If your cat eats dry food, he's more prone to constipation than a cat who eats wet food due to the decreased moisture content. Your vet will do a simple test to determine your cat's hydration level by pinching a fold of skin on his shoulders and pulling up. If it snaps back into place when released, he's well hydrated.
Comparing the Calorie Burn. In terms of calories, a 30 minute treadmill running session at 6mph for an 155lb adult will burn around 350 calories. The same size adult will burn around 260 calories in 30 minutes on a Spin bike at a steady pace. However, a Spinning class is much more intense so you can expect to burn anywhere from 400-600 calories if you push yourself.
A 200-lb. person will burn 120 calories with a leisurely bike ride, but traveling between 12 and 14 mph will burn 264 calories in 20 minutes. A 240-lb. person will burn 144 calories in 20 minutes, while more vigorous biking will burn 317 calories.