Running vs. Stationary Bike

Biking is easier on your knees. Some day, that will matter. Both are good exercise. I can't run, but I'd suggest both on different days if you are able. Alternating could help to avoid boredom, over training and reduce the risk of injury.

Okay, So I have been riding my stationary bike 30 minutes a day about 4-5 times a week, I am never sore but I sweat my butt off and get out of breath and my heart races. I just started running, it doesn't take as long but makes me super sore the next day and I sweat but not as much as on the bike. MFP says that stationary bike burns more calories...should I continue to ride my bike because it takes longer and makes me sweat more or should I run because it makes me sore? maybe a stupid question but..i wanna know!

Running has more impact and more eccentric loading--that's why it make the legs more sore at first.

In most cases, unless one works to become a well-trained cyclist, it is "easier" to work harder when running than riding a stationary bike.

The MFP calorie number for stationary cycling are not very accurate IMO.

Sweating is not an indicator of exercise quality. People often sweat more on bikes because they are sitting in one place so there is no air movement.

This is not an "either/or" argument. As someone else said, the two can be a good combination.