Spin classes use specialized stationary bicycles featuring a mechanical device to modify the difficulty of pedalling, specially shaped handlebars, and multiple adjustment points to fit the bicycle to a range of riders. Weighted flywheel simulates the effects of inertia and momentum when riding a real bicycle resulting in burning calories, developing muscle tone and positively impacting your cardiovascular and respiratory systems. The pedals are equipped with toe clips as on sports bicycles to allow one foot to pull up when the other is pushing down.