How long does it take to build up stamina in mountain biking?
It depends on your training and how fast you can recover. To build stamina the best way is a hard one, it’s called interval training. You need to be able to put out power hard and fast then in a min. amount of time recover then be able to do it again. Next you will also need to learn how to pedal in circles, one legged pedaling will help. The first few times you do this it will feel funny and you’ll notice how choppy your pedaling is, but you will get better at it. You need this because unlike road riding you have to worry about traction and picking a line. Over time you will get better at climbing, technique is key and pedaling smoothly will get you to the top.