Weird Science: Is fast food as effective as sports supplements for post-workout recovery?

The Scientist

In a market saturated with energy gels, recovery drinks and protein snacks, it’s easy to assume that science has all bases covered as far as sports nutrition is concerned. Dr Brent Ruby is challenging convention with studies into the effects of fast food on post-workout recovery, uncovering fascinating results…

‘It’ll sting at first,’ says Dr Brent Ruby as he slides the needle under my skin. Within a minute, the local anaesthetic has rendered my outer thigh so numb that I don’t feel his scalpel cutting down to the muscle. ‘Walt’s going to suck it out,’ says Ruby. Walt is Walter Hailes, Ruby’s colleague. ‘It’ is my flesh.

Ruby is an exercise physiologist at the University of Montana in the US and director of a research centre dedicated to maximising human performance. He’s a charismatic, Ironman-competing, cowboy-hat-wearing grinner, partial to fast runs and surfing on stand-up paddleboards he crafts by hand. I’ve volunteered as his human pincushion because over the last 15 years Ruby has made a name for himself thanks to and, sometimes, in spite of, his creative, contrarian approach to questions about the human body’s capacity for endurance and recovery.

The Method

The study that has me squirming under the scalpel is classic Ruby. He explains that a lot of research work in recent years has studied how we should refuel for optimal recovery after hard workouts, creating a big industry in response. ‘I don’t buy it,’ he says. The body has evolved to be very clever, he says; it can quickly grab and utilise the macronutrients it needs – carbs, protein, fat – even from seemingly low-quality food. Which explains the bags of McDonald’s congealing in the other room.

‘We decided to go to the extreme and try the foods that people don’t consider to be recovery foods at all,’ he says. ‘We wondered if it would have the same impact in terms of muscle recovery and performance.’

To test the hypothesis, he and his colleagues are exhausting guys like me on stationary bikes, feeding us two fast-food meals as we rest, then comparing our performance on another ride a few hours later with our performances on another day when we recover using sport supplements.

Ruby clearly relishes throwing
 a spanner into the works
 of conventional thinking by
 bringing Ronald McDonald to 
the training table. ‘There’s the
 strategy of just falling in line
 and becoming a good consumer 
of the research that’s been done
 for many, many years,’ he says.
 ‘But my mind is not the typical scientist mind. It is riddled with the desire for creativity and poetry and imagination.’ The scientific method may be rigid, but the questions you ask don’t need to be, he says.

Back in the lab, Ruby pushes the cartoon needle into my thigh. Hailes pulls on a suction plunger and a tiny pink blob quivers in a petri dish: human sashimi. These biopsies give a snapshot of what’s happening in the muscle at that moment, including how much glycogen it contains, ie how much fuel is in the tank.

Ruby crochets a stitch in my thigh and slaps on a bandage. Another victim is waiting for his meat to be harvested. And I’ve got a date with some hash browns.

The Study

After my biopsy and McBreakfast, I talk to Ruby about the study. He’s interested in quick muscle recovery, the kind that lets a tired soldier or a hard-core athlete get up and push hard again, fast. That sort of recovery is more complicated, yet also simpler, than nutrition-product makers would have you believe, Ruby says. Work in his lab has shown that the environment in which your muscles recover plays as big a role in their refuelling as what you eat after that 10-miler. His team has teased out the ideal conditions for fastest recovery: keep the body cool, but keep the exhausted muscles warm. That’s nearly impossible, says Ruby.

Years of running wisdom seem to be detonating around me. ‘Shouldn’t I be drinking chocolate milk,’ I say, ‘while standing in a cold river...’

‘ compression socks!’ he giggles.

Make no mistake: Ruby isn’t arguing that you should follow every run with fast food. But you could, in a pinch.

‘So what do you do after a hard workout?’ I ask him.

‘I never obsess about it, hardly ever,’ Ruby says. ‘And I obey my cravings.’ He eats real food– some protein, some carbs. The occasional doughnut. He rarely touches the highly engineered stuff.

Two hours after my post-cycling meal of McDonald’s pancakes, hash browns and orange juice, I sit down to a hamburger and fries. Two hours after that, Ruby skewers me once again to gauge how much glycogen my muscles have re-synthesised. Then I’m put on the same stationary bike to grind out a 20K time trial as fast as possible. It’s a grim, panting 34:47.

A week later I return to campus and do it all over again; I’m fed the same macronutrients but from sport supplements this time. That afternoon I pedal away on a second time trial. It doesn’t feel any easier.

The Findings

Weeks later Ruby shows me the results: on my second ride, I finished four seconds slower than I did when I was fuelled by McDonald’s. Initial study results showed that both diets produced similar time-trial results in the riders, says Ruby, though he cautions that the study hadn’t been finalised. ‘I would like the take-home message to be that recovery foods come in all shapes and sizes, and they are often more widely accessible than a lot of these engineered sports supplements,’ Ruby tells me.

How will the study be received? ‘I anticipate that there will be folks within the field who say it sends the wrong message,’ he replies. ‘Well, then, you’re reading it wrong.’

Ruby can’t wait to take these results to the people. ‘I’ll be bringing this up every chance I get,’ he says. ‘It’s the ultimate way to present what you need to take in to recover adequately. Muscle recovery isn’t as complex as people think and sensible combinations of macronutrients from a wide range of possible sources can work as well as, or better than, engineered products.

‘Everyone understands McDonald’s,’ Ruby says. ‘And everyone thinks, “Ooh, do I dare?”’ And then he laughs.

Speed Science

Find out how Ruby’s studies could make you a better runner.

Skin temperature

In a 2010 study, it was found that skin temperature and percentage of body fat better indicated finish time than VO2 max and percentage of body fat recreational female marathon runners.

The takeaway: To maximise performance, keep your skin cool by wearing sunscreen, less kit or white clothing.

Altitude training

In a yet-to-be-published study, test subjects who exercised in a lab and then rested at a much higher elevation than they were used to showed diminished potential to adapt and increase their fitness level.

The takeaway: Defying received wisdom, Ruby says don’t altitude train unless you plan to race at altitude.


Ruby’s team tested cyclists for overtraining markers over 21 days and 2,000 miles. Though such markers appeared, the cyclists’ time-trial times stayed constant or improved.

The takeaway: If you’re fit but tired, don’t ease training intensity: add more recovery, sleep more or address factors such as work stress.

Slushy hydration

Ruby is now studying whether drinking an ice slushy during exercise in very hot weather slows down the body’s rise in temperature.

The takeaway: If proven to work, a slushy could help a runner feel better and keep going – it could be offered alongside water at aid stations in hot races.