Biking is a great exercise. You can choose to make it as difficult as you like. Start with a flat land and start raising the bar. Make it a trail over highlands and keep getting on rockier terrains. This is why the concept of mountain biking can be quite an amazing thing for the entire body.
Start exercising with mountain bikes at a flat land and a fixed gear. The exercise can be done for as much as an hour. In the eventual run, it can lead to enhancing knee range of motion. Arms and shoulder is regularly twisted and jarred thus leading to stronger shoulder pads and biceps. Also, the knee undergoing strong maneuvers is held more strongly with time. Long drive helps in perfectly sculpting the calves and also the quadriceps.
Even therapeutically, this helps the cardiovascular system and metabolism a lot. Energy level is also heightened.