Respectfully, I disagree with this sentiment. Assuming you're referring to the academic years, the reality of it is that in medical school you've got one job and it's simply to study and pass step 1. As a biology and chemistry double major I'm currently 22 credits in upper division coursework and I have zero issue keeping up with the workload. Why? Because I recently took my MCAT and have all the volunteering I need to apply. The only things on my plate are coursework and research. Last semester when I was preparing for the MCAT, volunteering at both a hospital and in a hospice care center, and doing research I had trouble keeping up with 12 credits - and they were easy courses compared to the ones I'm taking now. In short, I don't think one semester of coursework is a good reflection of a students academic capacity.