Améliorations cardio-respiratoires et métaboliques après un entraînement par exercices en créneaux

Effects of a wheelchair ergometer training programme on spinal cord-injured persons

STUDY DESIGN

Before and after investigation of the effects of a wheelchair ergometer Training programme.

OBJECTIVE

To investigate the effects of an original interval-training programme on work capacity and cardiorespiratory variables with spinal cord-injured persons (SCIP's) on a wheelchair-specific ergometer.

SETTING

BESANCON, FRANCE.

METHODS

Seven SCIP's (male) performed 45 min of wheelchair ergometry three times per week, for 6 weeks. Training effects on maximal dynamic performance and endurance capacity were studied by comparison of performance and cardiorespiratory responses observed during both a maximal progressive test (10 W/2 min) and the same training session performed before and after training.

RESULTS

Training induced significant improvements in maximal tolerated power (+19.6%), in peak oxygen consumption (VO2,+16%), and in oxygen pulse (O2p,+18.7%). At ventilatory threshold, significant improvements were also observed in power output (+63%), VO2VT(+ 34.1), ventilation VEVT(+ 37.1%), and V2pVT(+ 19.9% ). Heart rate and ventilation were significantly lower (-11 and -14.6%, respectively) after training at the same work rate, while VO2 was unchanged. Between the first and the last training session, the total physical work was improved by 24.7%, whereas heart rate was unchanged.

CONCLUSION

An interval-training programme individualised to each paraplegic subject using a wheelchair ergometer can significantly improve the fitness level and endurance capacity.

Endurance training in patients with chronic obstructive pulmonary disease: a comparison of high versus moderate intensity

PURPOSE

To create a maximum tolerated 45-minute aerobic training program for patients with chronic obstructive pulmonary disease (COPD) and to compare its outcomes with those of commonly prescribed moderate exercise.

DESIGN

Prospective, randomized trial.

SETTING

A work physiology laboratory.

PATIENTS AND METHODS

The maximum exercise intensities that 7 COPD patients could sustain for 45 minutes were determined on a bilevel exercise ergometer. The patients then exercised 45 minutes daily, 5 days a week for 6 weeks, working 2.03+/-0.4 kJ/kg per session. They were matched with 6 COPD patients who pushed an O2 cart for 45 minutes daily, 5 days a week for 6 weeks, working 1.44+/-.35 kJ/kg per session.

RESULTS

A 45 minute maximal regimen was established by alternating 1-minute peak exercise at peak VO2-levels with 4 minutes at the ventilatory anaerobic threshold or at 40% of peak VO2. Maximal bilevel training significantly decreased dyspnea at rest (p< or =.01) and the blood lactate level during submaximal exercise (p<.001), and increased peak VO2 and total physical work (p<.01), maximum inspiratory and expiratory pressures (p<.01), and grip and forearm strength and endurance (p<.01). The training also increased maximum voluntary ventilation while decreasing the ventilatory equivalent during exercise (p<.001). The O2 cart pushers significantly improved only on the 12-minute walk (p<.05).

CONCLUSIONS

A maximally intense anaerobic exercise program can be created for most COPD patients that can significantly improve both skeletal and respiratory muscle strength and endurance as well as dyspnea and physiologic parameters.

Implications of lower- and upper-limb training procedures in patients with chronic airway obstruction

In assessing the effectiveness of lower-limb and upper-limb nonspecific physical training, we have considered 3 objectives in this study: (1) determination of clinical and functional actual state in patients with chronic airway obstruction (CAO), before and after training; (2) determination of the tests, level of work, and duration of the session training as well as how to increase the training load throughout the training program; and (3) the "particular" upper-limb exercise training in patients with CAO. Many personal factors such as psychologic (personality, degree of patient motivation), alcohol and smoking habits, physical activity, malnutrition, as well as routine tests, at rest and maximal exercise, including the control of metabolic acidosis (lactate) and arterial blood gases (or at least of SaO2), should be considered. Exercise training has the potential to improve exercise tolerance in those who develop metabolic acidosis. The pattern of lactates during exercise represents a good criterion on the selection of patient's training. Two ergospirometric strategies, at high intensity exercise, established from the anaerobic threshold (AT) are described: (a) the above AT 45 min constant exercise (high work rate), at 60% of the difference between AT and maximum VO2 or 80% of the maximal tolerated power (MTP), and (b) the "45 min square-wave endurance exercise test" (SWEET), simulating an interval training session, established from the MTP and the AT. To the SWEET's base (% MTP from AT or aerobic training), a peak of 60 s at MTP (anaerobic training) is added every 5 min. While those 2 protocols, after 6 to 8 weeks of training, lactate and ventilation were lower for identical work rate. In addition, endurance (time in "a" and total physical work in "b") increased up to 60%. Further, maximal exercise ventilation and maximum VO2 increased after SWEET training. Roughly every 7 training sessions, a 10% to 15% reduction in heart rate (HR), during the training program, allows the patient to increase the work rate of the sessions. Evaluation of training the upper limb in patients with CAO requires measurements of MTP and maximum VO2. With the upper limb (wheelchair ergometer), Wmax, maximum VO2, and HR represent 30%, 65%, and 95%, respectively, of the lower limb (ergometer). Further, some expiratory and inspiratory accessory muscles show electromyographic fatigue at the MTP upper-limb level. This may contribute to the rationale for training respiratory muscles.(ABSTRACT TRUNCATED AT 400 WORDS)