Speed walking lets you condition the body without letting it adapt to the workout. Many aerobics routines lose their effectiveness at burning fat as the body adapts to them, but speed walking challenges the body at each workout. It’s good for you if you have joint issues because it is low-impact. Walk as fast as you can for 15-20 minutes. Attempt to beat this distance the next time. Experts opine that this can be more challenging than jogging.