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Biomedical subjects

N Webborn

Publications and source records attributed to N Webborn.

5 recordsLinked to original sources

Aerobic capacity and peak power output of elite quadriplegic games players.

BACKGROUND: Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity. OBJECTIVE: To gain physiological profiles of highly trained British quadriplegic athletes, and to examine the relation between aerobic and sprint capacity. METHODS: Eight male quadriplegic athletes performed an arm crank exercise using an ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. The sprint test consisted of three maximum-effort sprints of five seconds duration against a resistance of 2%, 3%, and 4% of body mass. The highest power output obtained was recorded (PPO). Peak oxygen consumption (V(O2peak)), peak heart rate (HR(peak)), and maximal power output (PO(aer)) were determined. RESULTS: Mean PO(aer) was 67.7 (16.2) W, mean V(O2peak) was 0.96 (0.17) litres/min, and HR(peak) was 134 (19) beats/min for the group. There was high variability among subjects. Peak power over the five second sprint for the group was 220 (62) W. There was a significant correlation between V(O2peak) (litres/min) and PO(aer) (W) (r = 0.74, p<0.05). CONCLUSIONS: These British quadriplegic athletes have relatively high aerobic fitness when compared with the available literature. Moreover, the anaerobic capacity of these athletes appeared to be relatively high compared with paraplegic participants.

Adult↗

Effects of two cooling strategies on thermoregulatory responses of tetraplegic athletes during repeated intermittent exercise in the heat.

Athletes with spinal cord injury (SCI), and in particular tetraplegia, have an increased risk of heat strain and consequently heat illness relative to able-bodied individuals. Strategies that reduce the heat strain during exercise in a hot environment may reduce the risk of heat illness. To test the hypotheses that precooling or cooling during intermittent sprint exercise in a heated environment would attenuate the rise in core temperature in tetraplegic athletes, eight male subjects with SCI (lesions C(5)-C(7); 2 incomplete lesions) undertook four heat stress trials (32.0 +/- 0.1 degrees C, 50 +/- 0.1% relative humidity). After assessment of baseline thermoregulatory responses at rest for 80 min, subjects performed three intermittent sprint protocols for 28 min. All trials were undertaken on an arm crank ergometer and involved a no-cooling control (Con), 20 min of precooling (Pre), or cooling during exercise (Dur). Trials were administered in a randomized order. After the intermittent sprint protocols, mean core temperature was higher during Con (37.3 +/- 0.3 degrees C) compared with Pre and Dur (36.5 +/- 0.6 degrees C and 37.0 +/- 0.5 degrees C, respectively; P < 0.01). Moreover, perceived exertion was lower during Pre (13 +/- 2; P < 0.01) and Dur (12 +/- 1; P < 0.01) compared with Con (14 +/- 2). These results suggest that both precooling and cooling during intermittent sprint exercise in the heat reduces thermal strain in tetraplegic athletes. The cooling strategies also appear to show reduced perceived exertion at equivalent time points, which may translate into improved functional capacity.

Adaptation, Physiological↗

Randomised controlled trial to examine the effects of a GP exercise referral programme in Hailsham, East Sussex, on modifiable coronary heart disease risk factors.

OBJECTIVE: To examine the effects of a GP exercise referral programme on modifiable coronary heart disease risk factors. DESIGN: Randomised controlled trial. A battery of validated measures were carried out at 0, 8, 16, 26, and 37 weeks. SETTING: Two community health centres and a leisure centre in Hailsham, East Sussex. SUBJECTS: 389 patients (smokers, hypertensive or overweight) were selected from medical records, screened for contraindications to exercise and 345 were invited into the study. Of 142 patients randomly allocated, 40 (41%) completed the study in the exercise group and 31 (69%) in the control group. Sixty (35%) invited smokers (48% of non-smokers), 71 (38%) invited hypertensive patients (45% of non-hypertensive patients), and 107 (45%) overweight patients (33% of non-overweight patients) were randomised. Of those randomised, 27 (45%) smokers, 52 (48%) overweight, and 43 (61%) hypertensive patients completed the study. INTERVENTION: The exercise group was offered 20, half price sessions over 10 weeks at a leisure centre. Patients engaged in moderate and vigorous aerobic type activity on various exercise machines, in a semi-supervised, informal environment. RESULTS: 87% of those referred used the prescription and 28% (high adherers)(45% of obese patients) did at least 15 sessions. The exercise group reduced sum of skinfolds by 8.1% (2.9 to 13.3, 95% confidence intervals) more than the control group, up to 16 weeks after baseline. High adherers reduced sum of skinfolds by 9.2% (0.9 to 17.5) more than the control group, up to 26 weeks. High adherers reduced systolic blood pressure by 7.2% (-0.7 to 14.9) (that is, 9 mm Hg) more than low adherers, up to 37 weeks. Non-smokers and obese patients attended more prescribed sessions than smokers and non-overweight patients. CONCLUSIONS: Reduction in sum of skinfolds was maintained up to 26 weeks, among high adherers compared with controls. Reduction in systolic blood pressure was evident up to 37 weeks among high adherers, but only in comparison with low adherers. Selection of appropriate referees and use of other strategies to improve exercise adherence will help to maximise the benefits from GP exercise prescription schemes.

Coronary Disease↗