We live in a numbers-driven society, making it easy to compare training data with those around us. In sports such as running, there can be pressure to fall within a certain weight range. And dance companies and dance schools often look at BMI (Body Mass Index) to determine if their dancers are "in shape."  As you'll hear on this week's episode, comparisons like these can be dangerous because they don't account for the variety of ways that each individual is different.