Effects of High-Intensity Interval Walking Training on Physical Fitness and Blood Pressure in Middle-Aged and Older People

Abstract

Although moderate-paced walking at about 6 km/h is thought to protect elderly persons against disability and age-related diseases, it may not suffice to increase peak aerobic capacity and other markers of fitness. This study compared the effects of moderate-intensity continuous walking training with those of high-intensity interval walking training on thigh muscle strength, peak aerobic capacity, and blood pressure. Participating in the 5-month study were 60 men and 186 women whose age averaged 63 years. One group used a pedometer to take at least 8000 steps daily for 4 or more days each week at about 50% of peak aerobic capacity, and another group—monitored by accelerometry—repeated 5 or more sets of 3-minute low-intensity walking at 40% of peak aerobic capacity, followed by 3 minutes of high-intensity walking above 70% of peak aerobic capacity, for 4 or more days per week. A control group did not engage in walking training and were asked to pursue a sedentary lifestyle. Targets were met by 46 nontraining subjects, 51 of those training continuously, and 42 of those doing high-intensity interval training. In those engaging in high-intensity interval training, isometric knee extension increased by 13%, isometric knee flexion by 17%, peak aerobic capacity for cycling by 8%, and peak aerobic capacity for walking by 9%. All these effects were significantly greater than those documented after moderate-intensity continuous walking training. Resting systolic blood pressure was reduced the most in those engaging in high-intensity interval walking training. Of 33 participants whose peak aerobic capacity for walking increased with interval walking, 25 had decreased systolic blood pressure.