Consumption of a Carbohydrate Performance Drink Increase

¶ … 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.

Literature Review

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.

Gender Differences

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 capacity. It was further found that fat, but not carbohydrates were important in preventing a drop in blood glucose concentration during fasting exercise (Van Proeyen, Scluficik, & Nielens, 2011b).

Ramadan is a Muslim holiday that involves partial fasting for a long period of time. In a study that examined Muslim men in this fasted state, it was found that subjects in a fed state were able to outperform those in a fasted state in a 1 hour endurance run (Aziz, Wahid, & Prig, 2010). Differences in individuals varied but the differences were significant. The studies demonstrate the effects of fasting on its ability to decrease endurance. High fat diets were found to be more effective in preventing muscle degradation than high carbohydrate diets. The studies will have an impact on the proposed study design, in terms of controlling dietary variables that can affect the outcome.

In a placebo controlled study, athletes were divided into two groups, one of which ingested an amphetamine (methylphenidate) prior to exercise performance. Subjects who took the amphetamine were able to cycle 32% longer before their output fell to 70% of the starting value. Those receiving the amphetamine had significantly higher oxygen consumption, heart rate, and blood lactate concentrations. Amphetamines resulted in cyclers who could exercise longer. Muscle fatigue was the main factor that caused the athletes to discontinue exercising, regardless of the group they were in (Swart, Lamberts, Lambert, 2009b). This research demonstrates the ability of drugs to influence the outcome of research studies involving carb-loading.

Training Regimes and theories differ significantly in the literature. In a study that examined training daily and training twice every second day, the ability to engage in high-intensity training was compromised in the every second day training schedule. However, there was little change in time trials using either training method (Yeo, Paton, & Garnham, 2008). This is only one of many studies that examines the effect of training schedules and methods on performance. In terms of the proposed research study, it highlights the importance of selecting a consistent training schedule for all participants.

Perceived exertion perceptions also affect performance. During maximum effort time trials, feedback was withheld until the final kilometer. This study found that when athletes are certain about the endpoint of the exercise, they are more aggressive and achieve higher performance. They are able to apply strategies that help them to improve performance. Uncertainty about the endpoint of the exercise decreases performance and increases perceived exertion (Swart, Lamberts, & Lambert, 2009).

Conclusion

Carbohydrate loading has been an accepted strategy to enhance athletic performance for several decades. However, as research progresses and we know more about the mechanism responsible for its affects, the more uncertain we become about its ability to enhance performance in any individual. A majority of the studies found in the literature were conducted using male subjects. Very few studies were found that involved female subjects. Those that were found indicated that several factors unique to the female body caused carbohydrate loading to have different effects on female athletes than on males. More research needs to be conducted on the effects of carbohydrate loading on females, specifically on the effects of hormones and the menstrual cycle on performance. This research will add to the information available on the performance of female athletes and their response to performance drinks before a short, intense sprint.

Carbohydrate loading takes place several days prior to the athletic event. Sports drinks claim to enhance performance by providing a short burst of energy immediately prior to an event. The literature indicated that carbohydrate loading is only effective for physical activities that continue for 30 minutes are more. Yet, sports drinks claim that their drinks can enhance performance, without being specific as to the duration of the effects. This research will examine the effects of a specific brand of energy drink on short-term, intense performance in female athletes.

One of the characteristics that stood out in a majority of the literature was the inability to control confounding variables. The literature review found several factors that could affect the outcome of the proposed study and ones that were similar to it. Among these factors were fasting, the consumption of a high fat diet, drug consumption, the perceived intensity of the activity, and whether the athletes could see the endpoint, and training schedules. All of these factors represent confounding variables and many of the studies found failed to account for these and other factor that could affect the results. This makes it difficult to attribute the condition under study to the effects that were found in the study. Controlling confounding variables creates uncertainty the reliability of the results of many of the studies that were found during the literature review. The proposed study will take into account the confounding variables that were identified during this literature review and any others that are found during the course of the proposed research study.

The most apparent finding of this literature review was that the more we discover about how to enhance athletic performance, the more we know is yet to be discovered. Individual performance can be affected by a number of factors. Many of these factors can be eliminated as a causal condition in this study design. Isolating the dependent variable will prove to be the most challenging aspect of the study. It is important to ensure equal treatment of the female participants to the greatest extent possible during the course this study. The presence of confounding variables discovered through the literature review will represent a key challenge in the research design.

The literature review focused on the effect of long-term carb-loading on endurance events. It appears that once studies began to suggest that carb-loading was only effective for endurance events, studies regarding carb-loading for short-term, high-intensity events were all but abandoned by the academic community. Now, the market is flooded with sports drinks that claim to be a panacea for increasing performance in all sports events categories. At present, the literature simply does not contain enough evidence to support these claims. Sports drink claims are based on carb-loading theory, via consumption of their drink just prior to performance of a sports event. These claims are simply not supported by a majority of the literature that exists. Literature was found to the contrary, which claimed that carb-loading was not effective when short burst speed was needed. This study will provide insight as to whether carb-loading just prior to a short-term, high-intensity event will improve performance, or whether previous literature will be supported and it will have no effect.

Rationale

A literature review revealed that there are many gaps in research concerning athletic performance in the factors that affect it. This research will fill one small gap in sports nutrition and medicine. The aim of this study will not be to support or dispute claims by a manufacturer, but rather to examine the effects of sport drinks as a whole. However, the use of a single sports drink will serve the purpose of eliminating a confounding variable from the study due to variability in sports drink content. This study will fill the gap in the literature concerning the effectiveness of sports drinks consumed 2 hours before an athletic event.

This study method chosen will be similar to other studies found during the literature review. The study design will address design issues that were found in the other studies, such as the presence of conditions that could interfere with the results. One of the most difficult aspects of the study will be to eliminate the presence of placebo affect from the study groups. The placebo affect is a common difficulty to overcome in many clinical studies. This issue is difficult to resolve in a single study and often requires repeat performances of the study to eliminate the possibility that placebo effect was responsible for the results obtained.

The study procedure involves selection of 20 female athletes between the ages of 18 and 22. The participants will be selected from a group of volunteers from a local university. All of the volunteers will be involved in some type of track and field sport. The 400m sprint is the longest of the competitive sprints. It requires greater endurance and stamina to maintain maximum effort for the entire distance. The athletes will be divided into two groups. Both of the groups will perform the 400m sprint for five trials and their scores will be recorded.