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Football is no longer won and lost on the pitch. If you ask a performance nutritionist, it's won or lost in the fridge, cupboards and anywhere food is served to players. That's because nutrition and supplementation today is barely recognisable from the days when oranges were served at half-time and a bottle of whiskey was kept in the changing room to warm players up before a match.

But can an army of nutritionists and culinary experts really make a difference? Will the latest pills and potions improve a team's performance? Or does none of this matter in the beautiful game if you're genetically predestined to be a legend with the ball at your feet? Take for example Dino Zoff's admiration of Paul Gascoigne: "He ate ice cream for breakfast, drank beer for lunch ... But as a player? Oh, beautiful, beautiful. I loved that boy," the former Lazio manager said, according to ESPN.co.uk.

In exploring the evolution of nutritional science in sport, we examined how food in football has progressed since the days of counting calories and force-feeding players giant bowls of pasta. We also identified teams with a dietary advantage thanks to their culinary preparation during training and on matchdays and tried to quantify how much of a difference it makes.

Calories

A player's energy reserves for 90 minutes are determined long before he laces up his boots and steps foot on the pitch. That assessment is based on a field of nutrition called bioenergetics, which is the study of the transformation of energy in living organisms—basically, how players take calories from the food they eat and convert them into energy. This is simply ensuring calories in equals calories out.

Research published in the Journal of Strength and Conditioning Research that analysed the diets of young professional football players for one week found that despite eating 2,831 calories per day on average, "A mean daily energy deficit ... existed because daily energy expenditures exceeded that of intake." So, despite consuming that many calories, the players were still burning more than they were eating.

Why? Because unlike in many other sports, football consists of intermittent, repeated episodes of both low and high-intensity activity. Periods of walking and light jogging are coupled with sprints at maximal effort, training up to five days a week and a match at weekends. All this equates to a mountain of calories burned. This is why—again, on a basic level—although Gascoigne's diet would never be considered healthy or optimal, at least he was meeting his calorie requirements for the day.

His breakfast of ice cream was calorie-dense, and considering alcohol comes a close second to dietary fat in terms of its calorie density—roughly seven calories per gram—it's easy to see how he could have consumed more than the 2,831 calories mentioned in the Journal of Strength and Conditioning Research.

Carbohydrates

Many traditional sports nutritionists claim carbohydrates are a footballer's primary fuel source. What this means is training and matches should be powered with a plentiful supply of high-carbohydrate foods like pasta, cereals and rice, since it's these food choices that ensure muscles' energy reserves—known as muscle glycogen—are adequately full and able to continue to work at a fast pace.

For those who aren't aware of what happens to the body when it's completely depleted of carbohydrates and muscle glycogen, take a look at this video of the 1997 Ironman World Championship featuring Wendy Ingraham and Sian Welch. It's aptly titled "The Crawl," and you'll see why.

The Los Angeles Times reported in 2007 that over 40 years prior, Dr. J. Robert Cade had invented the first carbohydrate-enriched sports drink to "help the University of Florida football team stay hydrated and in turn inspired the multimillion-dollar sports beverage industry." It was arguably the first sports supplement. Research conducted by the Graduate Department of Community Health at the University of Toronto in Ontario analysed the impact 0.5 litres of a 7 per cent glucose (sugar) polymer solution 10 minutes before the game and at half-time had on a player's performance. The results: Muscle biopsies indicated the supplementation slowed the muscle glycogen depletion.

What this means is if you slow muscle glycogen depletion, you also slow the time it takes to fatigue. According to research by the Institute of Food, Nutrition and Human Health at Massey University in New Zealand, this in turn enables players "with compromised glycogen stores to better maintain skill and sprint performance."

These findings were supported by a second study—again conducted at the Institute of Food, Nutrition and Human Health—that examined the effect of ingesting a carbohydrate-electrolyte solution during the 90-minute Loughborough Intermittent Shuttle Test on football skill performance. Results revealed there was "a 3 per cent reduction in skill performance from before to after exercise in the carbohydrate-electrolyte trial, whereas in the placebo trial the decrease was 14 per cent." This led scientists to conclude "skill performance during the simulated soccer activity appeared to deteriorate in the last 15-30 minutes of exercise. However, providing 52 grams of carbohydrate during exercise showed a tendency to better maintain soccer skill performance than a taste-matched placebo."

This is why when heading into extra time—or even penalties—the winning team might not necessarily be the most skilled but rather the most fuelled. The club's water-carrier becomes the most valuable member of the squad, and the contents of each sports bottle could be the difference between a 3 per cent reduction in performance and a 14 per cent one.

Fats

But how did the Norwegian football team Stromsgodset win the league cup in 2013 for the first time since 1970 on a diet that was void of any large amounts of carbohydrates? Where was the 14 per cent reduction in performance? In fact, how was it that Health and Living News reported they "'steamrolled' their opponents during an impressive final 45 minutes" of their winning game?

"Fat" is the short answer. It's something Timothy Noakes—one of the most respected experts in the field of low-carbohydrate, high-fat diets—has been telling athletes from all sports for years.

This is because, according to research published by Nutrition Focus New Zealand Limited, "the number of grueling events that challenge the limits of human endurance is increasing. Such events are also challenging the limits of current dietary recommendations." Scientists concluded that although carbohydrate-loading has been a widely used performance-enhancing approach to nutrition for years, "there are some situations for which alternative dietary options are beneficial." One of those circumstances is perhaps best described in the journal Human Muscle Fatigue: Physiological Mechanisms. Scientists noted the energy needed to sustain exercise for longer periods of time comes from the oxidisation of two fuels: glucose—carbohydrates—and long-chain fatty acids.

What they found was the latter is arguably a more sustainable and efficient fuel source since it provides the "largest energy reserve in the body" and can supply enough energy to last five days. Typically, this approach has been thought to be useful for marathons and ultra-marathons, so in theory, it would mean fuelling a footballer for 90 minutes should be easy.

Caffeine

In 2017, it seems most clubs are thinking beyond calories, carbohydrates and fats and turning their attention to anything that will give them a competitive edge. In 2012, that something was caffeine, according to the Independent, which reported "England right-back Glen Johnson told BBC 5 Live after Wednesday's 1-1 draw with Poland that some of the players had taken caffeine pills before the postponed World Cup qualifier."

Rio Ferdinand tweeted at the time it had been prevalent in football for some time.

Testing positive for excessive levels of caffeine was removed from the World Anti-Doping Agency banned list in 2004. The supplement has since become one of the most used in sport. For good reason too, since according to research conducted by the Division of Sport and Exercise Science at the University of Luton, caffeine can reduce a footballer's perception to fatigue by stimulating the production of the neurotransmitter beta-endorphin.

Couple these findings with research published in the British Journal of Sports Medicine that showed taking caffeine with carbohydrates helped spare muscle glycogen stores by encouraging your body to burn stored fat as fuel, essentially saving your muscle glycogen for extra time or those maximal intensity sprints. This is why James Collins, who is Arsenal's nutrition expert and held the same title for England at the last World Cup, was quoted in the Telegraph in 2015 saying, "Players will only use carbohydrate or caffeine gels in a match if they have practiced using them in training. We know that getting this right at half-time can have a big impact on energy levels later in the second half."

Beetroot

Following Leicester City's historic league win in 2016, the BBC published an article titled "Leicester City: The science behind their Premier League title." Within it, Leicester was noted to have "suffered the fewest injuries" in the Premier League, according to Physioroom.com, despite limited resources and a fast counter-attacking game. The article also mentioned that, "according to scientists at the University of Exeter, drinking [beetroot juice] improves sprint performance and decision-making."

Research in the European Journal of Applied Physiology found "beetroot juice supplementation attenuated muscle soreness" in "recreationally active males." It also stated "further research on the anti-inflammatory effects of beetroot juice are required to elucidate the precise mechanisms."

Next, according to the American College of Cardiology, just "one week of daily dosing [with beetroot juice] significantly improves submaximal aerobic endurance." It's worth noting this study featured elderly test subjects, but it has since been supported by published work in the International Journal of Sports Physiology and Performance, which tested elite rowers.

So, those small shots of vegetable juice have the potential to reduce muscle soreness and increase stamina. Also, Leicester City's success shows maybe sports nutrition doesn't have to be quantified and proved. Instead, just a willingness to test and trial new methods could pay dividends.

The Future

As is obvious from the aforementioned research—and real-life case studies—nutrition in football is evolving. It's far from an exact science, though, which is why as the sport develops, so should each team's approach to nutrition. Arsene Wenger has notably pioneered advancements in his years with Arsenal, as he told FourFourTwo.com: "Food is like kerosene. If you put the wrong one in your car, it's not as quick as it should be."

Matt Dunham/Associated Press

In summary, it seems nutritional science can be a secret weapon if coaches and teams are prepared to explore the possibilities. From Stromsgodset to Leicester City, the winning team will often be the most reactive, adaptable and willing to try new dietary protocols.

All quotes and information obtained firsthand unless otherwise indicated.