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Results, discussions

The main stages of a discussion were introduced in the previous section. In a critical reading of results and discussion you will be assessing how well the argument is built up. This means judging the importance of the key results and the validity of the claims made. Are the claims supported by other research studies and what are the implications of the research? Here are the results and extracts from the discussion sections of the article by Wiles, J. D., Coleman, D., Tegerdine, M. and Swaine, I. L. (2006) The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1 km cycling time-trial, Journal of Sports Sciences, 24 (11):1165 –1171.


Caffeine ingestion resulted in improved cycling performance time (caffeine vs. placebo vs. control: 71.1 ± 2.0 vs. 73.4 ± 2.3 vs. 73.3 ± 2.7 s; P = 0.02; mean ± s) and speed to complete the 1 km trial (caffeine vs. placebo vs. control: 50.7 ± 1.4 vs. 49.1 ± 1.5 vs. 49.2 ±1.7 kmh-1; P = 0.0005). An improvement in performance time was observed in seven of eight cyclists and represented a 3.1% (95% confidence interval = 0.7 –5.6) improvement compared with the placebo trial. Mean power increased after caffeine ingestion (caffeine vs. placebo vs. control: 523 ± 43 vs. 505 ± 46 vs. 504 ± 38W; P = 0.007). Peak power also increased from 864 ± 107W (placebo) and 830 ± 87W (control) to 940 ± 83W after caffeine ingestion (P = 0.027). Again, increases in mean power and peak power were observed in seven of eight participants. These increases represented 3.6% (95% confidence interval = 1.3–5.8) for mean power and 8.8% (95% confidence interval 1.3–16.4) for peak power respectively, when expressed relative to placebo. The results are shown in Table 1. Each individual’s response to caffeine ingestion is presented in Figures 1, 2 and 3 for performance time, mean power and peak power respectively.

Table 1, and Figures 1, 2 and 3 have been omitted.

Select the most appropriate critical comment on the discussion extracts from the right hand column. When you have finished click Submit to check your answers.

Discussion stage Discussion extract Critical comment
RELATE TO AIM OR PURPOSE The aim of this study was to assess the effects of caffeine ingestion on cycling performance during a 1 km time-trial  
RESTATE/EXPLAIN RESULTS The results indicate a significant improvement in performance time (2.3 s), speed (1.6 kmh-1), mean power (18.1W) and peak power (75.5W), when compared with a placebo, following caffeine ingestion in this group of trained cyclists. 1. The results are
clearly explained
Note too, that the results here are presented more generally than in the Results section.

The significance of these findings is emphasized when one considers the range of times recorded in the 1 km event at the XXVIII Olympiad (Athens, 2004). During this championship, 17 competitors completed the 1 km time-trial and 2.39 s was the difference in performance time between the winner and the rider finishing in tenth place. The winning margin (1st vs. 2nd) was a slender 0.185 s (0.31%). Although the cyclists participating in the current study were approximately 10 s slower during the ergometer simulated 1 km time-trials than the best riders in the world over this distance, the data from the XXVIII Olympiad indicate that very small gains in time/speed and power in this event could influence the overall result.

In light of our findings, the recent lifting of the ban on the use of caffeine is surprising (World Anti- Doping Agency, January 2004). Previously, Spriet (1995) had raised the ethical considerations associated with the ergogenic effects of caffeine in a review of its effects upon sports performance. The suggestion was that caffeine, even at low doses, should be added to the list of banned substances by the International Olympic Committee (IOC), and that athletes be required to abstain from caffeine ingestion 48–72 h before competition. Our results support the suggestion that the advantages conferred by caffeine could be extended from the well-documented effects upon “endurance” events to shorter athletic events lasting 60 s or more. Therefore, our results provide further evidence to support the idea that there is the potential for abuse of caffeine in a much wider range of athletic events than previously thought.

2. The results make a
strong correct
claim about their importance.

3. The authors’ attitude to lifting the ban on the use of caffeine is
positive wrong
Their words: “is surprising”, based on their findings and recommendations from other research.

4. The authors’ research
does not supportcorrect
the lifting of the IOC ban on the use of caffeine.
This is because of the advantages caffeine confers.

5. The authors claim that their research has implications for
a wide range of athletic eventscorrect

DISCUSS LIMITATIONS Although our study was restricted to an assessment of changes in performance, and we did not make measurements that might identify the mechanisms responsible for such changes, there are several possible explanations based upon the results of previous work. Bruce et al. (2000) suggested that the effects of caffeine are probably exerted through effects upon the central nervous system or skeletal muscle by greater motor unit recruitment and alterations in neurotransmitter function (Kalmar & Cafarelli, 1999; Wilson, 1975). Indeed, Doherty et al. (2002) found attenuated post-exercise plasma potassium concentrations following caffeine ingestion during short-duration high-intensity exercise. They inferred that if plasma potassium concentration represents skeletal muscle efflux, then caffeine ingestion could result in greater motor unit activation and/or enhanced force production per motor unit during this type of activity. 6. The authors mention the limitiations of their resesarch

but do not justify them.correct
They do not justify why they did not measure the mechanisms involved in metabolic changes but simply discuss previous research which could explain such changes.
REFER OTHER RESEARCH The improvements in power in our cyclists after caffeine ingestion (3.6%) are similar to those reported by Bruce et al. (2000) for elite oarsmen (2.7% increase in mean power in a 2000m rowing test). The improvements in power in their study represented about 2.5 times the improvement in performance time, whereas in our study the improvements in performance time were matched by improvements in power. This might be explained by the respective relationships between power and speed using a rowing ergometer (Concept II, Model B, Morrisville, VT) versus the SRM cycling ergometer used in this study. 7. The authors’ findings
are supportedcorrect
are not supportedwrong
by relevant previous research.
However, the support is tentative as previous research on rowers is treated cautiously due to differences in cycling and rowing ergometer equipment.

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