4 Days of Exercise a Week May be Better for you than 6. (At least if you are an older woman.) http://well.blogs.nytimes.com/2013/02/13/why-four-workouts-a-week-may-be-better-than-six/ Kinda' fascinating. Two days of aerobics and two days of strength training were just as good as 3+3 and the women involved burned more calories on a 2+2 than on a 3+3. The 1+1 women showed just as much increase in fitness as the other two groups, but burned less calories at rest than the 2+2. The 3+3 burnes the least number of calories at rest. As I'm a middle-aged woman, I'm going to extrapolate and use this as evidence that my 4 time a week strategy is sufficient.