Here is a curved treadmill that helps you burn more calories than a motorized treadmill. The Vortex Strength Motorless Curved Speed Treadmill has an ergonomic handlebar and a 6-position intensity lever. It has a 63 x 19″ curved running surface for HIIT workouts.
The Vortex Strength Curved Treadmill has ANT+ and Bluetooth HR connectivity. It has max user capacity of 350lbs. This treadmill has dual handlebars for high and low pushes. It has foot levelers for stability.