Reporting accurate and reliable measures of pressure exerted by sport compression clothing assist... more Reporting accurate and reliable measures of pressure exerted by sport compression clothing assists in the interpretation and comparison of study findings. The objective of the current study was to assess the validity and reliability of the Kikuhime pressure monitoring device to measure the pressure of sport compression garments. To assess validity, three separate Kikuhime sensors were compared to known pressures inside a water column, at 5 mmHg increments ranging from 5 to 100 mmHg. Intra- and inter-tester reliability was determined by comparing the results of two individuals performing five interface pressure measures at six different landmarks across the lower and upper leg of an athlete wearing sports compression leggings. All three sensors tested exhibited a very high intra-class correlation with the reference value (mean ICC = 0.996). The typical error of measurement was low for both intra- and inter-tester reliability (mean ± SD: 1.3 ± 0.9 and 1.8 ± 0.9 mmHg, respectively). These results expressed as a coefficient of variation were 4.9 ± 2.4 and 7.4 ± 5.4 %, respectively. The findings from the current study suggest that the Kikuhime device is a valid and reliable instrument for use in situ when measuring the pressure of sports compression garments in athletes assuming a static standing posture. The instrument could be used in future research involving compression garments to accurately quantify interface pressures and their subsequent effect on physiological and/or performance measures.
Background Sarcopenia, the age-related decline in skeletal muscle mass and function, is a relativ... more Background Sarcopenia, the age-related decline in skeletal muscle mass and function, is a relatively poorly understood process which may play an important role in the incidence of physical disability and falls in older adults. Evidence demonstrates that both genetic and environmental factors contribute to increased susceptibility for sarcopenia development, yet some of these factors may represent unavoidable consequences of ageing. Methods A review of literature, generally from epidemiological research, was performed to examine the influence that potentially modifiable lifestyle factors (general physical activity, dietary nutrient intake and sun exposure), as well as chronic disease and medication use, may have on sarcopenia progression. Results The review demonstrated that while physical activity, nutrient intake and sun exposure often decline during ageing, each may have important but differing benefits for the prevention of muscle mass and functional declines in older adults. Conversely, age-related increases in the prevalence of chronic diseases and the subsequent prescription of pharmacotherapy may exacerbate sarcopenia progression.
ABSTRACT This study investigated the effect of Pilates exercise on physical fall risk factors 12 ... more ABSTRACT This study investigated the effect of Pilates exercise on physical fall risk factors 12 months after an initial 5 week Pilates intervention. We hypothesised that ongoing Pilates participation would have a positive effect on physical fall risk factors in those that continued with the Pilates exercise compared with those that ceased. Thirty older ambulatory adults (69±7yrs) participated in Pilates classes for 5 weeks with testing pre (T1) and post-intervention (T2), and 12 months later (T3). Balance and leg strength were compared using a two-way ANOVA with repeated measures. Postural sway, dynamic balance and function improvements evident after the initial Pilates training (T1-T2), were maintained at T3 (P<0.01). Significant differences existed at T3 for dynamic balance and strength between participants who continued performing Pilates (N=14) and those who had ceased. Balance improvements after a short Pilates intervention were maintained one year later in all participants, with increased benefits from ongoing participation.
International journal of sport nutrition and exercise metabolism, 2015
Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popula... more Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popular despite a paucity of supportive medical or ergogenic evidence. This study aimed to quantify the demographics of NCA and determine associated experiences, perceptions, and sources of information related to GFD. Athletes (n = 910, female = 528, no gender selected = 5) completed a 17-question online survey. Forty-one percent of NCA respondents, including 18-world and/or Olympic medalists, follow a GFD 50-100% of the time (GFD > 50): only 13% for treatment of reported medical conditions with 57% self-diagnosing their gluten sensitivity. The GFD > 50 group characteristics included predominantly endurance sport athletes (70.0%) at the recreationally competitive level (32.3%), between 31 and 40 years of age (29.1%). Those who follow a GFD > 50 reported experiencing, abdominal/gastrointestinal (GI) symptoms alone (16.7%) or in conjunction with two (30.7%) or three (35.7%) additional s...
To describe rates of occurrence of falls, injuries and fatalities to horse-racing jockeys in Aust... more To describe rates of occurrence of falls, injuries and fatalities to horse-racing jockeys in Australia. Retrospective analysis of data on race-day falls from stewards' reports provided by the Principal Racing Authority of each state and territory of Australia, August 2002 - July 2006. Fall, injury and fatality incidence rates; comparison with overseas rates. There were 3360 jockey falls from 748 367 rides. Falls occurred at a rate of 0.42 per 100 rides in flat races and 5.26 per 100 rides in jumps races. In flat racing, 54.6% (1694/3101) of falls occurred before the start of the race and 11.1% (344/3101) of falls occurred post-race. The 34.3% (1063/3101) of falls that occurred during flat races resulted in 61.7% (516/836) of the injuries sustained. In jumps racing, most falls occurred at a jump and 9.7% (25/259) of jockeys who fell were transported to hospital and/or declared unfit to ride. There were five fatalities resulting from falls during the study period, all in flat raci...
The Journal of sports medicine and physical fitness, 2008
This study investigated whether ageing effects perceived and reported ratings of fatigue and tota... more This study investigated whether ageing effects perceived and reported ratings of fatigue and total quality of recovery following high-intensity training in athletes. We hypothesized that veteran (V) athletes would report greater changes in perceived measures of fatigue and recovery than training-matched younger athletes. Perceptions of muscle soreness (SOR), fatigue, and recovery were recorded in young (Y) and V (>35 years) well-trained cyclists in response to 3 days of repeated cycling time trials. Nine Y (24+/-5 years) and 9 V (45+/-6 years) cyclists performed 3 consecutive days (T1-T3) of 30-min cycling time trials (TT30) intended to induce fatigue leading to decreased performance. Physiological and performance variables were measured before, during, and after each time trial. Subjective measures of SOR, fatigue, and recovery were recorded each day. There was no change in performance at the TT30 from T1 to T3 for either group. SOR, fatigue, and recovery significantly changed o...
Recovery from exercise is integral to the physical training process. There is a perception among ... more Recovery from exercise is integral to the physical training process. There is a perception among older athletes that aging negatively affects the recovery process. Plausible arguments for an impaired recovery with aging are a greater susceptibility of older muscle to exercise-induced skeletal-muscle damage and a slower repair and adaptation response. Differences in the physical activity level of the research participants are rarely considered, however. This makes it difficult to differentiate the respective roles of declining physical activity and aging on the recovery process. Furthermore, the type of exercise used to induce damage and monitor recovery is often not indicative of a normal training stimulus for athletes. This review discusses the effects of aging on skeletal-muscle damage and recovery processes and highlights the limitations of many of these studies with respect to older athletes. Future research should use an exercise intervention representative of a normal training...
The Journal of sports medicine and physical fitness, 2006
There is a common belief amongst athletes and coaches that older athletes need longer recovery ti... more There is a common belief amongst athletes and coaches that older athletes need longer recovery time between training sessions and following competition. This study was undertaken to investigate the influence of age on recovery from high intensity endurance exercise in well-trained cyclists. Nine young and 9 veteran cyclists (mean+/-SD: young 24+/-5 years, veteran 45+/-6 years) performed 3 consecutive days (T1-T3) of laboratory based cycling time trials of 30-min duration (TT30). Mean power output, heart rate (HR), and blood lactate were measured throughout each TT30. Non-specific performance tests of fatigue were undertaken before and after the TT30 on each test day. Non-specific tests included, a maximal voluntary isometric contraction of the quadriceps muscle (MVIF), a countermovement jump (CMJ), a 10-s cycle sprint (10ST), and serum creatine kinase activity (CK). Statistical analysis revealed that there were no significant group differences between young and veteran subjects for ...
Australian journal of science and medicine in sport, 1996
The physiological profiles and proficiency of 32 volunteer surf life savers (LS), 15 professional... more The physiological profiles and proficiency of 32 volunteer surf life savers (LS), 15 professional lifeguards (LG), and 8 elite surf ironmen (IM) aged from 18 to 44 were compared. Measurements included anthropometry, muscular power, muscular strength-endurance, flexibility, VO2max, maximum heart rate, peak blood lactate response and proficiency in 3 rescue simulations. Both LG and IM were significantly faster than LS in all rescue simulations. IM had significantly greater VO2max (68.6 ml.kg-1.min-1) than LS (56.3) and LG (57.9). IM had significantly lower heart rates than LS after maximal swimming and running, and significantly lower blood lactate 3 minutes post swim (8.4 mmol/L) in comparison with LS (14.0) and LG (12.2). LG obtained better results than LS in 2 of the 3 muscular strength-endurance tasks. It is concluded that: LG and IM are significantly faster in aquatic rescue simulations than LS; IM have greater aerobic capacities than both other groups; the majority of Australian...
International journal of sport nutrition and exercise metabolism, 2013
Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this ran... more Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7 kg; VO2max = 67 ± 4 ml · kg(-1) · min(-1)) supplemented with either beta-alanine (n = 8, 65 mg · kg - 1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180° · sec(-1) to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La-) and bicarbonate (HCO3-) concentrations were measured pre- and postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% like...
International Journal of Sport Nutrition and Exercise Metabolism, 2014
The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved ... more The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved endurance cycling time-trial performance in well-trained cyclists. It was hypothesized that caffeine exposure at the mouth would enhance endurance cycling time-trial performance. Ten well-trained male cyclists (mean± SD: 32.9 ± 7.5 years, 74.7 ± 5.3kg, 176.8 ± 5.1cm, VO 2peak = 59.8 ± 3.5ml·kg -1 ·min -1 ) completed two experimental timetrials following 24 hr of dietary and exercise standardization. A randomized, double-blind, placebo-controlled, cross-over design was employed whereby cyclists completed a time-trial in the fastest time possible, which was equivalent work to cycling at 75% of peak aerobic power output for 60 min. Cyclists were administered 25ml mouth-rinses for 10 s containing either placebo or 35mg of anhydrous caffeine eight times throughout the time-trial. Perceptual and physiological variables were recorded throughout. No significant improvement in time-trial performance was observed with caffeine (3918 ± 243s) compared with placebo mouth-rinse (3940 ± 227s). No elevation in plasma caffeine was detected due to the mouth-rinse conditions. Caffeine mouth-rinse had no significant effect on rating of perceived exertion, heart rate, rate of oxygen consumption or blood lactate concentration. Eight exposures of a 35 mg dose of caffeine at the buccal cavity for 10s does not significantly enhance endurance cycling time-trial performance, nor does it elevate plasma caffeine concentration.
International journal of sport nutrition and exercise metabolism, 2009
Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat los... more Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat loss. The authors examined the effects of exercise intensity, duration, and modality on postexercise oxygen consumption (VO2) and substrate selection/ respiratory-exchange ratio (RER) in healthy individuals. Three experiments (n = 7 for each) compared (a) short- (SD) vs. long-duration (LD) ergometer cycling exercise (30 min vs. 90 min) matched for intensity, (b) low- (LI) vs. high-intensity (HI) cycling (50% vs. 85% of VO2(max)) matched for energy expenditure, and (c) continuous (CON) vs. interval (INT) cycling matched for energy expenditure and mean intensity. All experiments were administered by crossover design. Altering exercise duration did not affect postexercise VO2 or RER kinetics (p > .05). However, RER was lower and fat oxidation was higher during the postexercise period in LD vs. SD (p < .05). HI vs. LI resulted in a significant increase in total postexercise energy expendi...
Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this ran... more Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7kg; VO 2max = 67 ± 4ml·kg -1 ·min-1 ) supplemented with either beta-alanine (n = 8, 65 mg·kg -1 BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre-and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180°·sec -1 to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La -) and bicarbonate (HCO 3 -) concentrations were measured preand postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9W, placebo: -4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO 3between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.
Reporting accurate and reliable measures of pressure exerted by sport compression clothing assist... more Reporting accurate and reliable measures of pressure exerted by sport compression clothing assists in the interpretation and comparison of study findings. The objective of the current study was to assess the validity and reliability of the Kikuhime pressure monitoring device to measure the pressure of sport compression garments. To assess validity, three separate Kikuhime sensors were compared to known pressures inside a water column, at 5 mmHg increments ranging from 5 to 100 mmHg. Intra- and inter-tester reliability was determined by comparing the results of two individuals performing five interface pressure measures at six different landmarks across the lower and upper leg of an athlete wearing sports compression leggings. All three sensors tested exhibited a very high intra-class correlation with the reference value (mean ICC = 0.996). The typical error of measurement was low for both intra- and inter-tester reliability (mean ± SD: 1.3 ± 0.9 and 1.8 ± 0.9 mmHg, respectively). These results expressed as a coefficient of variation were 4.9 ± 2.4 and 7.4 ± 5.4 %, respectively. The findings from the current study suggest that the Kikuhime device is a valid and reliable instrument for use in situ when measuring the pressure of sports compression garments in athletes assuming a static standing posture. The instrument could be used in future research involving compression garments to accurately quantify interface pressures and their subsequent effect on physiological and/or performance measures.
Background Sarcopenia, the age-related decline in skeletal muscle mass and function, is a relativ... more Background Sarcopenia, the age-related decline in skeletal muscle mass and function, is a relatively poorly understood process which may play an important role in the incidence of physical disability and falls in older adults. Evidence demonstrates that both genetic and environmental factors contribute to increased susceptibility for sarcopenia development, yet some of these factors may represent unavoidable consequences of ageing. Methods A review of literature, generally from epidemiological research, was performed to examine the influence that potentially modifiable lifestyle factors (general physical activity, dietary nutrient intake and sun exposure), as well as chronic disease and medication use, may have on sarcopenia progression. Results The review demonstrated that while physical activity, nutrient intake and sun exposure often decline during ageing, each may have important but differing benefits for the prevention of muscle mass and functional declines in older adults. Conversely, age-related increases in the prevalence of chronic diseases and the subsequent prescription of pharmacotherapy may exacerbate sarcopenia progression.
ABSTRACT This study investigated the effect of Pilates exercise on physical fall risk factors 12 ... more ABSTRACT This study investigated the effect of Pilates exercise on physical fall risk factors 12 months after an initial 5 week Pilates intervention. We hypothesised that ongoing Pilates participation would have a positive effect on physical fall risk factors in those that continued with the Pilates exercise compared with those that ceased. Thirty older ambulatory adults (69±7yrs) participated in Pilates classes for 5 weeks with testing pre (T1) and post-intervention (T2), and 12 months later (T3). Balance and leg strength were compared using a two-way ANOVA with repeated measures. Postural sway, dynamic balance and function improvements evident after the initial Pilates training (T1-T2), were maintained at T3 (P&lt;0.01). Significant differences existed at T3 for dynamic balance and strength between participants who continued performing Pilates (N=14) and those who had ceased. Balance improvements after a short Pilates intervention were maintained one year later in all participants, with increased benefits from ongoing participation.
International journal of sport nutrition and exercise metabolism, 2015
Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popula... more Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popular despite a paucity of supportive medical or ergogenic evidence. This study aimed to quantify the demographics of NCA and determine associated experiences, perceptions, and sources of information related to GFD. Athletes (n = 910, female = 528, no gender selected = 5) completed a 17-question online survey. Forty-one percent of NCA respondents, including 18-world and/or Olympic medalists, follow a GFD 50-100% of the time (GFD > 50): only 13% for treatment of reported medical conditions with 57% self-diagnosing their gluten sensitivity. The GFD > 50 group characteristics included predominantly endurance sport athletes (70.0%) at the recreationally competitive level (32.3%), between 31 and 40 years of age (29.1%). Those who follow a GFD > 50 reported experiencing, abdominal/gastrointestinal (GI) symptoms alone (16.7%) or in conjunction with two (30.7%) or three (35.7%) additional s...
To describe rates of occurrence of falls, injuries and fatalities to horse-racing jockeys in Aust... more To describe rates of occurrence of falls, injuries and fatalities to horse-racing jockeys in Australia. Retrospective analysis of data on race-day falls from stewards' reports provided by the Principal Racing Authority of each state and territory of Australia, August 2002 - July 2006. Fall, injury and fatality incidence rates; comparison with overseas rates. There were 3360 jockey falls from 748 367 rides. Falls occurred at a rate of 0.42 per 100 rides in flat races and 5.26 per 100 rides in jumps races. In flat racing, 54.6% (1694/3101) of falls occurred before the start of the race and 11.1% (344/3101) of falls occurred post-race. The 34.3% (1063/3101) of falls that occurred during flat races resulted in 61.7% (516/836) of the injuries sustained. In jumps racing, most falls occurred at a jump and 9.7% (25/259) of jockeys who fell were transported to hospital and/or declared unfit to ride. There were five fatalities resulting from falls during the study period, all in flat raci...
The Journal of sports medicine and physical fitness, 2008
This study investigated whether ageing effects perceived and reported ratings of fatigue and tota... more This study investigated whether ageing effects perceived and reported ratings of fatigue and total quality of recovery following high-intensity training in athletes. We hypothesized that veteran (V) athletes would report greater changes in perceived measures of fatigue and recovery than training-matched younger athletes. Perceptions of muscle soreness (SOR), fatigue, and recovery were recorded in young (Y) and V (>35 years) well-trained cyclists in response to 3 days of repeated cycling time trials. Nine Y (24+/-5 years) and 9 V (45+/-6 years) cyclists performed 3 consecutive days (T1-T3) of 30-min cycling time trials (TT30) intended to induce fatigue leading to decreased performance. Physiological and performance variables were measured before, during, and after each time trial. Subjective measures of SOR, fatigue, and recovery were recorded each day. There was no change in performance at the TT30 from T1 to T3 for either group. SOR, fatigue, and recovery significantly changed o...
Recovery from exercise is integral to the physical training process. There is a perception among ... more Recovery from exercise is integral to the physical training process. There is a perception among older athletes that aging negatively affects the recovery process. Plausible arguments for an impaired recovery with aging are a greater susceptibility of older muscle to exercise-induced skeletal-muscle damage and a slower repair and adaptation response. Differences in the physical activity level of the research participants are rarely considered, however. This makes it difficult to differentiate the respective roles of declining physical activity and aging on the recovery process. Furthermore, the type of exercise used to induce damage and monitor recovery is often not indicative of a normal training stimulus for athletes. This review discusses the effects of aging on skeletal-muscle damage and recovery processes and highlights the limitations of many of these studies with respect to older athletes. Future research should use an exercise intervention representative of a normal training...
The Journal of sports medicine and physical fitness, 2006
There is a common belief amongst athletes and coaches that older athletes need longer recovery ti... more There is a common belief amongst athletes and coaches that older athletes need longer recovery time between training sessions and following competition. This study was undertaken to investigate the influence of age on recovery from high intensity endurance exercise in well-trained cyclists. Nine young and 9 veteran cyclists (mean+/-SD: young 24+/-5 years, veteran 45+/-6 years) performed 3 consecutive days (T1-T3) of laboratory based cycling time trials of 30-min duration (TT30). Mean power output, heart rate (HR), and blood lactate were measured throughout each TT30. Non-specific performance tests of fatigue were undertaken before and after the TT30 on each test day. Non-specific tests included, a maximal voluntary isometric contraction of the quadriceps muscle (MVIF), a countermovement jump (CMJ), a 10-s cycle sprint (10ST), and serum creatine kinase activity (CK). Statistical analysis revealed that there were no significant group differences between young and veteran subjects for ...
Australian journal of science and medicine in sport, 1996
The physiological profiles and proficiency of 32 volunteer surf life savers (LS), 15 professional... more The physiological profiles and proficiency of 32 volunteer surf life savers (LS), 15 professional lifeguards (LG), and 8 elite surf ironmen (IM) aged from 18 to 44 were compared. Measurements included anthropometry, muscular power, muscular strength-endurance, flexibility, VO2max, maximum heart rate, peak blood lactate response and proficiency in 3 rescue simulations. Both LG and IM were significantly faster than LS in all rescue simulations. IM had significantly greater VO2max (68.6 ml.kg-1.min-1) than LS (56.3) and LG (57.9). IM had significantly lower heart rates than LS after maximal swimming and running, and significantly lower blood lactate 3 minutes post swim (8.4 mmol/L) in comparison with LS (14.0) and LG (12.2). LG obtained better results than LS in 2 of the 3 muscular strength-endurance tasks. It is concluded that: LG and IM are significantly faster in aquatic rescue simulations than LS; IM have greater aerobic capacities than both other groups; the majority of Australian...
International journal of sport nutrition and exercise metabolism, 2013
Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this ran... more Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7 kg; VO2max = 67 ± 4 ml · kg(-1) · min(-1)) supplemented with either beta-alanine (n = 8, 65 mg · kg - 1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180° · sec(-1) to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La-) and bicarbonate (HCO3-) concentrations were measured pre- and postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% like...
International Journal of Sport Nutrition and Exercise Metabolism, 2014
The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved ... more The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved endurance cycling time-trial performance in well-trained cyclists. It was hypothesized that caffeine exposure at the mouth would enhance endurance cycling time-trial performance. Ten well-trained male cyclists (mean± SD: 32.9 ± 7.5 years, 74.7 ± 5.3kg, 176.8 ± 5.1cm, VO 2peak = 59.8 ± 3.5ml·kg -1 ·min -1 ) completed two experimental timetrials following 24 hr of dietary and exercise standardization. A randomized, double-blind, placebo-controlled, cross-over design was employed whereby cyclists completed a time-trial in the fastest time possible, which was equivalent work to cycling at 75% of peak aerobic power output for 60 min. Cyclists were administered 25ml mouth-rinses for 10 s containing either placebo or 35mg of anhydrous caffeine eight times throughout the time-trial. Perceptual and physiological variables were recorded throughout. No significant improvement in time-trial performance was observed with caffeine (3918 ± 243s) compared with placebo mouth-rinse (3940 ± 227s). No elevation in plasma caffeine was detected due to the mouth-rinse conditions. Caffeine mouth-rinse had no significant effect on rating of perceived exertion, heart rate, rate of oxygen consumption or blood lactate concentration. Eight exposures of a 35 mg dose of caffeine at the buccal cavity for 10s does not significantly enhance endurance cycling time-trial performance, nor does it elevate plasma caffeine concentration.
International journal of sport nutrition and exercise metabolism, 2009
Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat los... more Postexercise fat oxidation may be important for exercise prescription aimed at optimizing fat loss. The authors examined the effects of exercise intensity, duration, and modality on postexercise oxygen consumption (VO2) and substrate selection/ respiratory-exchange ratio (RER) in healthy individuals. Three experiments (n = 7 for each) compared (a) short- (SD) vs. long-duration (LD) ergometer cycling exercise (30 min vs. 90 min) matched for intensity, (b) low- (LI) vs. high-intensity (HI) cycling (50% vs. 85% of VO2(max)) matched for energy expenditure, and (c) continuous (CON) vs. interval (INT) cycling matched for energy expenditure and mean intensity. All experiments were administered by crossover design. Altering exercise duration did not affect postexercise VO2 or RER kinetics (p > .05). However, RER was lower and fat oxidation was higher during the postexercise period in LD vs. SD (p < .05). HI vs. LI resulted in a significant increase in total postexercise energy expendi...
Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this ran... more Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7kg; VO 2max = 67 ± 4ml·kg -1 ·min-1 ) supplemented with either beta-alanine (n = 8, 65 mg·kg -1 BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre-and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180°·sec -1 to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La -) and bicarbonate (HCO 3 -) concentrations were measured preand postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9W, placebo: -4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO 3between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.
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Papers by James Fell