Looking for some info on what's the best or advice on the differences between BMXs and Mountain bikes.
I own a mountain bike but as a kid, I loved my one-gear bike which I found I was the one doing the most workout going uphills, whereas my friends had mountain bikes and had ease getting up huge hills. And generally I liked the feel of being always in one gear going fast and doing jumps.
Anyway, I know this defeats the purpose of a mountain bike, but the majority of the time I'm always on the mid-highest gear - lower RPM on flats and hills as I love working the muscles.
Would you get as much workout on a BMX compared to a Mountain Bike or really makes no difference?
If you're going to be "mashing" in high gears, watch your knees. Pushing your way up a hard hill puts a lot of strain on your knee joints and may cause you to develop long-term injury over time, especially with the typical riding position on a BMX. The advantage of having multiple gears is to save wear and tear on your joints by making cycling an aerobic exercise (think swimming) rather than a weightlifting one, and builds up your knee support tissues gradually. Most single-speed mountain bikes have much lower gearing than their on-road counterparts. From my experience, when I switched from my SS road bike to a geared one, the amount/distance I did went way up, which definitely increased the equivalent "exercise" I got.