TRAINING OF THE RESPIRATORY MUSCLES IN INDIVIDUALS WITH TETRAPLEGIA 233

Abstract

The purpose of this study was to evaluate whether training of the innervated respiratory muscles in people with a cervical spinal cord injury will improve the strength and endurance capacity of these muscles and the exercise performance in these people. Nine individuals with tetraplegia performed an endurance training of the inspiratory muscles, twice a day for 15 min. First, the subjects trained for 6 wk with no appreciable resistance (NR), after that they trained for 6 wk with a resistance (R) of 70% of their individual maximal endurance capacity of the inspiratory muscles. The training was evaluated using the following tests: 1) a lung function test, in which the vital capacity and the forced inspiratory and expiratory volumes over 1 sec were measured; 2) a ventilation test, in which the maximal inspiratory and expiratory mouth pressure (Pimax and Pemax) and the endurance pressure (Piendu) were measured; 3) a maximal arm-cranking exercise test. Both NR and R-training had no effect on the lung function parameters, in addition, NR had no effect on ventilation nor on exercise parameters. However, after R-training Piendu increased from 35.3 ± 11.2 mmHg to 46.2± 11.8 mmHg (p=0.01), representing the endurance capacity, whereas Pimax and Pemax, representing the strength, remained unchanged. R also increased the ratio between the Pimax and the Piendu from 58.3 ± 18.6% to 77.3 ± 23.3% (p=0.02). The oxygen uptake(˙VO2 peak) at maximal exercise improved from 0.87 ± 0.49 l·min-1 to 0.98 ± 0.44 l·min-1. The results of the study indicate that training of the respiratory muscles results in an enhanced endurance capacity of these muscles and a concomittant increase in exercise performance.