Cooper, Robert (2013) Analysis of the effects of three commercially available supplements on performance, exercise induced changes and bio-markers in recreationally trained young males. PhD thesis, University of Greenwich.

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Abstract

Commercially available multi-ingredient formulas are ingested by the recreationally trained population to optimise training outcomes; however, there remains no convincing evidence in regards to their effectiveness. Thus, the aim of this project was to analyse the effects of three different multi-ingredient supplements on the expected and marketed outcomes. It was hypothesised that the supplements would potentiate the desired body composition, performance and recovery outcomes as claimed.

Study 1 was conducted to analyse the effects of combining a 12 weeks resistance training programme with the ingestion of a commercially available carbohydrate-protein-creatine based multi-ingredient supplement on strength performance and body omposition in recreationally trained males. It was hypothesised that the ingestion the multi-ingredient supplement would potentiate strength performance adaptations to a greater extent than a maltodextrin placebo. As a secondary hypothesis it was expected that ingesting the multi-ingredient supplement would benefit body composition outcomes in comparison to the placebo. Thirteen healthy male subjects were assigned to either a multi-ingredient formula (n=7) or a carbohydrate placebo (n=6). Both groups ingested the multi-ingredient supplement or placebo in the morning and immediately after training. Before and after the 12 weeks progressive resistance training; percentage body fat and fat free mass were determined. Maximum strength and repetitions to failure with 60% one repetition maximum on bench press and parallel squat were also assessed before and after the resistance training period. No significant increases in any of the performance or body composition variables were observed in either group. However, larger standardised effects sizes and magnitude-based inferences demonstrated that the addition of the multi-ingredient supplement to a 12 week progressive resistance training protocol could be effective to potentiate upper body maximum strength or muscular endurance performance, but not body composition outcomes.
Study 2 was undertaken in order to analyse the acute effects of a commercially available carbohydrate and caffeine gel on intermittent sprint performance in twelve recreationally trained males. It was hypothesised that the combination of carbohydrate and caffeine in gel form would attenuate fatigue and decrease perception of effort when compared to the ingestion of carbohydrate gels alone and placebo gels. A secondary hypothesis postulated that the carbohydrate and caffeine gel would maintain blood glucose levels throughout the intermittent sprint test in regards to both the carbohydrate and placebo gels. Using a cross-over design, one 70 mL dose of gel containing either, 25 g of carbohydrate with or without 100 mg of caffeine or a non-caloric placebo was ingested on three occasions: one hour before, immediately prior and during the intermittent repeated sprint test. Blood glucose, rating of perceived exertion and fatigue index were analysed. The main finding was that ingesting the carbohydrate and caffeine gel one hour before, prior to and during an IST is effective at transiently reducing fatigue and RPE whilst maintaining higher glucose levels at the final stages of the exercise.

Study 3 was conducted in order to analyse the acute effects of a commercially available carbohydrate and protein based multi-ingredient recovery formula on the recovery process and muscle damage, in 10 recreationally trained males, after performing a bout of intermittent sprint exercise. It was hypothesised that the ingestion of a carbohydrate and protein based multi-ingredient supplement, before, during and after an acute bout of intermittent repeated sprint exercise would promote recovery estimated through the attenuation of neuromuscular fatigue and markers of muscle damage respect to the ingestion of carbohydrate only or a low caloric placebo. As a secondary hypothesis the ingestion of the multi nutrient formula would attenuate a decline in sprint performance during the intermittent sprint test when compared to the carbohydrate and placebo conditions. Using a cross-over design, one 500 mL dose of a multi-ingredient recovery beverage, a carbohydrate beverage or a placebo beverage was divided in to 4 equal servings of 125 mL and ingested before each of the 4 blocks of the intermittent sprint test. A second full serving was ingested with 20 minutes of completing the intermittent sprint test. 15m sprint times, creatine kinase, myoglobin, and interleukin-6 were assessed before (pre), immediately post (post), 1 hour and 24 hour after exercise. Total sprint time measured during the intermittent protocol was not different between conditions. 15m sprint time was slower at post, 1 hour and 24 hour compared to pre without differences between conditions. Creatine kinase at 24 hour was lower in the multi-ingredient compared to both carbohydrate and placebo. Myoglobin increased in all three conditions at post, and 1 hour compared to pre, showing lower values at 1 hour for the carbohydrate and approached significance (p=0.060) for multi-ingredient compared to placebo condition. Interleukin-6 increased at both post and 1 hour compared to pre with no differences between conditions. Thus demonstrating, the ingestion of a multi-ingredient supplement before, during and immediately after a 90 min intermittent sprint test resulted in no effects on performance and fatigue. However, the accumulation of some biomarkers of muscle damage could be attenuated.

It would appear that manufacturers make use of the research available to formulate multi-ingredient supplements as the supplements that showed efficacy in studies 1 and 2 possess the most established research. Whereas investigations and knowledge in to the acute effects of a carbohydrate-protein based multi-ingredient supplement on recovery from an intermittent sprint test (study 3) still need to be determined.

Item Type:	Thesis (PhD)
Additional Information:	uk.bl.ethos.616537
Uncontrolled Keywords:	dietary supplements, sports, nutrition, exercise performance,
Subjects:	R Medicine > RM Therapeutics. Pharmacology
Faculty / School / Research Centre / Research Group:	Faculty of Engineering & Science Faculty of Education, Health & Human Sciences > School of Human Sciences (HUM)
Last Modified:	09 Oct 2021 04:46
URI:	http://gala.gre.ac.uk/id/eprint/11949

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