyclists experience on-the-bike bone resorption, i.e., breakdown,” says Pola. “The outcome? Brittle bones and a high risk of fractures. Collagen, a protein found in connective and bone tissue’s extracellular matrix, may contribute to preserving or even increasing bone mineral density, provided the osteogenic stimuli are present. It’s why collagen supplementation may be useful for cyclists who rack up large mileage.”
Post stage nutrition at the 2025 Lloyds Tour of Britain Women (Image: Alex Whitehead/SWpix.com)
Key amino acids
It’s clear that protein’s role in an athlete’s body is much more than bulging those biceps. But digging deeper, we know that amino acids are protein’s building blocks with each performing a different role, so are any of greater importance to optimum pedalling than others?
“Among the repair, remodelling and metabolic benefits, we find the cardiovascular ones and these are mainly linked to a particular amino acid called ‘arginine’,” says Pola. “Arginine contributes to better blood circulation by supporting nitric oxide production, which dilates blood vessels and improves oxygen and nutrient delivery to the working muscles, potentially enhancing performance.” Arginine can be found in meat, fish, nuts and seeds.
“Although every amino acid must be present for optimal muscle protein synthesis rates, there’s one that deserves more attention,” adds Pola. “That’s leucine. This amino acid switches on the metabolic pathways governing muscle protein synthesis, which is the process that underpins muscle repair and growth. That’s why you should include leucine-rich proteins in every meal.”
The richest sources of leucine are meat and poultry with chicken breast, beef and turkey good options. Fish such as tuna, salmon and cod are also excellent sources, as are dairy products like milk and cheese. Whey protein, a byproduct of cheese production, is especially rich in leucine, which is why it’s commonly used in protein supplements.
For those familiar with protein, there’s a feeling that vegetarian and vegan riders suffer from insufficient leucine intake because it’s an “animal amino acid”. But that’s been partly dispelled with relatively recent research suggesting the humble spud contains a similar percentage of leucine as milk, eggs and meat. That said, you’d need to consume much more potato than meat to enjoy similar anabolic effects.
There’s a difference in the quality of protein between animal-based and plant-based eaters. “Protein quality is a term that the field has coined and relates to the amino acid composition of the dietary protein and its digestibility,” says Morgan. “Higher-quality proteins have higher amounts of essential amino acids and also have good availability of all nine essential amino acids.
Read More: Supplementing peak performance: What the pros use
“The literature reveals that animal-based proteins are superior in terms of all-round quality than plant-based proteins, at least through the lens of this pure definition. They more closely match the mean essential amino-acid content of the human muscle.”
If you’re a vegetarian or vegan cyclist, make beans and lentils a staple, and don’t fear topping up with a pea protein powder or similar.
That raises the question of how much protein an active road cyclist needs each day to replenish and rebuild? For recreational riders, you’re looking in the region of 1.4 to 1.7g of protein per kilogram bodyweight, so between 98g and 119g per day for a 70kg rider. For the elites, Pola says this cranks up to around 2g to 3g protein per kilogram bodyweight per day, so between 140g and 210g for a 70kg rider.
“We distribute this over four to six meals per day,” says Pola. “As an example from the Tour…
“Breakfast This will vary according to individual preferences and stage’s starting times (the earlier the start, the more the focus will be on carbohydrates and the less in protein): eggs in the form of omelette, scrambled or boiled; low-fat yoghurts; whey protein powders.
During the stage No protein.
Immediately post-stage Recovery shake with 35g whey protein isolate/concentrate blend.
Post-stage meal Lean protein sources such as white meal (chicken/turkey); low-fat cottage cheese; Greek/protein yoghurt.
Dinner Type of protein chosen will depend on parcours of the next day’s stage. Usually, before an individual time trial and mountain stages, we prioritise the inclusion of easily digestible proteins such as white fishes or meats, avoiding red meats.
Snacks (late afternoon and before bed) Low-fat Greek yoghurt, protein yoghurt or whey protein isolate.”
A protein-rich breakfast is important for performance (Image: Getty Images)
Importance of active reservoir
This drip-feeding of protein-rich foods throughout the day is common for both elite and amateur riders for a very good reason. “Protein is the only macronutrient in the body that doesn’t possess an inactive reservoir,” says Morgan. “What I mean by that is that glycogen sits in the muscle and unless you use it, it does nothing. Fats are the same. Yes, it might keep you warm but it’s essentially inactive unless you burn it off.
“We don’t have that for protein; there are no inactive resources to call on when the body needs it. While we know muscle is important, if the body desperately needs amino acids during, say a period of fasting, it’ll draw on these resources from the least critical area, which ultimately would be muscle tissue over, say, cardiac tissue.
“I mention that because this inactive reservoir ties in with optimising your rides. Research shows you enjoy a nice muscle-building response to a dose of protein, then during a period of ‘fasting’ – we’re only talking about small periods like two to three hours as you would between meals – the rate of muscle building starts to decline. That’s because muscle building is a really energy-intensive process, so it makes sense for the body not to want to continue that process indefinitely. So, we see this spiking of muscle building and dropping during the day.
“You might then ask why should you just not graze high amounts of protein all day? Well, that’s down to something called the ‘muscle full effect’ and stems from studies out of Nottingham University. They showed that if you consume a big dose of protein – say 40 to 50g like elites would consume per meal – and then an hour later you consume another 40 or 50g protein, the muscle doesn’t respond to it. It becomes almost acutely resistant to the anabolic stimulus, which we think links back to that energy-expending element.
“That’s where the whole notion of the distribution across the day comes from, as it gives you a period of time between each meal for this retracted period to disappear. Also, practically that’s the way elite athletes need to eat because not only do they need high amounts of protein but they could be training several times a day.”
Recreational riders should also follow this template of protein feeding at reasonably regular intervals, albeit be aware that ideally the amount of protein consumed fluctuates depending on several other factors.
“We tend to give a range of protein requirements because it tends to be higher on days where riders perform strength or hard interval efforts,” says Pola. “In addition – and as counter-intuitively as it sounds – recent research suggests that protein requirements should be even higher during recovery days. You might also need more protein if you’re training fasted or glycogen-depleted.
“During periods where athletes are seeking optimum body composition, an increased dietary protein intake may also prevent excessive muscle loss, helping cyclists maintain lean body mass while reducing body fat. It also increases long-term satiety, allowing the rider to achieve a small/moderate energy deficit while feeling full over the day.
“Further, at an elite level, protein requirements are highly individualised and role specific, which often comes down to body mass impacting protein needs. For instance, sprinters, lead-out riders, all-rounders and domestiques tend to be more muscular and thus heavier than climbers. In absolute terms, the heavier you are, the more protein you require to guarantee an optimal muscle remodelling and recovery process. That said, in relative terms, it’s pretty much the same most of the time.”
Does this vary if you’re a female rider? In relative terms, it’s pretty similar, says Pola. “However, hormonal factors associated to menstrual cycle seem to play a role in protein needs. During the luteal phase – post-ovulation, before menstruation – progesterone levels rise and the oestrogen:progesterone ratio is low. This phase is characterised by higher amino-acid oxidation rates. Because of this, female athletes may require more protein in the luteal phase to compensate for increased breakdown.
“In the mid-follicular phase, the period after menstruation and before ovulation, oestrogen levels are higher relative to progesterone. High oestrogen reduces amino-acid oxidation, meaning protein is spared as an energy source. As a result, protein requirements may be lower during this phase. However, research is in its infancy and more experimental data is needed before firm guidelines can be established.”
Post stage nutrition at the 2025 Lloyds Tour of Britain Women (Image: Alex Whitehead/SWpix.com)
To shake or not to shake…
Okay, you’ve packed your fridge with organic chicken breast and fish; your Kilner jars are bursting with seeds and nuts; and you’ve enough milk to send Yeo Valley’s shares sky-rocketing. But this is the real world. You’re balancing riding with life, the universe and everything. Do you have time for protein-rich meals after every ride? Should you add protein powder to your next Ocado shop? What do your riders do, Pola?
“Sometimes they consume them, sometimes they don’t. Protein consumption right after exercise depends on: the type and duration of the training session, and how much time there is between training and lunch.
“After low-intensity sessions of fewer than three hours, if lunch is taken within an hour-and-a-half, a protein shake’s not deemed essential. After a moderately long ride of over three-and-a-half-hours that contains intervals, a protein shake’s beneficial to kick-start recovery.
“Aim for a shake that contains essential amino acids, is easily digestible and leucine-rich to achieve a fast and robust muscle protein synthetic response. Our partner is 6d Sports Nutrition and their whey protein isolate blend is great.”
Assimilate those short and moderately long rides to your own abilities to determine whether a shake is required.
Pre-sleep feeding?
As you can see, when it comes to protein intake, there’s much to think about; in fact, it’s rather exhausting. You probably need to slip into your pyjamas and catch a bit of shuteye. Well, if you do, before you doze off, take note that there’s research by Professor Luc van Loon that suggests sleep should be preceded by a whacking great hit of protein to optimise muscle protein synthesis rates .
“Luc works at Maastricht University,” says Morgan. “They’ve undertaken pretty cool research that’s involved fitting subjects with nasal tubes so they can feed them through the night. They’ve also woken them up for muscle biopsies. It’s crazy.
“Those guys have shown positive effects on protein turnover during sleep. Practically, unless you want to fit a nasal tube and be fed overnight, that means consuming a slow-digesting protein like casein before bed.
Read more: How food timing before a ride might be impacting your performance
“But I feel the jury’s still out on that one. I’ve got a working hypothesis – so not backed up by science – that we should leave sleep alone. It’s a time of repair and rebuild, not for breaking down foods. You might increase muscle building but is at a cost to other mechanisms at work during sleep? There’s also the toilet aspect. If you eat late, there’s a good chance you’ll awake needing the loo. That could affect your general recovery.”
For now, we’d leave the nasal tube for the universities and stick with the regular feeding. Instead, focus on a sound protein plan that’s packed with leucine-rich foods and broadly hits your daily requirements. Do that and your muscle, mitochondria and metabolism will be very happy.