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There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of approximately 60 s duration. To address this, eight trained cyclists... more
There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of approximately 60 s duration. To address this, eight trained cyclists performed a 1 km time-trial on an electronically braked cycle ergometer under three conditions: after ingestion of 5 mg x kg-1 caffeine, after ingestion of a placebo, or a control condition. The three time-trials were performed in a randomized order and performance time, mean speed, mean power and peak power were determined. Caffeine ingestion resulted in improved 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). This change represented a 3.1% (95% confidence interval: 0.7-5.6) improvement compared with the placebo condition. Mean speed was also higher in the caffeine than placebo and control conditions (caffeine vs. placebo vs. control: 50.7 +/- 1.4 vs. 49.1 +/- 1.5 vs. 49.2 +/- 1.7 km x h-1; P = 0.0005). Mean power increased after caffeine ingestion (caffeine vs. placebo vs. control: 523 +/- 43 vs. 505 +/- 46 vs. 504 +/- 38 W; P = 0.007). Peak power also increased from 864 +/- 107 W (placebo) and 830 +/- 87 W (control) to 940 +/- 83 W after caffeine ingestion (P = 0.027). These results provide support for previous research that found improved performance after caffeine ingestion during short-duration high-intensity exercise. The magnitude of the improvements observed in our study could be due to our use of sport-specific ergometry, a tablet form and trained participants.
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The purpose of this study was (a) to assess lactate accumulation during isometric exercise, and to quantify the shifts in accumulation following isometric training; and (b) to relate any training-induced changes in lactate accumulation to... more
The purpose of this study was (a) to assess lactate accumulation during isometric exercise, and to quantify the shifts in accumulation following isometric training; and (b) to relate any training-induced changes in lactate accumulation to reductions in resting blood pressure. Eleven male participants undertook isometric training for a 4-week period using bilateral-leg exercise. Training caused reductions in systolic, diastolic, and mean arterial resting blood pressure (of -4.9 ± 6.3 mmHg, P = 0.01; -2.6 ± 3.0 mmHg, P = 0.01; and -2.6 ± 2.3 mmHg, P = 0.001 respectively; mean ± s). These were accompanied by changes in muscle activity, taken as electromyographic activity to reach a given lactate concentration (from 114 ± 22 to 131 ± 27 mV and from 136 ± 25 to 155 ± 34 mV for 3 and 4 mmol · L(-1) respectively. Training intensity expressed relative to peak lactate was correlated with reduced resting systolic and mean arterial blood pressure. Training caused significant shifts in lactate accumulation, and reductions in resting blood pressure are strongly related to training intensity, when expressed relative to pre-training peak lactate. This suggests that higher levels of local muscle anaerobiosis may promote the training-induced reductions in resting blood pressure.
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The isometric wall squat could be utilised in home-based training aimed at reducing resting blood pressure, but first its suitability must be established. The aim of this study was to determine a method of adjusting wall squat intensity... more
The isometric wall squat could be utilised in home-based training aimed at reducing resting blood pressure, but first its suitability must be established. The aim of this study was to determine a method of adjusting wall squat intensity and explore the cardiovascular responses. Twenty-three participants performed one 2 minute wall squat on 15 separate occasions. During the first ten visits, ten different knee joint angles were randomly completed from 135° to 90° in 5° increments; five random angles were repeated in subsequent visits. Heart rate and blood pressure (systolic, diastolic and mean arterial pressure) were measured. The heart rate and blood pressure parameters produced significant inverse relationships with joint angle (r at least -0.80; P < 0.05), demonstrating that wall squat intensity can be adjusted by manipulating knee joint angle. Furthermore, the wall squat elicited similar cardiovascular responses to other isometric exercise modes that have reduced resting blood pressure (135° heart rate: 76 ± 10 beats ∙ min(-1); systolic: 134 ± 14 mmHg; diastolic: 76 ± 6 mmHg and 90° heart rate: 119 ± 20 beats ∙ min(-1); systolic: 196 ± 18 mmHg; diastolic: 112 ± 13 mmHg). The wall squat may have a useful role to play in isometric training aimed at reducing resting blood pressure.
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Research Interests: Rhythm, Prediction, Energy Metabolism, Sport, Sports, and 25 moreHumans, Bicycling, Male, Human Performance, Regression Analysis, Heart rate, Soils, Sol, Physical Fitness, Rythme, Adult, Body Mass, Sports Sciences, Curriculum and Pedagogy, Hill Climbing, APTITUDE TEST, Stepwise Regression, Lactic Acid, *Physical Exertion, Exercise Test, Oxygen Consumption, Predictive value of tests, Wingate Test, Power Output, and prediction equation
The Rotor (ROT) is a cycle crank configuration that allows the pedals to move independently in an attempt to eliminate the “dead spots”, where torque output is minimal. Delta efficiency has been found to be significantly improved during... more
The Rotor (ROT) is a cycle crank configuration that allows the pedals to move independently in an attempt to eliminate the “dead spots”, where torque output is minimal. Delta efficiency has been found to be significantly improved during an incremental test when using ROT in a group of untrained cyclists (Santalla et al., 2002: Medicine and Science in Sports and Exercise, 34, 1854-1858). However, no study has investigated whether ROT affects cycling performance directly. Therefore, the purpose of this study was to investigate the effect of ...
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The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power... more
The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power output. Each participant completed multiple trials at power outputs ranging from 50 to 450 W. The work stages recorded were 60 s in duration and were repeated three times. Participants also completed a single trial on a cycle ergometer designed to assess bilateral contributions to work output (Lode Excaliber Sport PFM). The power output during the trials was significantly different between all three systems, (p < 0.01) 231.2 +/- 114.2 W, 233.0 +/- 112.4 W, 227.8 +/- 108.8 W for the Monark, SRM and Ergomopro system, respectively. When the bilateral contributions were factored into the analysis, there were no significant differences between the powermeters (p = 0.58). The reliability of the Ergomopro system (CV%) was 2.31 % (95 % CI 2.13 - 2.52 %) compared to 1.59 % (95 % CI 1.47 to 1.74 %) for the Monark, and 1.37 % (95 % CI 1.26 - 1.50 %) for the SRM powermeter. These results indicate that the Ergomopro system has acceptable accuracy under these conditions. However, based on the reliability data, the increased variability of the Ergomopro system and bilateral balance issues have to be considered when using this device.
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Research Interests: Engineering and Education
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This study examined the therapeutic effects of an inert placebo gel on experimentally induced muscle pain in a sports therapy setting. It aimed to investigate the degree to which conditioned analgesia, coupled with an expectation of... more
This study examined the therapeutic effects of an inert placebo gel on experimentally induced muscle pain in a sports therapy setting. It aimed to investigate the degree to which conditioned analgesia, coupled with an expectation of intervention, was a factor in subsequent analgesia. Participants were sixteen male and eight female sports therapy students at a UK University. With institutional ethics board approval and following informed consent procedures, each was exposed to pain stimulus in the lower leg in five conditions, ie, conditioning, prebaseline, experimental (two placebo gel applications), and postbaseline. In conditioning trials, participants identified a level of pain stimulus equivalent to a perceived pain rating of 6/10. An inert placebo gel was then applied to the site with the explicit instruction that it was an analgesic. Participants were re-exposed to the pain stimulus, the level of which, without their knowledge, had been decreased, creating the impression of an...
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The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21... more
The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg) performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT) and indoor laboratory trials (ILT) using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001). The coefficient of variation (CV) for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N), mean force (147.2 ± 24.7N), peak p...
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The placebo effect, a positive outcome resulting from the belief that a beneficial treatment has been received, is widely acknowledged but little understood. It has been suggested that placebo responsiveness, the degree to which an... more
The placebo effect, a positive outcome resulting from the belief that a beneficial treatment has been received, is widely acknowledged but little understood. It has been suggested that placebo responsiveness, the degree to which an individual will respond to a placebo, might vary in the population. The study aimed to identify placebo-responsive participants from a previously published paper that examined the effects of caffeine and placebos on cycling performance. A quantitative model of placebo responsiveness was defined. 14 male participants were subsequently classified as either placebo responsive or non-responsive. Interviews were conducted to corroborate these classifications. Secondary quantitative analyses of performance data were conducted to identify further placebo responses. Finally, the five factor model of personality was used to explore relationships between personality and placebo responsiveness. Overall, 5 of 14 participants were classified as placebo responsive. Per...
Research Interests: Mechanical Engineering, Bioinformatics, Personality, Life Sciences, Placebo Effect, and 13 moreQuantitative analysis, Biomedical Research, Qualitative, Text, Oxygen Uptake, Exercise, Five Factor Model, Quantitative Analysis, Double Blind, Medicine and Science In Sports and Exercise, Experimental Data, Sports Science, and Confidence Interval
The aim of this study was to evaluate the impact of a novel crank system on laboratory time-trial cycling performance. The Rotor system makes each pedal independent from the other so that the cranks are no longer fixed at 180°. Twelve... more
The aim of this study was to evaluate the impact of a novel crank system on laboratory time-trial cycling performance. The Rotor system makes each pedal independent from the other so that the cranks are no longer fixed at 180°. Twelve male competitive but non-elite cyclists (mean ± s: 35 ± 7 yr, Wmax = 363 ± 38 W, VO2peak = 4.5 ± 0.3 L·min(-1)) completed 6-weeks of their normal training using either a conventional (CON) or the novel Rotor (ROT) pedal system. All participants then completed two 40.23-km time-trials on an air-braked ergometer, one using CON and one using ROT. Mean performance speeds were not different between trials (CON = 41.7 km·h(-1) vs. ROT = 41.6 km·h(-1), P > 0.05). Indeed, the pedal system used during the time-trials had no impact on any of the measured variables (power output, cadence, heart rate, VO2, RER, gross efficiency). Furthermore, the ANOVA identified no significant interaction effect between main effects (Time-trial crank system*Training crank syst...
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To assess the effect of dietary manipulation on gross efficiency (GE), 15 trained male cyclists completed 3 × 2 h tests at submaximal exercise intensity (60 % Maximal Minute Power). Using a randomized, crossover design participants... more
To assess the effect of dietary manipulation on
gross efficiency (GE), 15 trained male cyclists
completed 3 × 2 h tests at submaximal exercise
intensity (60 % Maximal Minute Power). Using a
randomized, crossover design participants consumed
an isoenergetic diet (~4 000 kcal.day -1 ) in
the 3 days preceding each test, that was either
high in carbohydrate (HighCHO, [70 % of the
total energy derived from carbohydrate, 20 % fat,
10 % protein]), low in carbohydrate (LowCHO,
[70 % fat, 20 % carbohydrate, 10 % protein]) or
contained a moderate amount of carbohydrate
(ModCHO, [45 % carbohydrate, 45 % fat, 10 % protein]).
GE along with blood lactate and glucose were assessed every 30 min, and heart rate was measured at 5 s intervals throughout. Mean GE was significantly greater following the HighCHO
than the ModCHO diet (HighCHO = 20.4 % ± 0.1 %,
ModCHO = 19.6 ± 0.2 %; P < 0.001). Additionally,
HighCHO GE was significantly greater after
25 min (P = 0.015) and 85 min (P = 0.021) than in
the LowCHO condition. Heart rate responses in
the HighCHO condition were significantly lower
than during the LowCHO tests (P = 0.005). Diet
had no effect on blood glucose or lactate (P > 0.05).
This study suggests that before the measurement
of gross efficiency, participants’ diet should be
controlled and monitored to ensure the validity
of the results obtained.
gross efficiency (GE), 15 trained male cyclists
completed 3 × 2 h tests at submaximal exercise
intensity (60 % Maximal Minute Power). Using a
randomized, crossover design participants consumed
an isoenergetic diet (~4 000 kcal.day -1 ) in
the 3 days preceding each test, that was either
high in carbohydrate (HighCHO, [70 % of the
total energy derived from carbohydrate, 20 % fat,
10 % protein]), low in carbohydrate (LowCHO,
[70 % fat, 20 % carbohydrate, 10 % protein]) or
contained a moderate amount of carbohydrate
(ModCHO, [45 % carbohydrate, 45 % fat, 10 % protein]).
GE along with blood lactate and glucose were assessed every 30 min, and heart rate was measured at 5 s intervals throughout. Mean GE was significantly greater following the HighCHO
than the ModCHO diet (HighCHO = 20.4 % ± 0.1 %,
ModCHO = 19.6 ± 0.2 %; P < 0.001). Additionally,
HighCHO GE was significantly greater after
25 min (P = 0.015) and 85 min (P = 0.021) than in
the LowCHO condition. Heart rate responses in
the HighCHO condition were significantly lower
than during the LowCHO tests (P = 0.005). Diet
had no effect on blood glucose or lactate (P > 0.05).
This study suggests that before the measurement
of gross efficiency, participants’ diet should be
controlled and monitored to ensure the validity
of the results obtained.
Research Interests:
The purpose of this study was to determine the reproducibility of limb power outputs and cardiopulmonary responses, to incremental whole-body exercise using a novel swimming training machine. 8 swimmers with a mean age of 23.7 ± 4.6... more
The purpose of this study was to determine the reproducibility of limb power outputs and cardiopulmonary responses, to incremental whole-body exercise using a novel swimming training machine. 8 swimmers with a mean age of 23.7 ± 4.6 (yrs), stature 1.77 ± 0.13 (m) and body mass of 74.7 ± 2.8 (kg) gave informed consent and participated in repeat exercise testing on the machine. All subjects performed 2 incremental exercise tests to exhaustion using front crawl movements. From these tests peak oxygen consumption (VO(₂peak)), peak heart rate (HR(peak)), peak power output (W (peak)) and individual limb power outputs were determined. Results showed there were no significant differences between test 1 and 2 for any variable at exhaustion, and the CV% ranged from 2.8 to 3.4%. The pooled mean values were; VO(₂peak) 3.7 ± 0.65 L.min⁻¹, HR (peak) 178.7 ± 6.6 b.min⁻¹ and W (peak) 349.7 ± 16.5 W. The mean contributions to the total power output from the legs and arms were (37.3 ± 4.1% and 62.7 ±...
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The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power... more
The aim of this investigation was to assess the validity and reliability of the Ergomopro powermeter. Nine participants completed trials on a Monark ergometer fitted with Ergomopro and SRM powermeters simultaneously recording power output. Each participant completed multiple trials at power outputs ranging from 50 to 450 W. The work stages recorded were 60 s in duration and were repeated three times. Participants also completed a single trial on a cycle ergometer designed to assess bilateral contributions to work output (Lode Excaliber Sport PFM). The power output during the trials was significantly different between all three systems, (p < 0.01) 231.2 +/- 114.2 W, 233.0 +/- 112.4 W, 227.8 +/- 108.8 W for the Monark, SRM and Ergomopro system, respectively. When the bilateral contributions were factored into the analysis, there were no significant differences between the powermeters (p = 0.58). The reliability of the Ergomopro system (CV%) was 2.31 % (95 % CI 2.13 - 2.52 %) compar...
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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... 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 &lt; 0.001). Ratio limits of agreement between SRM and Kingcycle for OBLA showed a bias (P &lt; 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.
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Research Interests:
Although differences in daily activity levels have been assessed in cross-sectional walk-to-school studies, no one has assessed differences in body composition and dietary energy intake at the same time. In this study of 239 primary... more
Although differences in daily activity levels have been assessed in cross-sectional
walk-to-school studies, no one has assessed differences in body composition and
dietary energy intake at the same time. In this study of 239 primary school children,
there were no significant differences in daily activity levels, body composition, or
estimated dietary energy intake between those who walk to school (WALK) and
those who travel by car (CAR; p < .05). WALK children were more active between
8 a.m. and 9 a.m. and 3 p.m. and 4 p.m. than CAR children (p < .05). In addition,
there were no significant differences in the main analysis when participants were
subgrouped by gender and age.
walk-to-school studies, no one has assessed differences in body composition and
dietary energy intake at the same time. In this study of 239 primary school children,
there were no significant differences in daily activity levels, body composition, or
estimated dietary energy intake between those who walk to school (WALK) and
those who travel by car (CAR; p < .05). WALK children were more active between
8 a.m. and 9 a.m. and 3 p.m. and 4 p.m. than CAR children (p < .05). In addition,
there were no significant differences in the main analysis when participants were
subgrouped by gender and age.
Research Interests:
There are no previous reports of energy expenditure and perceived effort during brisk-walking and running at speeds self-selected by young children. Fifty four participants (age 8–11 years old) performed 1500 m of brisk-walking and... more
There are no previous reports of energy expenditure and perceived effort during brisk-walking and running at speeds self-selected by young children. Fifty four participants (age 8–11 years old) performed 1500 m of brisk-walking and running
in a marked school playground, and were given simple instructions to either ‘walk quickly’ or to ‘jog’. During the running the children achieved higher mean speeds
and a greater total energy expenditure (p < .001). However, there was no difference in the perceived effort between the two activities (p > .05). These findings suggest that under certain conditions children find it just as easy to run as they do to walk
briskly, even though the speed and energy expenditure is significantly higher.
in a marked school playground, and were given simple instructions to either ‘walk quickly’ or to ‘jog’. During the running the children achieved higher mean speeds
and a greater total energy expenditure (p < .001). However, there was no difference in the perceived effort between the two activities (p > .05). These findings suggest that under certain conditions children find it just as easy to run as they do to walk
briskly, even though the speed and energy expenditure is significantly higher.
Research Interests:
ABSTRACT There are limited data available on the injury occurrence associated with training in high-risk occupations. The aim of this investigation was to assess the injuries sustained during police training conducted by the Staff Safety... more
ABSTRACT There are limited data available on the injury occurrence associated with training in high-risk occupations. The aim of this investigation was to assess the injuries sustained during police training conducted by the Staff Safety Training Unit (SSTU), at Kent Police (Maidstone, Kent).
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Research Interests: Kinetics, Competition, Probability, Energy Metabolism, Sport, and 17 moreMedicine Science, Humans, Bicycling, Female, Male, Confidence intervals, Adult, Analysis of Variance, Physical Exercise, Medicine and Science In Sports and Exercise, Lactic Acid, *Physical Exertion, Exercise Test, Oxygen Consumption, Cohort Studies, Physical Endurance, and Anaerobic Threshold
Research Interests: Medicine Science, Humans, Blood sampling, Temperature, Coefficient of Variation, and 11 moreObserver Variation, Rest, Room Temperature, Time Factors, Reproducibility of Results, Bias (Epidemiology), Medicine and Science In Sports and Exercise, Lactic Acid, *Physical Exertion, Equipment Design, and Limits of Agreement
Research Interests:
The purpose of this study was (a) to assess lactate accumulation during isometric exercise, and to quantify the shifts in accumulation following isometric training; and (b) to relate any training-induced changes in lactate accumulation to... more
The purpose of this study was (a) to assess lactate accumulation during isometric exercise, and to quantify the shifts in accumulation following isometric training; and (b) to relate any training-induced changes in lactate accumulation to reductions in resting blood pressure. Eleven male participants undertook isometric training for a 4-week period using bilateral-leg exercise. Training caused reductions in systolic, diastolic, and mean arterial resting blood pressure (of -4.9 ± 6.3 mmHg, P = 0.01; -2.6 ± 3.0 mmHg, P = 0.01; and -2.6 ± 2.3 mmHg, P = 0.001 respectively; mean ± s). These were accompanied by changes in muscle activity, taken as electromyographic activity to reach a given lactate concentration (from 114 ± 22 to 131 ± 27 mV and from 136 ± 25 to 155 ± 34 mV for 3 and 4 mmol · L(-1) respectively. Training intensity expressed relative to peak lactate was correlated with reduced resting systolic and mean arterial blood pressure. Training caused significant shifts in lactate accumulation, and reductions in resting blood pressure are strongly related to training intensity, when expressed relative to pre-training peak lactate. This suggests that higher levels of local muscle anaerobiosis may promote the training-induced reductions in resting blood pressure.
Research Interests:
Currently, it is not possible to prescribe isometric exercise at an intensity that corresponds to given heart rates or systolic blood pressures. This might be useful in optimizing the effects of isometric exercise training. Therefore, the... more
Currently, it is not possible to prescribe isometric exercise at an intensity that corresponds to given heart rates or systolic blood pressures. This might be useful in optimizing the effects of isometric exercise training. Therefore, the aim of this study was to explore the relationships between isometric exercise intensity and both heart rate and systolic blood pressure during repeated incremental isometric exercise tests. Fifteen participants performed seated isometric double-leg knee extension, during which maximum voluntary contraction (MVC) was assessed, using an isokinetic dynamometer. From this, a corresponding peak electromyographic activity (EMG(peak)) was determined. Subsequently, participants performed two incremental isometric exercise tests (at least 48 h apart) at 10, 15, 20, 25, and 30% EMG(peak), during which steady-state heart rate and systolic blood pressure were recorded. In all participants, there were linear relationships between %EMG(peak) and heart rate (r at least 0.91; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and between %EMG(peak) and systolic blood pressure (r at least 0.92; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Also, when repeated tests were compared, there were no differences in the slopes (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.50) or elevations (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.10) for either of the relationships. Therefore, these linear relationships could be used to identify isometric exercise training intensities that correspond to precise heart rates or systolic blood pressures. Training performed in this way might provide greater insight into the underlying mechanisms for the cardiovascular adaptations that are known to occur as a result.
Research Interests: Humans, Blood Pressure, Male, Heart rate, Exercise, and 14 moreElectromyography, Steady state, Great Britain, Adult, Sports Sciences, Leg, Curriculum and Pedagogy, Muscle contraction, Surface Electromyography, *Physical Exertion, Exercise Test, Knee Extension, Systolic blood pressure, and Maximum Voluntary Contraction
There is a paucity of research on devices suitable for home-based isometric exercise. Our aim was to compare cardiovascular responses to isometric exercise using novel and established methods. Ten individuals (age 34.0 +/- 8.5 years, mass... more
There is a paucity of research on devices suitable for home-based isometric exercise. Our aim was to compare cardiovascular responses to isometric exercise using novel and established methods. Ten individuals (age 34.0 +/- 8.5 years, mass 68.2 +/- 10.4 kg, height 1.72 +/- 0.09 m; mean +/- s) performed three different isometric exercise protocols with 48 h between each. Each protocol involved four repeated exercise bouts of 2 min at 30% maximum voluntary contraction force using alternate legs (transducer), alternate arms (transducer), or alternate arms (novel device). Systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and heart rate were measured every 30 s. The highest (peak) values during each 2 min bout of exercise were recorded (peak systolic blood pressure, peak diastolic blood pressure, peak mean arterial blood pressure and peak heart rate). At the end of each 2 min exercise bout, the participants rated their perceived discomfort using Borg&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s CR-10 scale. There was a statistically significant difference in peak systolic blood pressure between isometric arm flexion using the force transducer and the novel device [158.1 +/- 10.8 vs. 149.1 +/- 13.9 mmHg (mean +/- s); P = 0.02]. Further analysis showed that peak systolic blood pressure was on average 9 mmHg higher using the force transducer with limits of agreement of - 15.97 to 33.97 mmHg. Analysis of the peak diastolic blood pressure, peak mean arterial blood pressure, peak heart rate and CR-10 data revealed no statistically significant differences between the three protocols. These results suggest that this novel, home-based method elicited similar cardiovascular responses during isometric exercise to those of established laboratory-based methods. However, the lower peak systolic blood pressure using the modified scales warrants further investigation before this method is used widely in the home.
Research Interests: Skeletal muscle biology, Self Care, Exercise therapy, Sport, Sports, and 22 moreHumans, Hemodynamics, Blood Pressure, Perceived Exertion, Female, Male, Statistical Significance, Arm, Heart rate, Exercise, Patient Satisfaction, Rest, Adult, Sports Sciences, Leg, Curriculum and Pedagogy, Isometric Exercise, Systolic blood pressure, Isometric Contraction, Maximum Voluntary Contraction, Diastolic Blood Pressure, and Limits of Agreement
There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of approximately 60 s duration. To address this, eight trained cyclists... more
There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of approximately 60 s duration. To address this, eight trained cyclists performed a 1 km time-trial on an electronically braked cycle ergometer under three conditions: after ingestion of 5 mg x kg-1 caffeine, after ingestion of a placebo, or a control condition. The three time-trials were performed in a randomized order and performance time, mean speed, mean power and peak power were determined. Caffeine ingestion resulted in improved 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). This change represented a 3.1% (95% confidence interval: 0.7-5.6) improvement compared with the placebo condition. Mean speed was also higher in the caffeine than placebo and control conditions (caffeine vs. placebo vs. control: 50.7 +/- 1.4 vs. 49.1 +/- 1.5 vs. 49.2 +/- 1.7 km x h-1; P = 0.0005). Mean power increased after caffeine ingestion (caffeine vs. placebo vs. control: 523 +/- 43 vs. 505 +/- 46 vs. 504 +/- 38 W; P = 0.007). Peak power also increased from 864 +/- 107 W (placebo) and 830 +/- 87 W (control) to 940 +/- 83 W after caffeine ingestion (P = 0.027). These results provide support for previous research that found improved performance after caffeine ingestion during short-duration high-intensity exercise. The magnitude of the improvements observed in our study could be due to our use of sport-specific ergometry, a tablet form and trained participants.
Research Interests:
Research Interests: Cardiovascular disease, Sports, Lipids, Apolipoproteins, Humans, and 24 moreWalking, Female, Male, Statistical Significance, Heart rate, Exercise, Apolipoprotein E, LDL-cholesterol, Physical Fitness, Aged, Middle Aged, Adult, Time Factors, Sports Sciences, Curriculum and Pedagogy, High Density Lipoprotein, Physical Exercise, Physical Training, Fibrinolysis, Blood Lipids, Low Density Lipoprotein (LDL), Total Cholesterol, Control Group, and Low density lipoprotein cholesterol
Research Interests: Rhythm, Prediction, Energy Metabolism, Sport, Sports, and 25 moreHumans, Bicycling, Male, Human Performance, Regression Analysis, Heart rate, Soils, Sol, Physical Fitness, Rythme, Adult, Body Mass, Sports Sciences, Curriculum and Pedagogy, Hill Climbing, APTITUDE TEST, Stepwise Regression, Lactic Acid, *Physical Exertion, Exercise Test, Oxygen Consumption, Predictive value of tests, Wingate Test, Power Output, and prediction equation
The isometric wall squat could be utilised in home-based training aimed at reducing resting blood pressure, but first its suitability must be established. The aim of this study was to determine a method of adjusting wall squat intensity... more
The isometric wall squat could be utilised in home-based training aimed at reducing resting blood pressure, but first its suitability must be established. The aim of this study was to determine a method of adjusting wall squat intensity and explore the cardiovascular responses. Twenty-three participants performed one 2 minute wall squat on 15 separate occasions. During the first ten visits, ten different knee joint angles were randomly completed from 135° to 90° in 5° increments; five random angles were repeated in subsequent visits. Heart rate and blood pressure (systolic, diastolic and mean arterial pressure) were measured. The heart rate and blood pressure parameters produced significant inverse relationships with joint angle (r at least -0.80; P &amp;amp;amp;amp;amp;amp;lt; 0.05), demonstrating that wall squat intensity can be adjusted by manipulating knee joint angle. Furthermore, the wall squat elicited similar cardiovascular responses to other isometric exercise modes that have reduced resting blood pressure (135° heart rate: 76 ± 10 beats ∙ min(-1); systolic: 134 ± 14 mmHg; diastolic: 76 ± 6 mmHg and 90° heart rate: 119 ± 20 beats ∙ min(-1); systolic: 196 ± 18 mmHg; diastolic: 112 ± 13 mmHg). The wall squat may have a useful role to play in isometric training aimed at reducing resting blood pressure.
Research Interests:
No previous studies have examined the effects of isometric training intensity upon resting blood pressure (BP). The aims of this study were (a) to compare the effects of leg isometric training, performed at two intensities, upon resting... more
No previous studies have examined the effects of isometric training intensity upon resting blood pressure (BP). The aims of this study were (a) to compare the effects of leg isometric training, performed at two intensities, upon resting systolic-SBP, diastolic-DBP and mean arterial-MAP BP; and (b) to examine selected cardiovascular variables, in an attempt to explain any changes in resting BP following training. Thirty-three participants were randomly allocated to either control, high- (HI) or low-intensity (LI) training for 8 weeks. Participants performed 4 x 2 min exercise bouts 3x weekly. Resting BP was measured at baseline, 4-weeks and post-training. SBP, DBP and MAP fell significantly in both groups after training. Changes were -5.2 +/- 4.0, -2.6 +/- 2.9 and -2.5 +/- 2.2 mmHg [HI]; -3.7 +/- 3.7, -2.5 +/- 4.8 and -2.6 +/- 2.5 mmHg [LI] for SBP, DBP and MAP, respectively. There were no significant changes in BP at 4 weeks. No significant changes were observed in any of the other cardiovascular variables examined. These findings suggest that isometric training causes reductions in SBP, DBP and MAP at a range of exercise intensities, when it is performed over 8 weeks. Furthermore, it is possible to reduce resting BP using a much lower isometric exercise intensity than has previously been shown.
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... Diversity in the Decomposing Landscape 21 7 Hansen, RA (2000) Effects of habitat complexity ... Pande, YD and Berthet, P.(1975) Observations on the vertical distribution of soil ... E. and Scheu, S.(1994) Oribatid mite mediated... more
... Diversity in the Decomposing Landscape 21 7 Hansen, RA (2000) Effects of habitat complexity ... Pande, YD and Berthet, P.(1975) Observations on the vertical distribution of soil ... E. and Scheu, S.(1994) Oribatid mite mediated changes in litter decomposition: model experiments ...
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Controversy still exists in the literature as to whether cycling experience affects gross mechanical efficiency (GME). The aim of this study was to identify differences in efficiency between trained and untrained cyclists. Thirty-two... more
Controversy still exists in the literature as to whether cycling experience affects gross mechanical efficiency (GME). The aim of this study was to identify differences in efficiency between trained and untrained cyclists. Thirty-two participants, 16 trained (mean+/-SD: age, 33+/-4 y; height, 1.76+/-0.05 m; mass 75+/-10 kg; Wmax, 421+/-38 W; maximal oxygen uptake, 62.6+/-7.30 mL.kg(-1).min(-1)) and 16 untrained (22+/-3 y, 175+/-0.06 m, 76+/-10 kg, 292+/-34 W, 42.6+/-7.80 mL.kg(-1).min(-1)), performed two tests of cycling efficiency. One was at the relative workloads of 50% and 60% Wmax and the other was at a fixed workload of 150 W using an electrically braked cycle ergometer. Cadence was maintained at the cyclist&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s preferred rate throughout. All workloads lasted 10 min with data sampling in the final 3 min. GME was calculated from the gas data. GME was found to be significantly higher in the trained cyclists across all workloads (+1.4%; p=0.03). At workloads of 60% Wmax GME was significantly lower than work at 150 W (-0.8%; p=0.04), but not significantly different from 50% Wmax. These results show that differences do exist between trained and untrained cyclists, illustrating that training experience is a factor that warrants further investigation.
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Canadian Society for Exercise Physiology Position Stand: The Use of Instability to Train the Core in Athletic and Nonathletic Conditioning/Prise de position de la Société canadienne de physiologie de l'exercice: L'utilisation de... more
Canadian Society for Exercise Physiology Position Stand: The Use of Instability to Train the Core in Athletic and Nonathletic Conditioning/Prise de position de la Société canadienne de physiologie de l'exercice: L'utilisation de l'instabilité dans l'entrainement des muscles profonds lors de conditionnement physique de sportifs et de non-sportifs