- Liittynyt
- 30.8.2002
- Viestejä
- 587
Paul Cribbin väitöskirja: “Dietary supplementation & resistance training programs designed to promote increases in muscle mass” ladattavissa, klikkaa tästä.
Abstrakti:
Lifestyle strategies that focus on building/preserving skeletal muscle mass will enhance the health of a wide sector of the population and possibly, diminish the severity of many ageing-related illnesses. The focus of this dissertation was to examine the effects of strategic intervention with dietary supplements and exercise designed specifically to promote an increase in muscle mass (hypertrophy). Three separate trials were completed using healthy adult males (aged 18-36 years). Each trial utilized a randomized, double-blinded design that involved 10-11 weeks of structured RE training and matched groups that supplemented their diets with whey protein (WP), creatine monohydrate (CrM) and/or carbohydrate (CHO) (separately and in various combinations as well as at strategic times of the day). Assessments included body composition (lean mass, fat mass and body fat %), maximum (absolute) strength in three weight lifting exercises, and vastus lateralis muscle biopsies for determination of muscle fibre types (I, IIa and IIx), cross-sectional area (CSA), energy metabolite and glycogen concentrations as well as contractile protein content. The results of study-1 (chapter-3), demonstrated that despite the consumption of a high protein intake by all groups and no differences between the groups before the study, supplementation with CrM and/or WP resulted in greater (P < 0.05) improvements in strength (in three assessments) compared to supplementation with an equivalent dose of CHO. These improvements correlated strongly (r ≥0.7; P < 0.01) with the differences (P < 0.05) in skeletal muscle morphology that were detected among the groups. The
results from study-2 (chapter-4) demonstrated that a CrM-containing WP-CHO supplement provided a significantly greater improvement in body composition (increase in lean mass and decrease in body fat %; P < 0.05), greater gains in strength and muscle hypertrophy (type-IIa and IIx muscle fibre CSA and contractile protein content; P < 0.05) compared to a group given the same supplement without CrM. In study-3 (chapter 5) the effects of supplement-timing (i.e., the strategic consumption of a WP-CrM supplement immediately before and after exercise) was compared to the consumption of the same supplement at times outside of the pre- and post-workout period. Supplement-timing
resulted in a better improvement in body composition (P < 0.05), greater gains in strength (in 2 out of the 3 assessments) (P < 0.05) and muscle hypertrophy (P < 0.05). Very few studies involving exercise training and supplementation have reported favourable changes in body composition alongside alterations at the cellular (fibre type specific hypertrophy) and subcellular (contractile protein content) levels. The research provides data on non-pharmaceutical, cost-effective strategies that could be easily implemented by a wide sector of the population to build/maintain muscle mass throughout the lifespan, and therefore, reduce the severity of many ageing-related illnesses as well as the economic burden on the health care system.
Abstrakti:
Lifestyle strategies that focus on building/preserving skeletal muscle mass will enhance the health of a wide sector of the population and possibly, diminish the severity of many ageing-related illnesses. The focus of this dissertation was to examine the effects of strategic intervention with dietary supplements and exercise designed specifically to promote an increase in muscle mass (hypertrophy). Three separate trials were completed using healthy adult males (aged 18-36 years). Each trial utilized a randomized, double-blinded design that involved 10-11 weeks of structured RE training and matched groups that supplemented their diets with whey protein (WP), creatine monohydrate (CrM) and/or carbohydrate (CHO) (separately and in various combinations as well as at strategic times of the day). Assessments included body composition (lean mass, fat mass and body fat %), maximum (absolute) strength in three weight lifting exercises, and vastus lateralis muscle biopsies for determination of muscle fibre types (I, IIa and IIx), cross-sectional area (CSA), energy metabolite and glycogen concentrations as well as contractile protein content. The results of study-1 (chapter-3), demonstrated that despite the consumption of a high protein intake by all groups and no differences between the groups before the study, supplementation with CrM and/or WP resulted in greater (P < 0.05) improvements in strength (in three assessments) compared to supplementation with an equivalent dose of CHO. These improvements correlated strongly (r ≥0.7; P < 0.01) with the differences (P < 0.05) in skeletal muscle morphology that were detected among the groups. The
results from study-2 (chapter-4) demonstrated that a CrM-containing WP-CHO supplement provided a significantly greater improvement in body composition (increase in lean mass and decrease in body fat %; P < 0.05), greater gains in strength and muscle hypertrophy (type-IIa and IIx muscle fibre CSA and contractile protein content; P < 0.05) compared to a group given the same supplement without CrM. In study-3 (chapter 5) the effects of supplement-timing (i.e., the strategic consumption of a WP-CrM supplement immediately before and after exercise) was compared to the consumption of the same supplement at times outside of the pre- and post-workout period. Supplement-timing
resulted in a better improvement in body composition (P < 0.05), greater gains in strength (in 2 out of the 3 assessments) (P < 0.05) and muscle hypertrophy (P < 0.05). Very few studies involving exercise training and supplementation have reported favourable changes in body composition alongside alterations at the cellular (fibre type specific hypertrophy) and subcellular (contractile protein content) levels. The research provides data on non-pharmaceutical, cost-effective strategies that could be easily implemented by a wide sector of the population to build/maintain muscle mass throughout the lifespan, and therefore, reduce the severity of many ageing-related illnesses as well as the economic burden on the health care system.
