This is a question I get quite often and to be honest, one that is hard to give a definitive answer to. The reason it isn’t easy to answer is because there are a number of factors involved to substantiate improved health and fitness. Factors to be considered are recovery ability, nutritional intake, adequate rest, outside stressors, time, and much, much more. I have some clients that will train with me three times a week. Quite a few folks will come twice each week and I have a good selection of people training only once per week. The clients who see more frequency of exercise movement seem to do the best with getting stronger and in better shape with regards to cardiovascular improvement as well as improved flexibility. Those who train once-a-week with me are encouraged to stay active during the week. In fact, I encourage all my clients to stay active in some way during the week using the pillars of my Five Components of Health & Fitness (pdf download). Taking care of your health is not a part time job, it’s something that needs to be addressed on a constant basis but it doesn’t need to be so mentally and physically laborous as most folks think. Take a quick look at the “Five Components” and you will see what I’m talking about.