Pro racing cyclists post very high figures for all metrics of aerobic efficiency... So it's well-proven.
(agian, if done with proper training procedures and techniques)
I don't know the extent that roller blading has been so studied. There's no reason it shouldn't be a fine aerobic exercise, and it does tend to involve more of the body than does cycling... The arms and upper body get a lot of use especially when sprinting.
I imagine the safety factor would be similar... But bikes have far superior braking ability.
Better for what? What criteria? There is no best exercise for all people. For some weight lifting is best. For others it is Yoga.
Biking and inline skating (Rollerblade is a company. People bike, they don't Specialized.) are very similar and would be considered alternatives to running.
They are more similar than different so a lot comes down to your preference.
They are both good for easy cruising or pushing for speed (and higher exercise level) as your whim dictates.
They are similar for speeds with biking being a little faster than inline skating (record for the marathons run in the 27 mph range)
Both are highly mobile but if you want to go exploring, it is a bit easier to toss skates in a bag and take them somewhere.
Skating uses a bit more energy to go the same distance.
Skating uses more muscle groups up into the core muscles.
Biking can go on surfaces (like crushed rock trails) that skating cannot.
Skating is a lot less expensive. You can get a pretty decent pair of skates for the price of a really cheap bike.
Biking is easier for commuting (you can carry things easier and the ability to go places that skates are a problem)
I tried both running and biking on a regular basis before I had ever skated on inlines. Running was slow and boring. I didn't have a rack for my car to go exploring and I got tired of the same routes on a regular basis (places where I could bike at medium speeds safely). I quit them both.
A couple friends invited me to skate with them (www.roller-dome.com) and I found a new sport. I can toss them in the car and go exploring in different areas. I also found a club with a lot of friends (there are more bike clubs than skating ones).
I'd say, roller blading. it trains and it firms your lower body. The natural side-to-side motion your legs get from inline skating is ideal for trimming the thighs, strengthening the quads, and lifting the glutes. It's also perfect for people looking for a low-impact aerobic activity that doesn't put a lot of pressure on their joints.
the other thing is that it improves coordination: It'll take a bit of practice in the beginning, but it improves flexibility and coordination tenfold. The activity forces you to even out your balance and find your center of gravity. In my opinion the balancing that you need to stay up right might also build up your core muscles (ie abs and lower back. Just like a consistent yoga practice, you'll find that continued inline skating will get you more graceful during your everyday activities.
Biking. Really strengthens your legs when you keep on pedling. Roller blades, eh I don't see anyone doing that a lot. Better go with biking.
Rollerblading is great! it tightens the legs and core, i definitely prefer rollerblading. Biking is fun but i love the flexibility and movement of skating, I feel much more focused when skating.
