Tuesday, July 17, 2007

Walking - intervals win again!

Comment - once again, intervals give a more pronounced benefit and improvement in fitness than continuous "cardio".


Effects of High-Intensity Interval Walking Training on Physical Fitness and Blood Pressure in Middle-Aged and Older People
KEN-ICHI NEMOTO, MS; HIROKAZU GEN-NO, PHD; SHIZUE MASUKI, PHD; KAZUNOBU OKAZAKI, PHD; HIROSHI NOSE, MD, PHD




OBJECTIVE: To examine whether high-intensity interval walking training increased thigh muscle strength and peak aerobic capacity and reduced blood pressure more than moderate-intensity continuous walking training.

PARTICIPANTS AND METHODS: From May 18, 2004, to October 15, 2004 (5-month study period), 60 men and 186 women with a mean±SD age of 63±6 years were randomly divided into 3 groups: no walking training, moderate-intensity continuous walking training, and high-intensity interval walking training. Participants in the moderate-intensity continuous walking training group were instructed to walk at approximately 50% of their peak aerobic capacity for walking, using a pedometer to verify that they took 8000 steps or more per day for 4 or more days per week. Those in the high-intensity interval walking training group, who were monitored by accelerometry, were instructed to repeat 5 or more sets of 3-minute low-intensity walking at 40% of peak aerobic capacity for walking followed by a 3-minute high-intensity walking above 70% of peak aerobic capacity for walking per day for 4 or more days per week. Isometric knee extension and flexion forces, peak aerobic capacity for cycling, and peak aerobic capacity for walking were all measured both before and after training.

RESULTS: The targets were met by 9 of 25 men and 37 of 59 women in the no walking training group, by 8 of 16 men and 43 of 59 women in the moderate-intensity continuous walking training group, and by 11 of 19 men and 31 of 68 women in the high-intensity interval walking training group. In the high-intensity interval walking training group, 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, P<.001), all of which were significantly greater than the increases observed in the moderate-intensity continuous walking training group (all, P<.01). Moreover, the reduction in resting systolic blood pressure was higher for the high-intensity interval walking training group (P=.01).

CONCLUSION: High-intensity interval walking may protect against age-associated increases in blood pressure and decreases in thigh muscle strength and peak aerobic capacity.

Mayo Clin Proc. 2007;82(7):803-811

No comments: