Thursday, February 5, 2015

Health Benefits of Chocolate - Exercise & Athletic Benefits


Eating dark chocolate as a daily snack could help boost athletic performance

Dark chocolate has already been hailed for its positive effects on cardiovascular health -- and now a study undertaken at London's Kingston University has found the tasty treat could help give sports enthusiasts an extra edge in their fitness training.
A team led by postgraduate research student Rishikesh Kankesh Patel discovered that dark chocolate provides similar benefits to beetroot juice, now taken regularly by elite athletes after studies showed it can improve performance. "Beetroot juice is rich in nitrates, which are converted to nitric oxide in the body. This dilates blood vessels and reduces oxygen consumption -- allowing athletes to go further for longer," Mr Patel explained.

The team from the British university wanted to find out whether dark chocolate could provide a similar boost, as it contains a substance called epicatechin -- a type of flavanol found in the cacao bean, that also increases nitric oxide production in the body.

To test the theory, Mr Patel carried out a study with a group of nine amateur cyclists. The 23 year old researcher was supervised by sport science field leader Dr Owen Spendiff and senior lecturer in sport analysis James Brouner.

After undergoing initial fitness tests to establish a baseline for comparison, the participants were then split into two groups. The first group was asked to replace one of its normal daily snacks with 40g of a dark chocolate known to be rich in flavanols for a fortnight, while the other participants substituted 40g of white chocolate for one of their daily snacks as a control.

The effects of the athletes' daily chocolate consumption were then measured in a series of cycling exercise tests in the sports performance laboratory at the University's Penrhyn Road campus. The cyclists' heart rates and oxygen consumption levels were measured during moderate exercise and in time trials. After a seven-day interval, the groups then switched chocolate types and the two-week trial and subsequent exercise tests were repeated.

The study, which has now been published in the Journal of the International Society of Sports Nutrition, found that after eating dark chocolate, the riders used less oxygen when cycling at a moderate pace and also covered more distance in a two-minute flat-out time trial.

"We want to see whether the boost in performance is a short term effect -- you eat a bar and within a day it works -- or whether it takes slightly longer, which is what the initial research is showing," Mr Patel said. "We are also investigating the optimal level of flavanols. At the moment there is not a lot of consistency in flavanol levels in commercially-available chocolate. Once we've found the optimal chocolate dose and duration, we'll compare its effects to those of beetroot juice, and also test the influence of combining consumption of both, as they produce an increase in nitric oxide in slightly different ways."

Dr Owen Spendiff, who has conducted studies around beetroot juice and athletic performance, said that Mr Patel's work showcased some of the cutting-edge research being carried out within Kingston University's sport science facilities. "Rishikesh's findings are really interesting, as he has proven the exercise benefits of dark chocolate for the first time," he said. "The fact he began his research into dark chocolate as an undergraduate and is now carrying that forward at postgraduate level here really demonstrates what our sport science students can achieve."

Meanwhile sport analysis lecturer James Brouner -- who in his spare time pounds the pavements as an ultra-distance runner -- said that the research suggested dark chocolate could offer particular benefits to endurance athletes.

"From a performance perspective, making an athlete more efficient can have major advantages in long duration steady-state exercise," he said. "With so many athletes consuming beetroot juice to achieve this gain but complaining of the palatability, dark chocolate could have a similar effect but with the additional benefit of tasting good too. "When performing endurance-based activity, being as economical as possible in energy provision is key to enhancing your performance. From our results, the consumption of dark chocolate has altered the participants' response to the activity and therefore could enhance their endurance performance."

Drinking chocolate milk after a workout offers advantages for post-exercise performance and muscle repair

One of the best post-exercise recovery drinks could already be in your refrigerator, according to new research presented at the American College of Sports Medicine 2010 conference. In a series of four studies, researchers found that chocolate milk offered a recovery advantage to help repair and rebuild muscles, compared to specially designed carbohydrate sports drinks.

Experts agree that the two-hour window after exercise is an important, yet often neglected, part of a fitness routine. After strenuous exercise, this post-workout recovery period is critical for active people at all fitness levels – to help make the most of a workout and stay in top shape for the next workout.

The new research suggests that drinking fat free chocolate milk after exercise can help the body retain, replenish and rebuild muscle to help your body recover. Drinking lowfat chocolate milk after a strenuous workout could even help prep muscles to perform better in a subsequent bout of exercise. Specifically, the researchers found a chocolate milk advantage for:

• Building Muscle – Post-exercise muscle biopsies in eight moderately trained male runners showed that after drinking 16 ounces of fat free chocolate milk, the runners had enhanced skeletal muscle protein synthesis – a sign that muscles were better able to repair and rebuild – compared to when they drank a carbohydrate only sports beverage with the same amount of calories. The researchers suggest that "athletes can consider fat-free chocolate milk as an economic nutritional alternative to other sports nutrition beverages to support post-endurance exercise skeletal muscle repair."

• Replenishing Muscle "Fuel" – Replacing muscle fuel (glycogen) after exercise is essential to an athlete's future performance and muscle recovery. Researchers found that drinking 16 ounces of fat free chocolate milk with its mix of carbohydrates and protein (compared to a carbohydrate-only sports drink with the same amount of calories) led to greater concentration of glycogen in muscles at 30 and 60 minutes post exercise.

• Maintaining Lean Muscle – Athletes risk muscle breakdown following exercise when the body's demands are at their peak. Researchers found that drinking fat free chocolate milk after exercise helped decrease markers of muscle breakdown compared to drinking a carbohydrate sports drink.

• Subsequent Exercise Performance – Ten trained men and women cyclists rode for an hour and a half, followed by 10 minutes of intervals. They rested for four hours and were provided with one of three drinks immediately and two hours into recovery: lowfat chocolate milk, a carbohydrate drink with the same amount of calories or a control drink. When the cyclists then performed a subsequent 40 kilometer ride, their trial time was significantly shorter after drinking the chocolate milk compared to the carbohydrate drink and the control drink.4

Why Chocolate Milk?

Chocolate milk's combination of carbohydrates and high-quality protein first made researchers take notice of a potential exercise benefit. The combination of carbs and protein already in chocolate milk matched the ratio found to be most beneficial for recovery. In fact, studies suggest that chocolate milk has the right mix of carbs and protein to help refuel exhausted muscles, and the protein in milk helps build lean muscle. This new research adds to a growing body of evidence suggesting milk can be just as effective as some commercial sports drinks in helping athletes refuel and recover.

Milk also provides fluids for rehydration and electrolytes, including potassium, calcium and magnesium lost in sweat, that both recreational exercisers and elite athletes need to replace after strenuous activity. Plus, chocolate milk is naturally nutrient-rich with the advantage of additional nutrients not found in most traditional sports drinks. Penny-for-penny, no other post-exercise drink contains the full range of vitamins and minerals found in chocolate milk.


First-of-its-kind study: Swimmers gain an advantage when they recover with chocolate milk

Swim times are significantly faster when swimmers recover with chocolate milk, compared to a typical sports drink or a calorie-free beverage

Grabbing chocolate milk after a hard swim could give swimmers a performance edge, according to new research presented at one of the nation's top sports medicine conferences – the American College of Sports Medicine's annual conference.1 In a sport where seconds and even tenths of a second can make a big difference and intense practice routines are the norm, Indiana University researchers found that when collegiate, trained swimmers recovered with chocolate milk after an exhaustive swim, they swam faster in time trials later that same day. On average, they shaved off 2.1 seconds per 200 yard swim, and 0.5 seconds per 75 yard sprint, compared to when they recovered with a traditional carbohydrate sports drink or calorie-free beverage.

"Chocolate milk is an ideal recovery drink. It's a 'real food,' has the right carb to protein ratio athletes need and it's less expensive than many alternatives," said Joel Stager, PhD, lead researcher at Indiana University. "From cyclists to runners to soccer players, there's a strong body of research supporting the benefits of recovering with chocolate milk. Now, our research suggests these same benefits extend to swimmers – a sport that relies on quick recovery for multiple races within a single day."

The study is the first to test the benefits of chocolate milk in swimmers, and included six division one collegiate swimmers performing a muscle fuel (glycogen) depleting swim bout of 60 x 100 yards followed by five hours of recovery for three consecutive weeks. The athletes then recovered with one of three randomized beverages – reduced fat chocolate milk, commercial carbohydrate sports drink (with the same calories as the chocolate milk), or calorie-free beverage – immediately and two hours after the swim. Following the five-hour recovery period, three swim performance test sets were completed relying on aerobic (200 yards), anaerobic (75 yard sprint), and immediate energy metabolism (10 meters against resistance). While there were no differences in the immediate energy metabolism swims, there were significant differences in the aerobic and anaerobic swims – indicating better recovery after drinking chocolate milk.

Researchers, including Dr. Stager,2 first studied chocolate milk because of its unique carb to protein ratio and now more than 20 studies support the benefits of recovering with the high-quality protein and nutrients in chocolate milk after a tough workout.3 With high-quality protein to build lean muscle, the right mix of protein and carbs to refuel exhausted muscles, and fluids and electrolytes to help replenish the body, chocolate milk is a trusted part of many athletes recovery routines.

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SOURCES

1. Stager JM, Brammer CL, Sossong T, Kojima K, Spanbaur D, Grand K, Wright BV. Supplemental recovery nutrition affects swim performance following glycogen depleting exercise. Presented at the American College of Sports Medicine, 2014.

2. Karp JR1, Johnston JD, Tecklenburg S, Mickleborough TD, Fly AD, Stager JM. Chocolate milk as a post-exercise recovery aid. Int J Sport Nutr Exerc Metab. 2006;16:78-91.

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