You also need to clearly identify what your definition of obese is -- are you using a strict BMI definition of anyone >30? A 50 year old 6'5'' man who weighs 260 pounds, while having a BMI of 30.8 and thus clinically identified as obese, may have no issues performing CPR, making patient transfers, staying on his feet 12-13 hours at a time, etc.. While a 30 year old 700 pound nurse may have severely limited physical activity.