The acute effects of aerobic and anaerobic exercises on respiratory muscle strength were examined in 24male subjects using the maximal inspiratory pressure (MIP) measurement in four different trials. The trial 1 was initial level of MIP and did not involve acute exercise. The trial 2 (aerobic exercise), trial 3 (anaerobic exercise for lower extremities), and trial 4 (anaerobic exercise for upper extremities)involved acute exercises before MIP measurement. Repeated measures one way analysis of variance test and Bonferroni correction were used for statistical analysis. Significant decreases in the MIP were found between the trial 1 and the other trials (p<0.05). Percent change of the trial 2, trial 3, and trial 4 were by-9.17%, -15.18% and -22.87% respectively, from the trial 1. Percent change of the trial 2, trial 3, and trial 4 of the eight subjects who had higher MIP value were by -6.00% , - 7.40%, and -12.87 respectively, from trial 1. Percent change of the trial 2, trial 3, and trial 4 of another selected six subjects who had lesser MIP value were by -11.30%, -17.74%, and -26.10% respectively, from trial 1.These results show that the aerobic and anaerobic acute exercises negatively affect respiratory muscle strength. Nevertheless, it could be said that stronger respiratory muscles show lesser decrement in muscle strength.
