consumption of a carbohydrate performance drink increase 400m sprint times?
Carbohydrate loading was found to be beneficial for endurance sports in the late 1990s. Research has demonstrated that consuming high amounts of carbohydrates, combined with low training levels for several days before an event can help to improve performance (Wade, 2008). Since that time, issues have arisen as to which types of carbohydrates are best, which proteins are a factor, and issues regarding gender and differences in metabolism. Results of studies differ in regards to these issues.
The idea that carbohydrate-loading before an endurance event is widely accepted among health and fitness professionals. Now, the food industry has seen the profitability potential in this increased hype about carbohydrate-loading. They have crowded supermarket shelves with performance drinks, performance bars, and powders that can be added to other foods, supposedly to increase performance in sports activities. This research will focus on one particular type of performance drink and will conduct a series of tests to see if using it as directed increases performance in the 400m sprint for women.
The topic of carb-loading and athletic performance has been of interest for several decades. Results of clinical studies generally agree that carb-loading can improve performance in many athletes. However, a number of studies also indicate that this is not always the case. Disagreements exist in the literature as to when and how carbohydrate loading is effective. A literature review was conducted that explored clinical evidence on the topic of carbohydrate loading as well as important studies in the history of the topic. The literature review also explored several topics that were specific to the topic of this research study.
The Basics of Carb Loading
Long before studies on carbohydrate-loading, protein consumption, and energy expenditure during sports was studied by the medical community, the connection between sports performance and nutrition was accepted. Clinical evidence in the area began to mount and the knowledge became more specific. Carbohydrate-loading is a nutritional strategy designed to help store energy in the muscles before an athletic event. Any physical activity requires carbohydrates for fuel. Endurance sports require extra energy so that the athlete does not expend all of their energy and become fatigued. Marathon runners, swimmers, and cyclists who are doing an event that will last 90 minutes are more are considered to benefit from carbohydrate-loading (Mayo Clinic, 2006).
Carbohydrates are the energy that provides the fuel for muscles to contract. Carbohydrates break down into simple sugars, largely glucose, fructose, and galactose. The simple sugars are absorbed in used as energy. If consume more than our body needs at one time it gets stored in the kidneys as glycogen. Once all of the glycogen stores have filled to capacity, the rest is stored as fat. Glycogen stores are used for short, intense exercise such as sprinting adn weight lifting. Glycogen is immediately accessible and is the source of energy for the first few minutes of any exercise. During longer term sports activities glycogen is necessary to help pull fat from the body and turn it into energy (Mayo Clinic, 2006).
The third source of energy is proteins. If the body runs out of carbohydrates and fat, then it begins turning protein into glucose for energy. Proteins are the primary building blocks for the body. They help us to build muscles, bones, skin, hair, and other important body parts. If one exhausts our carbohydrate sources for energy, then the body does not have enough protein to maintain the tissues and they begin to break down. Protein breakdown also creates many by products that do not break down easily, creating kidney stress (Mayo Clinic, 2006).
It is generally accepted that the body begins using glycogen stores after 30 minutes of exercise in that it can continue to use them for up to 90 minutes (DFJDLKJ). Carbohydrates are divided into simple and complex forms. Simple sugars are quickly absorbed and converted to energy. They are the fastest source of energy. Complex carbohydrates take longer to enter the body as they must be digested and broken down first. They provide energy at a slower rate than simple sugars. Foods that contain high amounts of starch and fiber are considered complex carbohydrates, but fiber is not used for energy. Starch is easily broken down and stored as glycogens.
When athletes talk about carb-loading, what they are referring to is storing up carbohydrates using complex carbohydrates such as breads, rice, pasta, cereals, and other grains. Sports drinks and fruits count as simple carbohydrates and are not included in the carb-loading diet of athletes. These are quick energy and are considered the first be burned.
In a clinical study, a high carbohydrate diet was found to have different effects in athletes with differing levels of aerobic capacity. Athletes were divided into several groups. One group trained with carbohydrate-loading, one group trained without carbohydrate-loading, a third group involved untrained athletes with carbohydrate-loading, and the last group was untrained athletes without carbohydrate-loading. Confectionery products were used as a means to supplement normal carbohydrate intake in these trials. The study concluded that this was an effective means for loading carbohydrates to improve performance. It was found that athletes with a lower level of aerobic capacity responded more to carbohydrate-loading than those that had higher levels of aerobic capacity (Sulio, Monda, & Brizzi et al., 1998).
Burke, L., Hawley, J., & Schabort, E. et al. (2000), found that carbohydrate-loading did not improve performance during 100 km cycling events. These authors surmise that perceived benefits of carbohydrate-loading were due to the placebo effect. Carbohydrate-loading did significantly increase muscle glycogen concentrations, but did not result in measurable performance enhancements during the activity.
Carbohydrate-loading usually entails an intense training to deplete glycogen for two days. This is followed by a glycogen loading of 3 to 14 days which comprises ingesting 60 to 70% of the total energy intake as carbohydrates. However, more recently the glycogen depletion has been eliminated in many programs. In a recent study, it was found that glycogen loading does not have the same affect on males and females. Therefore, the effects of carbohydrate-loading on performance differ as well (Wisman & Willoughby, 2006). Not only does carbohydrate loading effect female athletes differently performance wise, it also affects them in the recovery stage as well. Female athletes had different reactions in terms of metabolic, thermoregulatory, inflammation and the repair processes (Hausswirth & LeMeur, 2011).
Ovarian hormones and the stage in the menstrual cycle were found to be causal in some of the effects found in female athletes. Female athletes tend to demonstrate less capacity to restore normal body temperature after an athletic event than males. They must often take extra measures to return to normal body temperature such as ice water or fans (Hausswirth & LeMeur, 2011). The studies indicate that training and recovery methods should be different for males and females based on physiological reaction during and after athletic activity.
Carbohydrate-loading in men can increase their glycogen levels from between 25 and 100% of the norm (Hausswirth & LeMeur, 2011). In women, carbohydrate-loading may not be as effective. Few studies have examined carbohydrate-loading in women and those that have demonstrated mixed results. It is suspected that women need a higher calorie intake during carbohydrate loading to see the same benefits as men. A woman's menstrual cycle may also have an effect on the efficiency of carbohydrate-loading and glycogen stores. Certain health conditions such as diabetes can also affect the ability to store glycogen during the carbon loading process (Hausswirth & LeMeur, 2011).
Variables that Affect the Efficacy of Carbohydrate Loading on Performance
The proposed study will explore the effectiveness of sports drinks taken by women 2 hours before short duration, intense sporting events. Many women are concerned about losing weight and often fast or engage in low calorie diets. Therefore, it is relevant to explore the affects of fasting on performance after carbohydrate loading. Several studies have also indicated of fat loading can play a role in the effectiveness of carbohydrate loading.
A high fat diet followed by one day of carbohydrate loading was found to increase fat oxidation during a 100 km cycling time trial. However, it compromised high-intensity sprint performance. Researchers suspected that this was possibly due to increased sympathetic activation or altered contractile function (Havermann, West & Goedecke, 2006).
In another stud, the effects of fasting on endurance training vs. consumption of a high fat diet during endurance training were compared. It was found that a high fat, high calorie diet contains sufficient carbohydrates to maintain sufficient glycogen in the muscle during training. It was found that this diet did not impair muscle glycogen breakdown due to exercise (Van Proeyen, Szlufcik, & Nielens, 2011a). The same authors also conducted a study that explored limited carbohydrate availability and training. It was found that consistently training in a fasted state has an effect on muscle metabolism. Fat was found to be more effective than carbohydrates in its ability to increase muscular oxidative…