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Biomedical subjects

R Ramsbottom

Publications and source records attributed to R Ramsbottom.

12 recordsLinked to original sources
PubMed2001

Effect of training on accumulated oxygen deficit and shuttle run performance.

BACKGROUND: The purpose of the present study was to investigate changes in physiological, metabolic and performance parameters resulting from an intense 6 week training programme. METHODS: Sixteen volunteers were divided into a control (CN; 4 men and 2 women) and training group (TR; 6 men and 4 women). Laboratory measures included maximal aerobic power (VO2max), submaximal oxygen uptake (10.5 percent or 6 degrees treadmill inclination) and accumulated oxygen deficit (AOD). Performance was assessed during 20 metre shuttle run tests (PST, progressive shuttle run test; HIST, high intensity shuttle run test). RESULTS: TR improved their HIST performance (m) significantly compared with CN, identified by a significant "group-by-training" interaction (p<0.01). Similarly, AOD values improved more in TR compared with CN (p<0.01). There was a trend for TR to further reduce blood pH values after training compared with CN, although this decrease (approximately 0.05 units) did not attain statistical significance. The change in AOD was strongly correlated with the change in run time to exhaustion (r=0.76, p<0.01) and the change in estimated total work output (r=0.69, p<0.01) during 10.5 percent gradient running and modestly correlated with the change in HIST performance (r=0.49, p<0.05, assuming a directional test). CONCLUSIONS: The results of the present study suggest changes in the anaerobic capacity, determined as AOD, due to training may be reflected in corresponding changes in laboratory and field performance.

Adult↗
PubMed1997

Accumulated oxygen deficit and shuttle run performance in physically active men and women.

The aim of this study was to establish the validity of using shuttle run performance over 20 m to predict accumulated oxygen deficit. A new high-intensity shuttle run test (HIST) was devised, during which subjects ran to exhaustion at a speed equivalent to 120% of their performance attained during a progressive shuttle run test. The reliability of the new test was examined and found to be acceptable for 18 subjects who performed the test twice on separate days (r = 0.84, P < 0.01, study I). The discriminating ability of the new test was examined by comparing the distance covered by eight sprint- and eight endurance-trained athletes at 120% of their respective progressive shuttle run performances (615 +/- 111 vs 273 +/- 84 m, P < 0.01, study II). The strongest predictor of accumulated oxygen deficit for 27 subjects was found to be the geometric mean of the performances on the new test and on the progressive shuttle run test (r = 0.74, study III). The regression equation for this relationship was then used to estimate the accumulated oxygen deficit for a second group of 16 subjects (study IV). The correlation between the estimated and measured accumulated oxygen deficits was significant (r = 0.79, P < 0.01). The results from studies III and IV were therefore combined with the data from six new subjects to give a regression equation for predictive purposes based on 49 subjects.

Adult↗
PubMed1994

Accumulated oxygen deficit and short-distance running performance.

Recent studies have suggested that determining the accumulated oxygen deficit (AOD), in units of oxygen equivalents per kilogram body mass (ml O2 Eq.kg-1), during a short exhaustive run, may represent a non-invasive measure of anaerobic metabolism. However, there is little information either on the reproducibility of the laboratory determination or its relationship with human performance. The purpose of the present investigation was to determine the reproducibility of AOD during inclined treadmill running (study 1), and to examine its relationship with short-distance running performance (study 2). Twelve volunteers (11 males, 1 female) took part in study 1 and AOD was determined (relative exercise intensity approximately 120% VO2 max) on two separate occasions at a treadmill inclination of 10.5%; the laboratory-measured AOD values were 65.2 +/- 10.9 vs 66.3 +/- 12.5 ml O2 Eq.kg-1, respectively (r = 0.94, P < 0.01). A second subject group (10 males, 4 females) undertook study 2, which investigated AOD values and track times over 100, 400 and 800 m. The mean calculated AOD value was 66.1 +/- 12.0 ml O2 Eq.kg-1, and the average track times were 13.6 +/- 1.3, 60.9 +/- 6.8 and 138.8 +/- 18.5 s for the 100, 400 and 800 m, respectively. The r-values for the relationship between AOD and track time were -0.88, -0.82 (P < 0.01) and -0.61 (P < 0.05) for the 100, 400 and 800 m, respectively. The results of the present study suggest that the AOD (ml O2 Eq.kg-1) is a unique and reproducible physiological characteristic which is strongly correlated with sprint capacity.

Adult↗
PubMed1993

Maximal shuttle running over 40 m as a measure of anaerobic performance.

Over the last decade increasing interest has been shown in the measurement of anaerobic power and capacity in athletic men. These physiological characteristics have been determined predominantly using cycle ergometry and treadmill sprinting. The purpose of the present study was to examine the relationship between 40-m maximal shuttle run times and performance indices obtained during treadmill sprinting and cycle ergometry. Moderate correlations were found between 10-m split times (the time taken to cover the initial 10 m of the shuttle course) and treadmill peak power outputs (r = -0.67; P < 0.05). Similar relationships were also found between the fastest 40-m time and mean power outputs generated on both the treadmill and cycle ergometer (r = -0.67; P < 0.05) and (r = -0.75; P < 0.05) respectively. The correlations remained unchanged when the values were adjusted for body weight (W kg-1). The results of the present study suggest that maximal 40-m shuttle running ability may reflect anaerobic indices of power and capacity, determined using standard laboratory procedures.

Adult↗
PubMed1992

Modelling bivariate relationships when repeated measurements are recorded on more than one subject.

This paper examines the problems of modelling bivariate relationships when repeated observations are recorded for each subject. The statistical methods required to test for a common group model were introduced using an example from exercise physiology, where the oxygen cost of running at four different speeds was recorded for a group of 30 recreationally active males. When data for each subject were studied individually, both the plots and correlations suggested the relationship to be linear. Hence, the homogeneity of the subjects' regression lines was compared using the appropriate ANOVA test. The analysis revealed a significant difference in the slopes and intercepts of the lines, thus precluding the use of a single linear model to represent the group. If the subjects were divided into two groups according to the median maximum oxygen consumption (VO2max), a multivariate analysis of variance of the slope and intercept parameters helped to explain some of this heterogeneity (P less than 0.05). However, for physiological rather than statistical reasons, it was necessary to re-analyse the data without the fourth running speed. The revised analysis suggested that the subjects' lines would be better modelled with a common slope but separate intercepts. As before, by dividing the subjects into two groups according to the median VO2max score, a simple t-test indicated that differences in the subjects' intercept parameters were not significant (P = 0.08). Notwithstanding the relatively homogeneous nature of the 30 subjects in terms of VO2max, the statistical methods showed that differences in running economy are, to some extent, dependent on VO2max.

Adolescent↗
PubMed1992

Scaling physiological measurements for individuals of different body size.

This paper examines how selected physiological performance variables, such as maximal oxygen uptake, strength and power, might best be scaled for subject differences in body size. The apparent dilemma between using either ratio standards or a linear adjustment method to scale was investigated by considering how maximal oxygen uptake (l.min-1), peak and mean power output (W) might best be adjusted for differences in body mass (kg). A curvilinear power function model was shown to be theoretically, physiologically and empirically superior to the linear models. Based on the fitted power functions, the best method of scaling maximum oxygen uptake, peak and mean power output, required these variables to be divided by body mass, recorded in the units kg 2/3. Hence, the power function ratio standards (ml.kg-2/3.min-1) and (W.kg-2/3) were best able to describe a wide range of subjects in terms of their physiological capacity, i.e. their ability to utilise oxygen or record power maximally, independent of body size. The simple ratio standards (ml.kg-1.min-1) and (W.kg-1) were found to best describe the same subjects according to their performance capacities or ability to run which are highly dependent on body size. The appropriate model to explain the experimental design effects on such ratio standards was shown to be log-normal rather than normal. Simply by taking logarithms of the power function ratio standard, identical solutions for the design effects are obtained using either ANOVA or, by taking the unscaled physiological variable as the dependent variable and the body size variable as the covariate, ANCOVA methods.

Analysis of Variance↗
PubMed1992

Physiological and metabolic responses of men and women to a 5-km treadmill time trial.

Previous studies have reported strong correlations between 5-km performance times and maximal oxygen uptake (VO2 max) and also for running speeds equivalent to blood lactate concentrations of 4 mM. However, there is little information on the physiological responses of individuals during races over this distance. Therefore, the aim of the present study was to measure the physiological and metabolic responses of endurance trained male (n = 8) and female (n = 8) runners during a 5-km time trial using an instrumented treadmill. Performance times were 18.77 +/- 1.27 min for the men and 21.80 +/- 1.98 min for the women (P less than 0.01). The corresponding times on the athletics track were 17.68 +/- 0.39 min for the men (P less than 0.05) and 20.70 +/- 2.16 min for the women (N.S.). During the treadmill time trials, both the men and women were able to utilize approximately 90% VO2 max, 82% VE max, 98% HR max and produce similar concentrations of blood lactate. Although the physiological and metabolic responses of these endurance-trained men and women to 5-km treadmill running were similar, the faster running times recorded by the men in this study were the result of their higher VO2 max values.

Energy Metabolism↗
PubMed1989

Aerobic fitness and running performance of male and female recreational runners.

The purpose of the present study was to assess fitness and running performance in a group of recreational runners (men, n = 18; women, n = 13). 'Fitness' was determined on the basis of their physiological and metabolic responses during maximal and submaximal exercise. There were strong correlations between VO2 max and treadmill running speeds equivalent to blood lactate concentrations of 2 mmol l-1 (V-2 mM) or 4 mmol l-1 (V-4 mM), 'relative running economy' and 5 km times (r = -0.84), but modest and non-significant correlations between muscle fibre composition and running performance. The results of the submaximal exercise tests suggested that the female runners were as well trained as the male runners. However, the men still recorded faster 5 km times (19.20 +/- 1.97 min vs 20.97 +/- 1.70 min; P less than 0.05). Therefore the of the present study suggest that the faster performance times recorded by the men were best explained by their higher VO2 max values, rather than their training status per se.

Adult↗
PubMed1989

Training induced physiological and metabolic changes associated with improvements in running performance.

The purpose of the present study was to examine the relationship between improvements in running performance and some of the prominent physiological and metabolic adaptations to endurance exercise training. Twelve male undergraduates agreed to participate in this study (trial group), aged matched physical education students provided a control group. Running performance, assessed as a five km time trial, improved from 19.69 +/- 2.24 to 19.22 +/- 2.03 min in the trial group (P less than 0.01) after training. Maximal oxygen uptake values increased from 56.0 +/- 6.1 to 60.7 +/- 5.4 ml.kg-1.min-1, the running speed equivalent to a blood lactate reference concentration of 4 mmol.l-1 (V-4 mM) increased from 3.79 +/- 0.77 to 4.04 +/- 0.71 m.s-1, and the rate of oxygen consumption at 3.58 m.s-1 (running economy) increased from 43.3 +/- 3.2 to 45.0 +/- 3.4 ml.kg-1.min-1 (P less than 0.01). The control group did not show any significant changes. The improved five km times in the trial group were significantly correlated (r = -0.71; P less than 0.01) with changes in the running economy rather than changes in the VO2 max (r = -0.07; ns), or V-4 mM (r = -0.13; ns) suggesting the increased rate of oxygen utilization reflected a greater oxidative degradation of metabolic substrates together with a slower rate of lactate production.

Humans↗
PubMed1988

A progressive shuttle run test to estimate maximal oxygen uptake.

The purpose of the present study was to examine the validity of using a 20 m progressive shuttle run test to estimate maximal oxygen uptake. Running ability was described as the final level attained on the shuttle run test and as time on a 5 km run. Maximal oxygen uptake (VO2 max) was determined directly for seventy-four volunteers (36 men, 38 women) who also completed the shuttle run test. Maximal oxygen uptake values were 58.5 +/- 7.0 and 47.4 +/- 6.1 ml.kg-1.min-1 for the men and women respectively (mean +/- SD, P less than 0.01). The levels attained on the shuttle run test were 12.6 +/- 1.5 (men) and 9.6 +/- 1.8 (women; P less than 0.01). The correlation between VO2 max and shuttle level was 0.92. The correlation between VO2 max and the 5 km run was -0.94 and the correlation between both field tests was -0.96. The results of this study suggest that a progressive shuttle run test provides a valid estimate of VO2 max and indicates 5 km running potential in active men and women.

Adult↗
PubMed1987

Determinants of five kilometre running performance in active men and women.

Previous studies of elite endurance athletes have suggested that success in distance running is attributable to the possession of a high maximal oxygen uptake (VO2 max), the utilisation of a large fraction of the VO2 max and to running economy. The purpose of the present study was to examine the relationships between these physiological characteristics and running performance in active but not elite men and women. Maximal oxygen uptake values were 57.6 +/- 6.2 and 46.6 +/- 4.8 ml . kg.-1 min-1 for the men and women respectively (p less than 0.01). Running performance was assessed as a 5 km time trial and the men completed this distance in 19.77 +/- 2.27 min and the women in 24.44 +/- 3.19 min (p less than 0.01). Maximal oxygen uptake showed strong correlations (p less than 0.01) with running performance (men, r = -0.85; women, r = -0.80) but there was only a modest relationship between running economy and performance (men, r = 0.39; women, r = 0.34). The results of the present study suggest that the faster 5 km performance times recorded by the men were best explained by their higher VO2 max values.

Female↗