A variação da acuidade visual durante esforços fisicos em atletas com baixa visão




This research work evaluated the response of the visual acuity in visually impaired athletes during a procedure of continued physical exercise. The evaluation was carried out in two days of testing. The subjects were six visually impaired, high performance runners athletes. The following were carried out during the first day: medical examination, anamnesis and questionnaire, and peak physical exertion test based on Roecker s (1998) procedure, using a treadmill. The second day was dedicated to the continued exertion test which consisted of three exertion levels lasting 15 minutes each, with 30-minute intervals between them. The results of the peak effort test were used as a delimiting factor for applied intensities. These were 60% of peak VE, VE threshold, and 90% of peak VE. Visual acuity was assessed before, during and afier each exertion level of the continued exertion procedure. The first visual assessment (before) was carried out under static conditions; the second visual assessment (during) was carried out under both dynamic and static conditions. During recovery (after) the visual assessment was carried out under static conditions. The visual test used was an adaptation of the Snellen optometers. At 60% exertion intensity the results showed a reduction of 44.5% under dynamic conditions and 33.4% under static conditions. At that level, at the end o{the 30-minutc resting period the visual acuity returned to the pre-exertion level. During the exertion performed at the ventilatory threshold, visual acuity showed a maximum reduction of 52.5% under dynamic conditions and 42.9% under static conditions. The rest interval between the 2nd and 3rd exertion stages showed the fastest recovery, reaching its peak at 25 minutes, above the pre-exertion result, and decreasing in the final evaluation. At the last intensity level, there was a 60% reduction under dynamic conditions and 52.5% under static conditions. Visual acuity during the last stage of exertion showed an intermediate recovery speed between the 1-st and 2nd stages and reached the highest degree of visual acuity of the entire test. The reduction in visual acuity during exertion was proportional to the exertion intensity the greater stimulation load, the greater reduction in visual capacity. Dynamic conditions accentuated the degradation in visual acuity during the proposed procedure. During the interval between exertions the visual scale was inversely proportional to the intensity of the exercise - the greater the physical stimulation, the greater the degree of recovery. Visual behavior was influenced by learning and by physiological factors; therefore, the first level showed the worst results due to little experience, the second level showed the best results due to a qualitative improvement in vision and in the third stage there was a reduction in visual performance d1..le to the high intensity of stress undergone


deficientes visuais exercicios fisicos - aspectos fisiologicos atletas acuidade visual

Documentos Relacionados