Since Dan is delving into cardiovascular epidemiology, I've been enabled to ask a slightly off topic question. Moderate intensity exercise decreases the rate of progression to diabetes in high risk groups, and is also associated with decreased cardiovascular risk. Here's the question: are there any data comparing the relative value of say, 3 hrs of exercise on Saturday vs. 30 minutes of comparable intensity exercise 6 days a week? I've poked around a bit on PubMed and haven't found anything useful. I'm hoping one of our resident exercise physiologists can point me in the right direction.

Ken