The question of how quickly you can improve your fitness is not an easy one to answer. Why, because it depends on many different factors! And some people may see results faster than others. The good news, however, is that if you stick to a consistent training program throughout a four week period, you'll be surprised at just how much you can achieve! Starting From Scratch: What You Need to Know If you're starting from scratch, that is if you really wouldn't call yourself fit at all, then it's important to know that you're not going to able to run a marathon after just four weeks. However, it might be possible to run a 5K in four weeks, if you're careful and you're not completely unfit to begin with. Even if you have a base level of fitness, one important thing to remember is that your body needs to adapt to whatever kind of exercise you're doing. Even if you don't get too out of breath running, for example, you might find...