The Effects of Caffeine

Abstract

Caffeine is a widely used substance in the day to day diets of most athletes, with daily consumption reported to be between 70-76 mg per person worldwide. The aim of this study is to find out what effect caffeine will have on performance, during a 1 km cycle. The experiment took place at the Hermitage Academy, Chester le Street; on the 28th October 2012, at 11:15 a.m. The group of 12 participants who took part in the study were randomly selected from a variation of players from Durham County Presidents American Football team. The participants in the caffeine intake group (Y) were asked to ingest 6mg - kgˉ5 body mass of caffeine in the form of Pro-Plus and the other group were given a placebo. The caffeine group (Y) showed a mean performance time of 78.74 ± 5.93 (s) and the placebo group (N) showed mean time of 81.39 ± 4.46 (s). However, there was no significant difference that would recommend for regular use of caffeine, as a performance enhancing drug, during a competitive event.

Introduction/Literature Review

Caffeine is a widely used substance in the day to day diets of most athletes, with daily consumption reported to be between 70-76 mg per person worldwide (Gilbert, 1981). Caffeine's metabolic and performance effects have been extensively reported. However caffeine's effect on sustained intensive exercise are unknown (Backhouse et al., 2011). According to research data, the effects of caffeine on exercise performance, relative to an improved speed continue to be indistinct (Graham, Hibbert, and Sathasivam, 1998; Nehlig, Daval, and Derby, 1992). The ergogenic prospective of caffeine on endurance performance tasks lasting up to 1 hour have been well

documented and concise in numerous reviews (Burke, 2008; Doherty and Smith, 2004; Ganio et al., 2009). The ergogenic potential of caffeine during prolonged exercise is inevitable; the following statement backs up this theory. "Most investigations have examined exercise endurance in situations where fatigue occurs in 30 to 60 minutes. There can be no doubt that caffeine is ergogenic in these situations" (Graham, 2001, p.795). In a study, of the effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1 km cycling time trial, carried out at the Canterbury Christ Church University, eight trained male cyclists with a mean age of 32 ± 6 years and an average body mass of 73.6 ± 6.2 kg were asked to participate in the experiment, caffeine derived from dissolved Pro-plus tablets were used during the experiment. The dose contained 5 mg - kgˉ1 of dissolved caffeine combined with 200 ml of lemon concentrate and 50 ml of water. This mixture used in previous experiments, resulted in an improvement in performance time whilst waning the side effects associated with caffeine intake (Pasman et al., 1995). The placebo contained 200ml of lemon concentrate and 50ml of water. Both were prepared separately and placed in identical clear bottles, labelled 'A' (Caffeine) and 'B' (Placebo). The athletes were then pre tested following a protocol set out by the researchers, and the results were recorded. All treatments were administered using a double-blind fashion, this was used so neither the researchers nor the participants could manipulate the results in their favour. The participants then consume all of their solution and were asked to rest for 1 hour. After the rest the participants were asked to complete the 1 km cycle with maximal effort. The results show that there was an increase in performance time for those who ingested the caffeine solution 71.1 ± 2.0 s and those who ingested the placebo showed results of 73.4 ± 2.3 s. (Wiles et al.,

2006). The results of this test show that there is an improved performance time when caffeine is ingested. In comparison; a study carried out by researchers at the University of Western Australia, looked into the effects of caffeine on time trial performance in sedentary men, this experiment involved 12 sedentary men who were non-regular caffeine users; the participants mean age was 25 ± 2.2 years, with a mean body mass of 76.2 ± 12.2 kg. The participants were asked to attend 3 separate sessions, a practice session and two experimental sessions. During the experimental sessions (one week apart) the participants were asked to not exercise and not to ingest any caffeine products, other than the capsules given (caffeine and placebo) over the space of 48 hours and to fast 12 hours prior to the experiment; participants and researchers followed a double-blind fashion. 1 hour prior to the experiment the participants were asked to ingest either 6mg - kgˉ1 body mass of caffeine (No-Doz Awakeners) or the equivalent in placebo (Sugarino) both contained in opaque gelatine capsules. Participants completed a 1 km cycle at their own pace, and results showed that the participants who ingested caffeine completed the test within 120.4 ± 8.6 seconds and the placebo group completed the test within an average of 124.2 ± 5.1 seconds. The aim of this study is to find out what effect caffeine will have on performance, during a 1 km cycle.

1.0 Hypothesis

The ingestion of caffeine shows a significant improvement in performance time, between those that intake caffeine and those that do not.

1.1 Null Hypothesis

The ingestion of caffeine shows there is no significant improvement in performance time, between those that intake caffeine and those that do not.

2.0 Method

2.1 Groups

The group of 12 participants were randomly selected from a variation of players from Durham County Presidents American Football team, with an average in height of 177.9 ± 5.0 (cm), an average weight of 80.4 ± 11.7 (kg) and an average age of 25.5 ± 5.1 (years of age) The participants were divided into a caffeine intake group (Y) and placebo intake group (N). Full consent was given from all participants, in the form of a Physical Activity Readiness Questionnaire (PAR-Q).

2.2 Testing Protocol

The participants in the caffeine intake group (Y) were asked to ingest 6mg - kgˉ5 body mass of caffeine in the form of Pro-Plus (Bayer, UK) dissolved with 50 ml water. The placebo group were asked to consume the same solution - without the dissolved Pro-Plus. The participants were unaware of which solution they were consuming, due to the opaque sports bottles they were in, labelled Y and N on the base of the bottle, the solutions were prepared in this design to uphold the validity of the test. The experiment took place at the