How good cardio is biking?

[Chip2006uk]

I got a push bike for christmas so I can save money on busfare to the gym (£50 a month!) and Ive just been out for a ride just now.

Basically I was wondering how good is biking for cardio compared to roadwork or interval sprints? I was going to the gym today to do some treadmill sprint intervals but it was closed so instead I decided to go on a 3 hour long bike ride around the city, I definately felt my legs getting worked but how is it in terms of pure cardio?

I was riding up and down alot of hills and also with a big heavy bag on my back and I did find myself slightly out of breath at times but nothing compared to how Id be if I was doing sprints or something.

[*2TOUGH*]

i think its better, as you work more of the "important" muscles and you can work out longer.... or faster depending on how explosive you want to be..

[ScottDBA]

Basically it depends on your heart rate and time.

If you're getting your heartrate up higer for longer, it will be betterthan running.

Not getting as high, or it's the same but not as long as your runs, then it will be worse.

It is great for building endurance in your legs though.