Sports nutrition

Sports nutrition is the study and practice of nutrition and diet as it relates to athletic performance. Although an important part of many sports training regimens, it is most commonly considered in strength sports (for example weight lifting and bodybuilding) and endurance sports (for example cycling, running, and triathlon). Sports nutrition is a science that produces or provides and maintains the food (or dietary ergogenic aids) necessary for health, growth and physical performance. It deals with nutrients such as vitamins, minerals, supplements and organic substances such as carbohydrates, proteins and sugars in serious athletes of all sorts who want to make use of nutrition for their benefit. An athlete's dietary regimen plays a vital part in accomplishing his/her goals because it allows the athlete to reach his/her maximum performance. This illustrates how an athlete should apply the necessary nutrition in order to benefit from training and to maximize his/her capability during exercise and activity. Thus, every sport and type of physical activity varies in its appropriate diet which benefits the athlete. Sports nutrition also consists of many different concerns such as the amount of certain foods and fluids one should consume that are specific to training. The goals of sports nutrition try to answer the questions such as: What types of foods and fluids should be consumed? What to eat and drink and when throughout the day?

History of Sports Nutrition

Since the beginning of mankind, the idea of diet and exercise has always been in place. From the time when the ancient Greeks and Romans started the Olympic games, the athletes had their own special regimen for great performance. For example, Milo of Croton, the wrestler with legendary strength who won five successive Olympic Games from 532 to 516 B.C., ate “9 kg (20 pounds) of meat, 9 kg (20 pounds) of bread and 8.5 L (18 pints) of wine a day,” according to Athenaeus and Pausanius (Grandjean). Alcohol was commonly drunk as an ergogenic aid to increase performance in the Olympics through the early 1900s. However, the view of sports nutrition today has much evolved from the ancient Olympic gladiators’ meal plan. Scientists are continually interested in learning more about this abiding subject. Research shows that the coupling of exercise and proper diet is what produces a healthy lifestyle that can maintain the “prevention/management of [chronic diseases such as] noninsulin-independent diabetes, hypertension, coronary heart disease, osteoporosis, obesity, mental health, colon cancers, stroke and back injury.” In 2008, US News reported that 65% of Americans exercised regularly by working out, playing sports, and/or other physical activities, thus the importance of proper nutrition is of great interest to athletes and exercisers for optimal performance and long term benefits. In addition to diet, social and cultural influences, lifestyle habits, motivation and training determine successful athletic performance (Maughan). However, states Maughan, “without proper nutrition, the full potential of the athlete will not be realized, because performance will not be at its peak, training levels may not be sustained, recovery from injury will be slower, and the athlete may become more susceptible to injury and infection.” Understanding sports nutrition leads to optimal athletic performance and lifetime health benefits and can thus be evaluated by the intake of certain nutrients and supplements when exercising, by learning the way the body utilizes these materials and how these practices complement future diet and exercise of the individual. Look below under "External Links" for a history of sports nutrition timeline.

Goals of Sports Nutrition

Sports nutrition has many goals to enhance performance. First, it improves performance by improving body composition, which increases speed, quickness, mobility, and strength. Second, it will help the speed of recovery, which will in turn create more capacity for practicing and competition as the body is becoming more fit and adjusted to the coupling of the good nutrition incorporated into the workout regimen. Third, it will allow one to increase energy for both practice and competition, which will definitely help one's performance. Strategic diet will also increase immunity, allowing one to stay healthy and be able to continue and intensify practice and training. Most importantly, it will improve your overall health as proper health is essential to all aspects of life.

Supplements

Many athletes consider taking dietary supplements because they are looking for the “magic ingredient” to increase performance. In the extreme case of performance-enhancing supplements, athletes (particularly body-builders) may choose to use illegal substances such as anabolic steroids, compounds which are related to the hormone testosterone, which can quickly build mass and strength, but have many adverse effects such as high blood pressure and negative gender specific effects. Blood doping, another illegal ergogenic, was discovered in the 1940s when it was used by World War II pilots.

Dietary protein began to be consumed in the 1940s and muscle building results were found in resistance and strength training athletes. Protein intake is a part of the nutrient requirements for the regular athlete and is an important component of exercise training, because it can also aid in performance and recovery. Dietary protein intake for well-trained athletes should occur before, during and after physical activity as it is advantageous in gaining muscle mass and strength. However, if too much protein and amino acid supplements are consumed (especially by the Average Joe exerciser), it can be more harmful than beneficial; health risks include: “dehydration, gout, calcium loss, liver, and renal damage [and] gastrointestinal side effects include diarrhea, bloating, and water loss" (Lawerence). A bountiful protein diet must be paired with a healthy, well-rounded meal plan and regular resistance exercise. Yet, characteristics such as the type of exercise, intensity, duration, the carbohydrate values of diet, the individual's sex and age and also the amount of background training and training environment.

Creatine may be helpful for well-trained athletes to increase exercise performance and strength in concordance with their dietary regimen. Also, the substance glutamine, found in whey protein supplements, is the most abundant free amino acid found in the human body. For well-trained and well-nourished athletes it is considered that glutamine may have a possible role in stimulated anabolic processes such muscle gylocgen and protein synthesis. Other popular supplements studies done include androstenedione, chromium, and ephedra. The findings show that there are no substantial benefits from the extra intake of these supplements, yet higher health risks and costs.

High energy supplements have shown to increase the performance of physical activity. A study done at the University of Texas saw a 4.7% increase of performance in 83% of participants after drinking Red Bull Energy Drink which was more intense than the compared placebo. The energy drink most dominantly increased the epinephrine and noreprinephrine (adrenaline and its precursor) levels and beta-endorphins in the blood than before consumption. Caffeine, carbohydrates and Vitamin B are factors that may have favored performance increase with no change in perceived exertion.

Caffeine has been known since the 1900s and became popularly used since the 1970s when its power of masking fatigue became highly recognized. Similarly, the caffeine found in energy drinks such as Redline Extreme shows an increased reaction performance and increased good feelings of energy, focus and alterness in quickness and reaction anaerobic power tests. In other words, consuming an energy drink with caffeine increases short time/rapid exercise performance (like short full-speed sprints and heavy power weight lifting.)

Post-Exercise Nutrition

Post-exercise nutrition is just as important, if not more important than pre-exercise nutrition as it pertains to recovery. Traditionally, sports drinks such as Gatorade and Powerade, are consumed during and after exercise because they effectively rehydrate the body by refueling the body with minerals and electrolytes. Gatorade was founded in the 1960s, when the University of Florida, Gainesville Gators improved their performance with “Gator Aid.” A drink was made of glucose and sucrose in water and helped the football players' performance. And by the 1970s, many other sports drinks of its kind had been manufactured. However, sports drinks lack protein.

New studies in 2008 have found milk, especially skim milk and chocolate milk may be the new sports drink, as milk leads to protein the synthesis which boosts net muscle protein balance. Milk naturally contains many electrolytes, nutrients and other properties that help to make it a great post-exercise beverage to commercial sports drinks. Lean mass has been observed when an individual has had at least 12 weeks of resistance training. With post-exercise milk as an efficient rehydration beverage, it increases muscle hypertrophy, has acute alterations in protein synthesis and replaces nutrients than traditional sports drinks. In post-exercise nourishment, athletes like body builders may find milk more beneficial for gaining muscle mass, yet both traditional sports drinks and milk are found to be sufficient and adequate for the majority of exercisers for replenishment.

Nutrition for Anaerobic Exercise

During anaerobic exercise, the process of glycolysis breaks down the sugars from carbohydrates for energy without the use of oxygen. This type of exercise occurs in physical activity such as power sprints, strength resistances and quick explosive movement where the muscles are being used for power and speed, with short time energy use. After this type of exercise, there is a need to refill glycogen storages in the body (the long simple sugar chains in the body that store energy), although they are not likely fully depleted.

To compensate for this glycogen reduction, athletes will often take in a large amount of carbohydrates in the period immediately following exercise. Typically, high glycemic index carbohydrates are preferred for their ability to rapidly raise blood glucose levels. For the purpose of protein synthesis, protein or individual amino acids are ingested as well.

Often times in the continuation of this anaerobic exercise, the product from this metabolic mechanism builds up in what is called lactic acid fermentation. Lactate is produced more quickly than it is being removed and it serves to regenerate NAD⁺ to the cells where it's needed. During intense exercise when oxygen is not being used, a high amount of ATP is produced and pH levels fall causing acidosis or more specifically lactic acidosis. Lactic acid build up can be prevented treated by staying well-hydrated throughout and especially after the workout, having good cool down routine and good post-workout stretching.

Nutrition for Aerobic Exercise

In aerobic exercise, oxygen is needed to supply energy and this oxidation helps neutralizes free radicals. After aerobic exercise, it is necessary to refill the glycogen stores in the skeletal muscles and liver. There is a 30 minute window after exercise critical to muscle recovery. Before doing anything else, drink something for recovery. Liquids are ideal (like water, juice or sports drinks) and as mentioned above, low-fat milk and chocolate milk are effective recovery beverages because of their ideal 4:1 combination of carbohydrate and protein that fuels and replenishes muscles the best.

Metabolism is slow so that the body can work through endurance exercises such as long distance running or swimming because these activies require constant use of oxygen to supply energy. Fats (lipids), carbohydrates (sugars), proteins and other substrates are different substances the body can utilize to make sufficient ATP energy. In addition, men and women have different ways of metabolizing these substrates. It has been found that women oxidize more lipids (fat-burning), less carbohydrates, and less amino acids than do men during endurance exercise. These differences may be linked to the higher levels of female sex hormones 17-beta-estradiol, estrogen and progesterone. In addition, women should carbohydrate-load by consuming more than about 8g of carbohydrates per kg per day to overcompensate for lower habitual energy intake consumed during long aerobic activity for optimal performance.

Also, gender may lead to differences in the "Fight or flight" hormone epinephrine (commonly known as adrenaline). During exercise, men have higher sympathetic (sympathetic nervous system) activity during exercise, stimulating epinephrine and norepinephrine, making the concentrations higher in the blood. Adrenaline is a natural vasodilator, (which allows oxygen to flow faster and reach the muscles faster through blood vessels (especially arteries)), it increases heart rate, dialates the pupils and constricts arterioles in the skin and gastrointestinal tract. The sex hormones may be the link to the gender differences in metabolism, causing women to need carbohydrates (sugars) for endurance and for men to gain more epinephrine during exercise.