For instance, most veteran marathon runners apply the 10% rule whereby they only increase their weekly mileage by a maximum of 10% in any week. Not only does this training schedule avoid the most frequent training injuries but they may also build their endurance levels at a more normal pace than what most first-time marathoners do. So if they have built their weekly mileage to say 25 miles then the next week they would train an additional 10% of this. That means they would train close to 27-28 miles within the following week of their marathon training schedule. Rest can also be an additional important aspect of marathon training. For instance, if you run each and every single day then it doesn’t give your system the opportunity to recover from the exercise. So what most veteran marathoners include into their marathon training plan is really a number of rest days. For example, if they do a lengthy training session on a Sunday, most would take the next day off from training so that they can give their body a opportunity to recover.