Recovery From Unaccustomed Strenuous Exercise In Young And Older Endurance-trained Adults

Abstract

There is a well-conceived notion that rate of recovery from strenuous exercise gets slower with advancing age. It is not clear whether older adults who exercise habitually and are apparently healthy demonstrate slower rates of recovery from unaccustomed eccentric exercise. PURPOSE: The aim of the present study was to determine if older adults who are physically active demonstrate slower rates of recovery from unaccustomed strenuous eccentric exercise compared with younger peers. METHODS: A total of 39 apparently healthy men and women were studied; young sedentary (n=10, 28±2 years), young endurance-trained (n=15, 27±2 years), and older endurance-trained (n=14, 58±2 years) groups. Subjects performed 45 min (15 min x 3 times with 5 min resting periods) of downhill running (at -16% gradient) at a speed corresponding with 65% of their maximal oxygen consumption. Visual analog pain scale, isometric muscular strength, joint range of motion (ROM), and serum myoglobin concentration were measured at baseline as well as 24h, 48h, and 72h after the downhill running protocol. RESULTS: Compared with baseline, pain scores of each muscle group were greater at 24h, 48h, and 72h in all 3 groups (p<0.05). Isometric muscular strengths decreased following downhill running (p<0.05), but the pattern of this response and recovery did not differ among the three groups. The ROM for hip extension decreased after downhill running (p<0.05), with the most pronounced decline seen in the young sedentary group. ROM gradually increased to baseline levels in all 3 groups. Serum myoglobin concentrations increased at 24h and returned to baseline values at 48h in both the young and older trained groups. CONCLUSION: The present findings are not consistent with the prevailing notion that older trained adults have a slower rate of recovery from strenuous exercise compared with young adults.