Runners need carbohydrate for energy. Runners need protein for muscle repair. Heard this before? Me too. Grand. So I eat lots of carbs and lots of protein and walk around my little day thinking in my little runner head that I’m doing all the right things to get my running form on its merry way. Not so.
Most people probably already get enough protein in their diet without even knowing it. Most runners do too. In fact, most are likely consuming far more than they actually need.
The Protein Breakdown:
Protein is one of three macronutrients, the other two being carbohydrate and fat, which provide us humans with energy, or calories, essential to sustain life. Each gram of protein provides 4 calories of energy and makes up approximately 15-17% of a person’s body weight.
What is Protein? Protein is made up of organic compounds called amino acids. There are 20 amino acids, which can be strung together in different sequences and lengths to form different proteins and it’s this amino acid structure that differentiates one protein from another. For example, the amino acid sequence of an egg white is different from that in the protein in a glass of milk.
Amino acids are often referred to as “the building blocks of proteins”, with proteins being the building blocks of muscle mass. Of the 20 amino acids that your body uses to make body proteins, there are the ones you eat and the ones that your body makes. Those that your body cannot make are called “essential” because they have to come from your diet. There are 9 of those rebellious aminos.
The Rebels (ie. essential amino acids): histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.
Most proteins don’t contain all 20 aminos. Proteins that contain all 9 essential aminos are referred to as “complete” proteins and these include animal sources – meats, fish, poultry, eggs, milk and milk products. Plant proteins found in foods like beans, lentils, nuts and whole grains and – with the exception of soybeans (and food derived from soy) lack one or more essential amino acids, so they’re considered “incomplete”.
Why Do We Need Protein?
Protein is crucial to the regulation and maintenance of the body and plays a role in blood clotting, fluid balance, hormone and enzyme production, and cell repair. DNA structure, cell formation, enzymes (proteins which make everything happen, e.g. break down food for absorption; regulate the entry of nutrients through cell walls, and the removal of waste-products; to grow, develop, move, reproduce…), haemoglobin (the protein which, with iron, carries oxygen around your body), myoglobin (protein in muscle fibres), bones, the production of antibodies, which circulate in your blood to protect you against viruses and keratin which forms your hair and nails… It’s important, got it?
How Much Protein Do We Need as Humans?
The Institute of Medicine (US) recommends that 10-35% of daily calories come from protein;
The World Health Organization recommends that only 10 % of daily calories needs to come from protein to maintain health;
The International Society of Sports Nutrition (ISSN), recommends that exercising individuals should aim for protein intakes of 1.4-2.0g / kg per day, while endurance athletes should err on lower end, intermittent sport athletes (e.g. soccer) in the middle and strength athletes on the higher end;
Runners Connect note that the amount of protein a person needs when they are not training is .8 grams per kilogram of body weight.
So what does that mean? If I weigh 59 kg, I have a basic need of 47g of protein every day. To give you a real idea of what that looks like, a 200g portion of fish is about 39g of protein; a 200g fillet steak is 42g of protein; and a 200ml glass of skimmed milk is 7g of protein. So, if you had your steak and a glass of milk in day, you’d already have enough.
High protein diets have been a topical issue of debate in the media in recent years, with concerns being voiced about possible resulting health risks. Kidney problems, constipation and an increased risk of heart disease among them. But even if you take all of that away, more recent studies would suggest that your body can only actually use a certain amount of protein at any one time and if you go above and beyond this, your body simply cannot put it to use effectively and will either (a) get rid of the excess out of your body as waste or (b) convert it and store it as fat or eventually (c) use it as an energy source- my understanding it that it’s the last source of energy that your body will revert to as a source of energy because of the difficulty in breaking it down and will always look to carbohydrates as its first source of energy, before then moving on to fat.
If you’re in the UK (or are creative on the internet 😉 ) you may have seen the BBC programme Trust Me, I’m A Doctor. I don’t believe everything I see on Telly but this was really interesting and really worth a watch. In Season 4, episode 4, Dr Chris Van Tulleken conducted an experiment in which he investigated whether consuming extra protein after exercising actually increased his muscle mass.
Focusing on whey protein, they recruited 24 volunteers (aged 20 to 67), put them on an 8 week weight-lifting programme. After each session each volunteer consumed a drink containing either 20g of whey protein or 20 g of maltodextrin (a carbohydrate which acted as a placebo). Neither they, nor the scientists involved, knew which drink they were getting. Lifting capacity, lean body mass (using a body composition chamber), knee strength and thigh muscle thickness were measured at the beginning and end of the experiment.
After the 8 weeks, all the participants became stronger. On average:
Lifting capacity increased 33%
Knee strength increased on average 31%
Lean mass increased 1%
Thigh muscle thickness increased 4%
BUT, they found that there were no significant differences between the protein and the placebo groups. What they found was that taking the protein supplements had NO EFFECT on strength or muscle growth.
Dr Chris found, in conducting this experiment that in a window of approximately four hours, our bodies can only use around 20-30 grams of protein (depending on the lean mass of each individual). Of this, a mere 2 grams can be used to repair muscle. Any additional protein will be burnt as energy, stored as fat or excreted in urine. They concluded that if you’re healthy and eating a balanced diet, then spending money on protein shakes or supplements in the hope of building more muscle is a waste of money and that ultimately, you’re basically just peeing away expensive urine (sorry to be crass).
How Much Protein Do We Need as Runners?
But if I’m running miles every day, every week, breaking down muscle proteins and damaging muscle fibers, don’t I need more protein to help my muscles repair and recover?
According to Runners Connect, protein requirements do increase when you embark on endurance or resistance training and if you fail to consume enough protein when training hard, your body will break down muscle to fuel your body on training runs. The goal with running is to build and maintain lean muscle mass, not break it down for fuel.
RC note that endurance training combined with the correct amount of protein will facilitate faster recovery and allow you to train harder on workout days by repairing and growing lean muscle mass. They say that getting enough protein to match the amount of running you do is important and that a typical diet doesn’t always supply enough protein for the serious runner.
The Runners Connect recommendation for optimal recovery during endurance training is 1.2 – 1.7 g of protein per kg of body weight, depending on both the intensity of a particular training day and the mileage you’re doing. They suggest monitoring your body response and experimenting with slight increases/ decreases in protein intake until you notice a positive difference in your recovery rate.
Putting It All Together:
As I have said so often before, I am not a nutritionist, a doctor or a qualified expert in sports science/ nutrition/ medicine. I am a lawyer and an amateur running hobbyist with an enthusiastic nerdy interest in running science and biology, trying to sift through the vast amount of information out there and make sense of it all. What I understand from the research I did reading lots of articles, blogs, magazines, books, studies and watching documentaries, is the following:
Humans need to eat protein. (paying attention, wasn’t I? 😉 ) .
Runners need to eat more protein than lazy humans (just kidding) non-runners.
The human body can only use around 20-30g of protein in a 4 hour window of time, of which, only 2 g can be used to repair muscle so knocking back a big protein shake or just generally eating lots of protein thinking that you’re helping your body build lots more muscle is rubbish. Consume more than 20-30g in this 4 hour (ish) window and you’re body will simply stored it as fat, excrete it as urine or burn it as energy.
Eat/drink smaller amounts or protein at more regular intervals throughout the day, rather than in big chunks, so as to ensure that you’re getting enough protein but without resulting in what I just said in no.3.
What do you think about the conflicting research, studies and opinion on high protein diets?
Do you follow a high protein routine when it comes to exercise and training?