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Purpose: Both constant and intermittent acute aerobic exercises have been found to decrease arterial stiffness. However, direct comparisons of these two types of exercise are sparse. It is not known which type of exercise has the greatest effect.Methods: We evaluated the haemodynamic responses in 15 males (age 48.5 ± 1.3 years; BMI 27.5 ± 0.8 kg m-2) following acute constant (CE) and intermittent cycling exercise (IE). Duration and heart rate were matched during both exercises (131.8 ± 3.2 bpm for CE and 132.0 ± 3.1 bpm for IE). Central and peripheral arterial stiffness was assessed through pulse wave velocity (PWV). Plasma concentrations of nitric oxide (NO), atrial natriuretic peptide (ANP), blood lactate, noradrenaline, and adrenaline were measured before and after each exercise.Results: Central (+ 1.8 ± 7.4 and - 6.5 ± 6.8% for CE and IE) and upper limb PWV (+ 2.7 ± 6.2 and - 8 ± 4.6% for CE and IE) were not significantly altered although a small decrease (small effect size) was observed after IE. However, lower limb PWV significantly decreased after exercises (- 7.3 ± 5.7 and - 15.9 ± 4% after CE and IE), with a larger effect after IE.Conclusions: Greater decrease in lower limb PWV occurred after IE despite greater heart rate. This may be due to the higher blood levels of lactate during IE, while NO, ANP, noradrenaline, and adrenaline levels remained not statistically different from CE. These results underlined the importance of lactate in triggering the post-exercise vascular response to exercise, as well as its regional characteristic. [ABSTRACT FROM AUTHOR]

Study design:Cross-over study.Objective:To determine the effect of strenuous wheelchair exercise on oxygen uptake ( ), muscle activity and propulsion cycle timing (including the push time and recovery time during one full arm cycle).Setting:Laboratory of Sport Sciences at the University of France-Comte in France.Methods:Two exercise bouts of 6-min duration were performed at a constant workload: (1) non-fatigable exercise (moderate workload) and (2) fatigable exercise (heavy workload). Measurement of , surface electromyographic activity (EMG) from shoulder muscles, and temporal parameters of wheelchair ergometer propulsion were collected from eight able-bodied men (26±4 years).Results:A progressive increase in associated with EMG alterations (P<0.05), and a decrease of the cycle and recovery time (P<0.05) during the heavy exercise. Whereas the push time remained constant, an increased muscle activation time (P<0.05) was found during heavy exercise.Conclusion:Observations during wheelchair ergometry indicate the development of fatigue and inefficient muscle coordination, which may contribute to deleterious stress distributions at the shoulder joint, increasing susceptibility to injury.Spinal Cord (2007) 45, 468–474; doi:10.1038/sj.sc.3101989; published online 24 October 2006 [ABSTRACT FROM AUTHOR]

Compares the effects of a rehabilitation program on the perceived exertion and the cardioventilatory responses during exercise in healthy people and paraplegics. Implication of rehabilitation exercise for the maximal tolerated power and peak oxygen uptake; Measurement of heart rate and perceived exertion and pain; Problems regarding the thermal regulation disorders of paraplegics.

BACKGROUND:: Various combinations of training intensity, duration and frequency are often proposed to people with spinal cord injuries in order to improve their fitness. However, no consensus about a specific training program has been reached for such a population. OBJECTIVE:: This study investigated the effects of a short interval training program specifically designed for patients with spinal cord injuries. METHODS:: Paraplegic men performed 30-min wheelchair ergometry three times per week, for 4 weeks. Maximal dynamic performance and endurance capacity were studied before and after the training program with an incremental test (10 W/2 min) until volitional fatigue and a constant work rate test, respectively. Cardiorespiratory responses were continuously studied during each of these tests. RESULTS:: Training induced significant improvement in maximal tolerated power (+27.9%), and in peak oxygen consumption (&Vdot;O2, +18.5%). After training the subjects were able to maintain the load applied during the constant test (total mechanical work +210.7%), for a significantly longer time. The heart rate, &Vdot;O2 and ventilation values observed when the volunteers ended their first constant load test were significantly higher (+10%, +10%, +40% respectively) than those obtained after a similar time period during the second constant load test which was performed after the training program. CONCLUSION:: After this short training period, with an appropriate combination of different types of training, duration, intensity and frequency exercises, we observed a significant improvement in the fitness level and endurance capacity of paraplegic subjects.Spinal Cord (2001) 39, 532–537. [ABSTRACT FROM AUTHOR]