The so-called natural environment fitness refers to outdoor aerobic training, such as mountaineering, running and cycling. And improving physical fitness refers to a wider range, which can be outdoor or indoor fitness clubs, where there are aerobic treadmills, spinning bikes, fitness classes and so on. Yes, there is also anaerobic training-equipment (barbells, dumbbells, large mechanical fitness equipment, etc. ). The former is the simplest and most effective way to improve physical fitness. In fact, there is little difference between the two functions and effects, and both can improve physical fitness. Only if the latter wants to develop muscles in anaerobic equipment training, choose this one. It will be more interesting to exercise in the gym. ...