I would suggest that you spend 75% of the time you are doing cardio at around 75% of your Max HR (Age -50). This will allow you to work longer and burn more calories while building a baseline of endurnace. I would then spend half of the remaining time doing intervals with max effort and the the other half in a below 75% cool down/recover mode I'm saying this as someone who spent a long time maxing out too much and became overtrained and tired. For me it's become about how often I can show up and I can do that more by modifying intensity. |