An athlete’s performance isn’t just about talent or years of training. It’s influenced by many factors, from mental resilience to physical endurance. Sometimes, one small detail can undermine months of preparation. That’s why behind every great athlete, there’s a team of professionals working to ensure they perform at their absolute best.

One of the most crucial factors? Nutrition. Over the years, sports nutrition has evolved tremendously. Today, every bite and sip an athlete takes (before, during, and after competition) is carefully planned down to the gram by sports nutritionists.

As I pursued my degree in dietetics, I became fascinated by the pivotal moments in sports history when the right food or drink gave athletes a competitive edge. In high-performance sports, even a 0.0001% difference can be game-changing.

Here are some of those moments I believe transformed how athletes prepare, compete, and recover.

Early breakthroughs (1900s-1960s)

1. The water ban and the 1904 Olympics

The 1904 St. Louis Olympics1 marathon is known as one of the most bizarre races in Olympic history. The race took place on August 30th, when the weather was hot and humid, and nearing almost 30°C at 2:30 PM when it began.

The length was 24.85 miles, shorter than today's standard of 26.2 miles. The route presented unique challenges: seven hills, poorly marked dirt roads, and a route design that forced runners to navigate around traffic and railroad tracks.

Thick dust choked the air, making breathing difficult for the 32 participants. One runner, the Californian William Garcia, was found unconscious with signs of internal bleeding.

Race organizers provided fresh water at only two points along the way —at the six and twelve-mile marks. This fluid intake restriction was because it was believed at that time that dehydration improved performance. The harsh conditions and limited hydration took a heavy toll: only 14 of the 32 runners completed the race.

This marathon also marked the first documented use of performance-enhancing substances in sports. The winner, Thomas Hicks, consumed multiple doses of strychnine (a rat poison that was used in small doses to stimulate the nervous system) mixed with egg whites and washed down with brandy. He won the race with the slowest recorded time of 3:28:53.

2. The carbohydrate loading revolution (1960s)

Sports nutrition science took a significant leap forward when Swedish researchers discovered how energy production in muscles worked by examining a small group of volunteers. Their study confirmed that the amount of glycogen stored in muscles directly correlated with endurance performance: the more glycogen (fuel in the tank), the longer an athlete could sustain physical activity.

This discovery led to the widespread practice of "carb loading". A method adopted by athletes and amateurs alike, including consuming large amounts of pasta or other carbohydrates the night before (or the meal before) a competition. While these pre-race pasta dinners were seen as essential for many years, modern nutrition science has revealed that optimal carbohydrate2 requirements vary significantly based on many other factors, including weight, exercise intensity, and duration.

Modern innovations (1970s-2000s)

1. Gatorade's birth at the University of Florida (1965)

Dr. Robert Cade and his research team revolutionized sports hydration when they developed the Gatorade Thirst Quencher for the Florida Gators football team. They aimed to create a beverage that would help football players maintain hydration and electrolyte balance during intense practices and games in hot conditions.

They took the carbs research from the Swedish and, knowing that they have a crucial performance-enhancing function during endurance exercise, they formulated a balanced carbohydrate-electrolyte beverage to replace the elements lost through sweating and exercise.

The University of Florida Gators football team, by drinking Gatorade, improved performance in hot weather and demonstrated the vital importance of electrolyte replacement during intense exercise, launching the sports drink industry.

2. Michael Jordan's pre-game ritual (1980s-90s)

When Michael Jordan joined the Chicago Bulls in 1984, he was one of the team's smallest players. Working with trainer Tim Grover in 1989, Jordan focused on building his biceps to intimidate opponents. As Grover noted in his book Winning: "What's the first thing you see on a basketball player when he takes off his warm-ups? Those arms. Details matter."

While his teammates embraced the carbohydrate-loading trend with pregame pasta meals, Jordan discovered this didn't work for his body—it left him feeling bloated. Instead, he developed his famous pre-game ritual: a steak consumed exactly three hours before tip-off, accompanied by a baked potato and water.

But besides the food itself, the meal was part of a meticulous routine that Michael Jordan would follow before each game. This personalized approach highlighted the importance of pre-game nutrition timing and helped establish standardized pre-competition meal protocols in professional sports.

3. Tour de France nutrition evolution (1980s)

The 1904 Olympic marathon's peculiar approach to hydration wasn't unique—early Tour de France nutrition3 was equally rudimentary. In fact, that year's winner, Henri Cornet, ate an unusual mix of hot chocolate (11 litres), tea (4 litres), champagne, and rice pudding (1.5 kilograms) daily.

With the birth of Gatorade and the carbohydrate-loading revolution, the 1980s marked a revolutionary shift toward scientific nutrition, including in professional cycling. The Tour's format of 21 stages, ridden over 23 days with only two rest days, demanded precise nutritional planning so cyclists had enough endurance to complete the tour.

Teams began calculating exact caloric needs for different stages, with riders consuming up to 8,000 calories daily during mountain stages. While specific strategies varied among teams, this decade established scientific nutrition as a cornerstone of professional cycling.

4. Precision hydration testing (2000s)

Taking Gatorade didn’t ensure that athletes were properly hydrated during their performance.

In the early 2000s, researchers came up with ideas to measure hydration in athletes. The development of sweat testing protocols transformed hydration strategies, with them nutritionists could better understand individual electrolyte needs.

This personalized approach replaced one-size-fits-all guidelines and sparked product diversification in the sports drink industry. Gatorade, which had focused solely on new flavours from 1965 to 1996, began developing specialized products like its Endurance Formula and low-calorie options.

Contemporary developments (2000s-Present)

1. Sports supplementation breakthrough (2000s)

In 2007, researchers at the University of Exeter, UK, demonstrated that dietary nitrate4 supplementation, particularly through sources like beetroot juice, could improve exercise performance.

Nitrate, a compound formed by Nitrogen and Oxygen, is found in food, mostly in leafy green veggies and drinking water. This component in the body is broken into simple parts and used to regulate blood flow, and therefore affects exercise performance. Supplementation with nitrate in the Exeter research showed a two to three percent improvement in endurance performance and enhanced oxygen utilization.

While two to three percent might not seem too much, for high-performance athletes, it can translate to a championship.

Another similar research led to the creation of the famous Jenkins Diet5. In 1981, Jenkins at the University of Toronto introduced the concept of the glycemic index (GI). This index ranked the foods containing carbohydrates based on their impact on blood glucose levels. The quicker a food raises blood sugar, the higher its ranking, with 100 being the maximum and corresponding to pure glucose. This work gave more understanding of what carbohydrates do in the body, including those related to the food intake periodization in sports nutrition.

Speaking of supplements, one that has popular use is Branched-Chain Amino Acids or BCAAs6, which were discovered in 1985 by the Swedish Public Health. Their study indicated that BCAA supplementation could reduce exercise-induced muscle damage, improve recovery times, and enhance endurance performance. This makes sense since BCAAs are a group of three essential amino acids that build muscle and cannot be produced in the body.

These milestones have significantly influenced modern sports nutrition practices, emphasizing the importance of carbohydrate quality, amino acid supplementation, and dietary nitrates in enhancing athletic performance.

2. Michael Phelps's Olympic diet (2008)

I remember watching the news about Michael Phelps during the 2008 Summer Olympic Games in Beijing. Phelps, already a triple world record breaker in the previous games (2004 Athens Games), was the swimming star in Beijing.

Aside from the news about his spectacular performance (he won eight gold medals and broke seven world records), his diet captured the media's attention. News7 focused the global attention on the diet of athletes, saying that they ate up to 12,000 calories per day. While the rumour stayed around until Rio 2016, Phelps clarified that these reports were exaggerated.

In fact, his diet was around 10,000 calories a day8. To put the number into perspective, a moderately active and average-sized adult man should eat 2,000 calories a day. Phelps ate five times this requirement, demonstrating the extreme nutritional demands of elite swimming.

I found out that for breakfast alone, he would eat: three fried-egg sandwiches with cheese, lettuce, tomatoes, fried onions, and mayonnaise; a five-egg omelet, a bowl of grits, three slices of French toast with powdered sugar, and three chocolate-chip pancakes. And two cups of coffee to wash it down.

Perhaps I was mostly astonished that he could eat a whole pizza along with pasta with carbonara sauce and energy drinks for dinner. The point is that the media coverage of his diet helped the public understand the massive caloric requirements of Olympic athletes and opened the discussion about sports nutrition.

The same Olympic games produced another memorable nutrition story. Jamaican star runner Usain Bolt revealed in his autobiography that he survived primarily on McDonald's chicken nuggets during the games. He consumed approximately 1,000 nuggets over ten days, to avoid unfamiliar Chinese cuisine that might not fit him right. Bolt set three world records and won three gold medals at that game.

These stories shed some light on elite athlete nutrition and highlight how some athletes adapt their diets to maintain familiar foods during high-pressure international competitions.

3. The rise of plant-based athletes (2010s)

Tennis is a sport I follow closely. I started playing it during that transition period between Agassi-Sampras and Nadal-Federer. The talk back then was about racquets and surfaces.

It was Nadal who sparked the conversation in the local clubs about the specific physical training needs for this sport. But two other tennis stars pioneered high-profile transitions to specialized diets, particularly challenging traditional beliefs about protein sources and athletic performance.

In 2010, Novak Djokovic9 became the center of attention for that. Being criticized for not finishing matches, he visited a doctor who, after a gluten and dairy sensitivity test, removed those elements from his diet. One year later, he had won three out of the four tennis Grand Slams.

On the women’s side, Venus Williams changed her diet to overcome an autoimmune disease10. The older of the Williams sisters began her career in a more promising light than Serena. But the disease forced her to take time off the courts and follow a raw vegan diet, which typically involves eliminating all animal products and foods cooked above 48°C.

4. Soccer's GPS-linked nutrition plans (2010s)

It was in the last few years that we started seeing GPS tracker vests11 on soccer players. Teams from England’s highest league of soccer, the Premier League, began using this technology to monitor players' movement patterns and energy expenditure during matches and training sessions.

While a GPS won’t tell nutritional data, it is the player’s overall performance data collected from it, alongside specific metabolic tests that help the team’s nutritionists estimate the player’s energy needs and optimize their fueling to each training session or match.

We can remember Messi12 throwing up on the pitch during matches in 2014 due to poor eating habits. At the end of the day, understanding each player's energy needs helps to create tailored nutrition strategies to support the performance and recovery of all soccer players.

The future of sports nutrition

The field continues to evolve to push the limits of human performance.

Today, the focus is on three areas: the usage of artificial intelligence for real-time nutrition plan adjustments and data integration; genetic nutrition profiling for nutrigenomics-based supplementation and individual recovery optimization; and for me, perhaps the most interesting area of development: the microbiome impact, for examining gut bacteria's influence on athletic performance and recovery.

From basic macronutrient understanding to today's highly personalized protocols, these milestones highlight the impact of nutrition on athletic achievement. We can expect nutrition to play an even more crucial role in the future of sports performance.

Notes

1 St Louis marathon: The strangest race in Olympic history at Olympics Official Website.
2 The Truth Behind Carb Loading at Ultiworld.
3 Timeline: A History of Tour de France Nutrition at Bicycling.
4 Dietary Nitrate Supplementation and Exercise Performance at the National Library of Medicine.
5 Glycemic index of foods: a physiological basis for carbohydrate exchange at the National Library of Medicine.
6 Dietary nitrate reduces muscle metabolic perturbation and improves exercise tolerance in hypoxia at the National Library of Medicine.
7 The Michael Phelps Diet: Don't Try It at Home on The Wall Street Journal.
8 Michael Phelps' 10000 calories diet: What the American swimmer ate while training for Beijing Olympics? at Olympics Official Website.
8 Novak Djokovic's life and career-changing gluten-free diet at Olympics Official Website.
10 What Venus Williams really eats—and how a drastic diet change impacted her life, career on SI.
11 How clubs use GPS to find top level on the Premier League website.
12 Lionel Messi reveals reason he kept throwing up on the pitch on TNT Sports.