Length of cardio may matter more than intensity
Here's good news: You don't have to run till you drop — you just have to keep running. The amount of exercise you do may matter more than the intensity for aerobic fitness, a new Duke University Medical Center study has found. One group of the study's 133 sedentary, nonsmoking subjects jogged 20 miles a week at 65 to 80 percent of peak VO2 (maximum rate of oxygen consumption). Another group jogged or walked 12 miles a week at the same level of VO2. A third group walked 12 miles a week at 40 to 55 percent of their peak VO2. The first group had the highest VO2 gain (indicating improved fitness), but not because they exercised harder — because they exercised more. Don't worry — you don't have to run 20 miles to get similar results. Says lead researcher Brian D. Duscha: "You only need to walk briskly for 12 miles per week, or for approximately 125 to 200 minutes per week, to improve your fitness level."
What we do in life echoes in eternity.