Stephen Bird | RMIT University (original) (raw)
Papers by Stephen Bird
Australian Journal of Primary Health, 2010
Journal for Healthcare Quality, 2011
Ultrasound in medicine & biology, Jan 4, 2017
The goal of this study was to determine whether ultrasound measures of muscle architecture can be... more The goal of this study was to determine whether ultrasound measures of muscle architecture can be used to infer strength and functional capacity in older adults. Thirty-six healthy older adults (aged 68.2 ± 5.3 y) undertook isokinetic dynamometry for isometric and isokinetic concentric knee extensor strength, the 6-m fast walk, timed up and go, stair climb and descent and vertical jump tests. Longitudinal brightness-mode ultrasound scans (probe frequency, 10 MHz) of the vastus lateralis, vastus intermedius, rectus femoris and gastrocnemius medialis were obtained, and muscle architecture measures (thickness, fascicle pennation angle and fascicle length) were correlated with the aforementioned strength and functional measures. Quadriceps thickness was a significant (p < 0.05) independent predictor of isometric and isokinetic knee extensor strength (R(2) ≥ 0.630). Gastrocnemius medialis thickness was a significant independent predictor of 6-m fast walk test (R(2) = 0.216, p < 0.0...
European journal of preventive cardiology, Jan 27, 2016
Cardiac rehabilitation is an important component in the continuum of care for individuals with ca... more Cardiac rehabilitation is an important component in the continuum of care for individuals with cardiovascular disease, providing a multidisciplinary education and exercise programme to improve morbidity and mortality risk. Internationally, cardiac rehabilitation programmes are implemented through various models. This review compared cardiac rehabilitation guidelines in order to identify any differences and/or consensus in exercise testing, prescription and monitoring. Guidelines, position statements and policy documents for cardiac rehabilitation, available internationally in the English language, were identified through a search of electronic databases and government and cardiology society websites. Information about programme delivery, exercise testing, prescription and monitoring were extracted and compared. Leading cardiac rehabilitation societies in North America and Europe recommend that patients progress from moderate- to vigorous-intensity aerobic endurance exercise over the...
Australian Health Review a Publication of the Australian Hospital Association, Aug 1, 2007
# Edinburgh Napier University. Home. INSPIRING FUTURES. ...
Journal of Science and Medicine in Sport, 2016
Regular exercise is advocated for individuals with type 2 diabetes, without fully understanding t... more Regular exercise is advocated for individuals with type 2 diabetes, without fully understanding the acute (0-72h post-exercise) glycaemic response. This study assessed post-exercise glycaemic profiles of non-exercising individuals with insulin treated type 2 diabetes, following resistance and aerobic exercise. Randomised cross-over trial. Fourteen individuals with insulin treated type 2 diabetes (9 males, 5 females) aged 58.1±7.1 years (HbA1c: 8.0±0.6%) were allocated to single sessions of resistance (six whole-body exercises, three sets, 8-10 repetitions, 70% 1RM) and aerobic (30min cycling, 60% VO2peak) exercise, 7-days apart, with the day prior to the first exercise day of each intervention being the control condition. Immediately prior to exercise, insulin dosage was halved and breakfast consumed. Continuous glucose monitoring was undertaken to determine area under the curve and glucose excursions. Blood glucose initially increased (0-2h) following both resistance and aerobic exercise (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), peaking at 12.3±3.4mmolL(-1) and 12.3±3.3mmolL(-1), respectively. Area under the glucose curve was not statistically different over any of the 24h periods (p=0.12), or different in response to resistance (222±41mmolL(-1)24h(-1)) or aerobic (211±40 mmolL(-1)24h(-1)) exercise (p=0.56). Incidence of hyperglycaemia did not differ between exercise modes (p=0.68). Hypoglycaemic events were identified in three and four participants following resistance and aerobic exercise respectively: these did not require treatment. Glycaemic response is not different between exercise modes, although 50% insulin dose reduction prior to exercise impairs the expected improvement. A common clinical recommendation of 50% insulin dose reduction does not appear to cause adverse glycaemic events.
Annals of clinical biochemistry, Jan 17, 2015
The use of doping agents are evident within competitive sport in senior and junior age groups, wh... more The use of doping agents are evident within competitive sport in senior and junior age groups, where they are taken by non-elite as well as elite participants. They are also taken in non-sporting contexts by individuals seeking to 'improve' their physique through an increase in muscle and/or decrease in fat mass. Whilst attaining accurate data on the prevalence of their use has limitations, studies suggest the illicit use of doping agents by athletes and non-athletes may be 1 - 5% in the population and greater than 50% in some groups; with the prevalence being higher in males. There is conclusive evidence that some doping agents are anabolic and ergogenic. There is also evidence that the use of doping agents such as: anabolic androgenic steroids; growth hormone and other anabolic agents; erythropoietin; and stimulants conveys considerable health risks that include, but are not limited to: cardiovascular disease, diabetes, cancer, mental health issues, virilisation in women, ...
Journal of applied physiology (Bethesda, Md. : 1985), Jan 25, 2015
We determined the effects of 'periodized nutrition' on skeletal muscle and whole-body res... more We determined the effects of 'periodized nutrition' on skeletal muscle and whole-body responses to a bout of prolonged exercise the following morning. Seven cyclists completed two trials receiving isoenergetic diets differing in the timing of ingestion: They consumed either 8 g•kg(-1) BM of CHO before undertaking an evening session of high-intensity training (HIT) and slept without eating (FASTED), or 4 g•kg(-1) BM of CHO before HIT then 4 g•kg(-1) BM of CHO before sleeping (FED). The next morning subjects completed 2 h cycling (120SS) while overnight fasted. Muscle biopsies were taken on day 1 (D1) before and 2 h after HIT and on Day 2 (D2) pre-, post-, and 4 h after 120SS. Muscle [glycogen] was higher in FED at all times post-HIT (P< 0.001). HIT increased PGC1α mRNA (P< 0.01) while PDK4 mRNA was elevated to a greater extent in FASTED (P< 0.05). Resting phosphorylation of AMPK(Thr172), p38MAPK(Thr180/Tyr182) and p-ACC(Ser79) (D2) was greater in FASTED (P< 0.05)....
Critical Reviews in Physical and Rehabilitation Medicine, 2006
Journal of aging and physical activity, 2005
This study assessed age-related changes in power and heart rate in 114 competitive male cyclists ... more This study assessed age-related changes in power and heart rate in 114 competitive male cyclists age 15-73 years. Participants completed a maximal Kingcycle ergometer test with maximal ramped minute power (RMPmax, W) recorded as the highest average power during any 60 s and maximal heart rate (HRmax, beats/min) as the highest value during the test. From age 15 to 29 (n = 38) RMPmax increased by 7.2 W/year (r = .53, SE 49 W, p < .05). From age 30 to 73 (n = 78) RMPmax declined by 2.4 W/year (r = - .49, SE 49 W, p < .05). Heart rate decreased across the full age range by 0.66 beats . min( -1 ) . year( -1 ) (r = -.75, SE 9 beats/min, p < .05). Age accounted for only 25% of the variance in RMPmax but 56% in HRmax. RMPmax was shown to peak at age 30, then decline with age, whereas HRmax declined across the full age range.
ABSTRACT This study assessed the validity of power output recorded using an air-braked cycle ergo... more ABSTRACT This study assessed the validity of power output recorded using an air-braked cycle ergometer (Kingcycle) when compared with a power measuring crankset (SRM). For part one of the study thirteen physically active subjects completed a continuous incremental exercise test (OBLA), for part two of the study twelve trained cyclists completed two tests; a maximal aerobic power test (MAP) and a 16.1 km time-trial (16.1 km TT). The following were compared; the peak power output (PPO) recorded for 1 min during MAP, the average power output for the duration of the time-trial and power output recorded during each stage of OBLA. For all tests, power output recorded using Kingcycle was significantly higher than SRM (P < 0.001). Ratio limits of agreement between SRM and Kingcycle for OBLA showed a bias (P < 0.00) of 0.90 (95%CI = 0.90-0.91) with a random error of X or / 1.07, and for PPO and 16.1 km TT ratio limits of agreement were 0.90 (95%CI = 0.88-0.92) X or / 1.07 and 0.92 (95% CI = 0.90-0.94) X or / 1.07, respectively. These data revealed that the Kingcycle ergometry system did not provide a valid measure of power output when compared with SRM.
Australian Journal of Primary Health, 2010
Journal for Healthcare Quality, 2011
Ultrasound in medicine & biology, Jan 4, 2017
The goal of this study was to determine whether ultrasound measures of muscle architecture can be... more The goal of this study was to determine whether ultrasound measures of muscle architecture can be used to infer strength and functional capacity in older adults. Thirty-six healthy older adults (aged 68.2 ± 5.3 y) undertook isokinetic dynamometry for isometric and isokinetic concentric knee extensor strength, the 6-m fast walk, timed up and go, stair climb and descent and vertical jump tests. Longitudinal brightness-mode ultrasound scans (probe frequency, 10 MHz) of the vastus lateralis, vastus intermedius, rectus femoris and gastrocnemius medialis were obtained, and muscle architecture measures (thickness, fascicle pennation angle and fascicle length) were correlated with the aforementioned strength and functional measures. Quadriceps thickness was a significant (p < 0.05) independent predictor of isometric and isokinetic knee extensor strength (R(2) ≥ 0.630). Gastrocnemius medialis thickness was a significant independent predictor of 6-m fast walk test (R(2) = 0.216, p < 0.0...
European journal of preventive cardiology, Jan 27, 2016
Cardiac rehabilitation is an important component in the continuum of care for individuals with ca... more Cardiac rehabilitation is an important component in the continuum of care for individuals with cardiovascular disease, providing a multidisciplinary education and exercise programme to improve morbidity and mortality risk. Internationally, cardiac rehabilitation programmes are implemented through various models. This review compared cardiac rehabilitation guidelines in order to identify any differences and/or consensus in exercise testing, prescription and monitoring. Guidelines, position statements and policy documents for cardiac rehabilitation, available internationally in the English language, were identified through a search of electronic databases and government and cardiology society websites. Information about programme delivery, exercise testing, prescription and monitoring were extracted and compared. Leading cardiac rehabilitation societies in North America and Europe recommend that patients progress from moderate- to vigorous-intensity aerobic endurance exercise over the...
Australian Health Review a Publication of the Australian Hospital Association, Aug 1, 2007
# Edinburgh Napier University. Home. INSPIRING FUTURES. ...
Journal of Science and Medicine in Sport, 2016
Regular exercise is advocated for individuals with type 2 diabetes, without fully understanding t... more Regular exercise is advocated for individuals with type 2 diabetes, without fully understanding the acute (0-72h post-exercise) glycaemic response. This study assessed post-exercise glycaemic profiles of non-exercising individuals with insulin treated type 2 diabetes, following resistance and aerobic exercise. Randomised cross-over trial. Fourteen individuals with insulin treated type 2 diabetes (9 males, 5 females) aged 58.1±7.1 years (HbA1c: 8.0±0.6%) were allocated to single sessions of resistance (six whole-body exercises, three sets, 8-10 repetitions, 70% 1RM) and aerobic (30min cycling, 60% VO2peak) exercise, 7-days apart, with the day prior to the first exercise day of each intervention being the control condition. Immediately prior to exercise, insulin dosage was halved and breakfast consumed. Continuous glucose monitoring was undertaken to determine area under the curve and glucose excursions. Blood glucose initially increased (0-2h) following both resistance and aerobic exercise (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), peaking at 12.3±3.4mmolL(-1) and 12.3±3.3mmolL(-1), respectively. Area under the glucose curve was not statistically different over any of the 24h periods (p=0.12), or different in response to resistance (222±41mmolL(-1)24h(-1)) or aerobic (211±40 mmolL(-1)24h(-1)) exercise (p=0.56). Incidence of hyperglycaemia did not differ between exercise modes (p=0.68). Hypoglycaemic events were identified in three and four participants following resistance and aerobic exercise respectively: these did not require treatment. Glycaemic response is not different between exercise modes, although 50% insulin dose reduction prior to exercise impairs the expected improvement. A common clinical recommendation of 50% insulin dose reduction does not appear to cause adverse glycaemic events.
Annals of clinical biochemistry, Jan 17, 2015
The use of doping agents are evident within competitive sport in senior and junior age groups, wh... more The use of doping agents are evident within competitive sport in senior and junior age groups, where they are taken by non-elite as well as elite participants. They are also taken in non-sporting contexts by individuals seeking to 'improve' their physique through an increase in muscle and/or decrease in fat mass. Whilst attaining accurate data on the prevalence of their use has limitations, studies suggest the illicit use of doping agents by athletes and non-athletes may be 1 - 5% in the population and greater than 50% in some groups; with the prevalence being higher in males. There is conclusive evidence that some doping agents are anabolic and ergogenic. There is also evidence that the use of doping agents such as: anabolic androgenic steroids; growth hormone and other anabolic agents; erythropoietin; and stimulants conveys considerable health risks that include, but are not limited to: cardiovascular disease, diabetes, cancer, mental health issues, virilisation in women, ...
Journal of applied physiology (Bethesda, Md. : 1985), Jan 25, 2015
We determined the effects of 'periodized nutrition' on skeletal muscle and whole-body res... more We determined the effects of 'periodized nutrition' on skeletal muscle and whole-body responses to a bout of prolonged exercise the following morning. Seven cyclists completed two trials receiving isoenergetic diets differing in the timing of ingestion: They consumed either 8 g•kg(-1) BM of CHO before undertaking an evening session of high-intensity training (HIT) and slept without eating (FASTED), or 4 g•kg(-1) BM of CHO before HIT then 4 g•kg(-1) BM of CHO before sleeping (FED). The next morning subjects completed 2 h cycling (120SS) while overnight fasted. Muscle biopsies were taken on day 1 (D1) before and 2 h after HIT and on Day 2 (D2) pre-, post-, and 4 h after 120SS. Muscle [glycogen] was higher in FED at all times post-HIT (P< 0.001). HIT increased PGC1α mRNA (P< 0.01) while PDK4 mRNA was elevated to a greater extent in FASTED (P< 0.05). Resting phosphorylation of AMPK(Thr172), p38MAPK(Thr180/Tyr182) and p-ACC(Ser79) (D2) was greater in FASTED (P< 0.05)....
Critical Reviews in Physical and Rehabilitation Medicine, 2006
Journal of aging and physical activity, 2005
This study assessed age-related changes in power and heart rate in 114 competitive male cyclists ... more This study assessed age-related changes in power and heart rate in 114 competitive male cyclists age 15-73 years. Participants completed a maximal Kingcycle ergometer test with maximal ramped minute power (RMPmax, W) recorded as the highest average power during any 60 s and maximal heart rate (HRmax, beats/min) as the highest value during the test. From age 15 to 29 (n = 38) RMPmax increased by 7.2 W/year (r = .53, SE 49 W, p < .05). From age 30 to 73 (n = 78) RMPmax declined by 2.4 W/year (r = - .49, SE 49 W, p < .05). Heart rate decreased across the full age range by 0.66 beats . min( -1 ) . year( -1 ) (r = -.75, SE 9 beats/min, p < .05). Age accounted for only 25% of the variance in RMPmax but 56% in HRmax. RMPmax was shown to peak at age 30, then decline with age, whereas HRmax declined across the full age range.
ABSTRACT This study assessed the validity of power output recorded using an air-braked cycle ergo... more ABSTRACT This study assessed the validity of power output recorded using an air-braked cycle ergometer (Kingcycle) when compared with a power measuring crankset (SRM). For part one of the study thirteen physically active subjects completed a continuous incremental exercise test (OBLA), for part two of the study twelve trained cyclists completed two tests; a maximal aerobic power test (MAP) and a 16.1 km time-trial (16.1 km TT). The following were compared; the peak power output (PPO) recorded for 1 min during MAP, the average power output for the duration of the time-trial and power output recorded during each stage of OBLA. For all tests, power output recorded using Kingcycle was significantly higher than SRM (P < 0.001). Ratio limits of agreement between SRM and Kingcycle for OBLA showed a bias (P < 0.00) of 0.90 (95%CI = 0.90-0.91) with a random error of X or / 1.07, and for PPO and 16.1 km TT ratio limits of agreement were 0.90 (95%CI = 0.88-0.92) X or / 1.07 and 0.92 (95% CI = 0.90-0.94) X or / 1.07, respectively. These data revealed that the Kingcycle ergometry system did not provide a valid measure of power output when compared with SRM.