When you’re a high-level athlete where a fraction of difference in your performance can be the difference between silver and gold your training needs to match with incredible specificity and consistent intensity. For the rest of us, it’s important to assess why we're working out and what results we’re looking for. In this world of fitness it’s common for people to draw lines in the sand and designate something as a waste of time. Slow, low intensity cardio, walking, flow, kettlebells, isolation exercises, HIIT, and the list goes on. 

What about if you can get better results doing something else? What if all the research indicates that type X cardio will give you what you want at a faster rate than type Y? Most people will go all in at least for a little while. What’s more important is which cardio or type of training will get you results even if it takes a little longer IF it’s something you enjoy and will actually be...