The idea of running flat out for 20 minutes doesnt appeal to the masses, and it’s understandable.
Low Intensity Steady State (LISS) is the solution. This means that you can walk on the treadmill, or ride the bike at a pace that is moderate and allows you to still hold a conversation (all those chatterboxes at the gym finally make sense).
According to Polar.com, the ideal zone for this is:
|60-70% of maximum heart rate (Zone 1)||Weight loss, building endurance|