Level 1: Low intensity training, provides metabolic and emotional health benefits. Training at this level can lower cholesterol and improves blood pressure. This level represents 50% to 60% of HR max.
Level 2: This level corresponds with low to moderate exercise intensity, burns more calories than performing at level 1. Individuals at this level are able to carry on a conversation without any problem. This level is performed at 60% to 70% of HR max
Level 3: This level requires the ability to sustain exercise over a long period of time without fatigue. Improvements at this level occurs by increasing mitochondrial density and improving fat utilization, thus resulting in more total calories expended per exercise minute. This level is performed at 70% to 80% of HR max. This level can be challenging.
Level 4: This level is performed at 80% to 90% of HR max. This level creates training changes that lead to improved aerobic capacity. This level is for more fit individuals, those wanting to improve speed for performance.
Level 5: This level is performed at 90% to 100% of HR max. This level requires near all out effort, thus can only be sustained for short periods of time. The lower end of level 5 can be sustained for 20-35 mins (5k race, for example) by well conditioned athletes. The higher end of this level can be sustained for only 2-5 minutes.