Assault Fitness AirRunner

The Assault Fitness AirRunner burns 30% more calories than a motorized treadmill at the same perceived effort, because there's no belt doing work for you. Its slatted belt lasts 50% longer than traditional treadmill belts, as confirmed by CrossFit Games athletes who train on it. Outperforming the Rogue Ohio Bar (#6) in cardiovascular intensity, this motorless curved treadmill forces you to generate every step—zero electricity, zero maintenance, zero coasting. With a 400 lb user capacity and a 5-year frame warranty, it's the ultimate tool for interval training.