Cardioprotective Benefits Associated With Routine Physical Activity In Middle Aged Population

Abstract

PURPOSE: It is well known that routine intensive physical activity (PA) will result in positive cardiovascular adaptations. Similarly, it is known that aging will cause decrements in similar common measures of cardiovascular health. However, there is only limited data on the cardiovascular performance of an older, presumably healthy, physically active population who have remained active for decades. METHODS: Thirteen masters level swimmers (MS) and eight controls (IC) (54.3 ± 12.7yrs and 57.5 ± 7.9yrs; respectively) were asked to wear an ambulatory heart rate monitor (Actiheart) for seven consecutive days. Subjects were partitioned based upon self-reported long-term physical activity and asked to maintain their normal daily activities for the entirety of the data collection period. Heart rate was collected during waking hours (14.8 ± 3.2 hrs). All HR data was verified via accelerometer. To measure HRpeak and estimate cardiovascular fitness level, subjects completed a 1-mile timed walk. Independent two-sample t-tests were used for all comparisons, significance set at p<0.05. RESULTS: Mean daily HRmin and HRavg was lower in MS than IC (54 ± 5 vs 67 ± 8bpm, 72 ± 8bpm vs. 83 ± 9bpm; p<0.05, respectively) while mean daily HRmax was higher in MS (139 ± 18bpm vs. 131 ± 19bpm; p<0.05). Mean daily HRmax was higher than HRpeak during the 1-mile test for MS (139 ± 19 vs. 123 ± 20bpm; p<0.05) but not for IC (131 ± 18 vs. 135 ± 18; p = 0.69). CONCLUSIONS: Persistent participation in routine physical activity at any age appears to result in training induced changes consistent with improved cardiovascular health. Results from the present study, however, suggest that a 1 mile walk may not be an appropriate test for the physically active as it tends to underestimate maximum values for heart rate.