Hypothesis: We examined whether increasing peak aerobic capacity for walking (VO2peak) by interval walking training (IWT) is closely linked with decreasing the indices of lifestyle-related diseases in middle-aged and older people.
Methods: For 4 months from April to September of 2005 or 2006, 246 males and 580 females (~65 yr) performed IWT consisting of ≥ 5 sets of fast walking at ≥ 70% VO2peak for 3 min followed by slow walking at ≤ 40% VO2peak for 3 min ≥ 4 days/wk. Before and after IWT, we measured VO2peak, body mass index (BMI), %body fat, arterial blood pressure, thigh muscle strength, and blood parameters. We analyzed 198 males and 468 females who had undergone all the measurements both before and after IWT. To examine the hypothesis, we divided the subjects equally into 3 groups according to their pre-training VO2peak: low, middle, and high groups for each gender.
Results: Before training, we found that thigh muscle strength and blood HDL-cholesterol concentration were lower while body weight, BMI, %body fat, arterial blood pressure, and blood glucose were higher in the low group than the high group (all, P<0.05). After training, although VO2peak and thigh muscle strength increased and body weight, BMI, %body fat, blood pressure, and blood glucose concentration decreased in all groups (all, P<0.05), the changes were greatest in the low group for both genders.
Conclusion: VO2peak at baseline and changes in response to training were closely linked with indices of lifestyle-related diseases.