While training for a marathon most people tend to focus on mileage, along with maybe some speed work, intervals, or a fartlek or two and overlook another important training tip, REST! Early on during training the miles seem reasonable and most of us can usually power through a workout without much of an issue. However, then comes the weeks of long runs of 18, 19, and 20 miles with mid week runs of 8, 9, and 10 miles (my training topped out with a long run of 20 miles and a mid week run of 10 miles) and no matter how quick you are, how experienced you are, or how in shape you may be what you do the day after these runs add to or take from the quality of that workout.
Rest days are built into all of the training schedules that I have seen and they are there for a reason. In my training, I usually take Thursday and Sunday off. Rest days allow your body to recover form the previous day’s run by allowing your body time to restore the Glycogen (fuel) stores in your muscles. Also running any distance produces small tears in the muscle fibers and the rest allows the body to literally repair itself which through this process speed, endurance, and strength are all improved, all of which are key to any type of running success.
On top of the repair/regeneration factors, rest will also help prevent overuse injuries such as shin splints, IT band issues, planter fasciitis, or a variety of other issues. I have been fortunate, for the most part, and have been able to avoid many of these injuries, however, last fall I had a nasty case of shin splints and I was shut down for 2-3 weeks (probably should have been longer) and for someone who has runs 25-30 miles per week, this was a killer. If you are training for the Chicago Marathon, which is now less than a month away, this is not something you want to deal with at this point.
Personally, I feel that one of the most important aspects of rest is something that is often overlooked, and this is the mental benefits. During my training I cherish my rest days as they are days where I do not have to worry about how far I have to run, what the weather is like, or anything else. I am able to go home after work, have a nice dinner with my wife, and just relax. Typically my harder runs are on Friday and Saturday with pace runs on Friday and long runs on Saturday; having a rest day on Thursday allows me to go into those runs mentally and physically fresh which helps increase the quality of those workouts. The rest day also gives you a chance to forget about a bad run or another day to enjoy the success of a great run. Do your best to completely shut it down on these days, enjoy a good meal with your spouse or significant other (but nothing crazy), watch a ball game, or catch up on a book; just be sure to give yourself that mental break.
As I mentioned, I tend to take my rest days on Thursdays and Sundays and I generally take these days off completely, however, if you feel the need to do something, try to limit it to one of the two days, and be sure to keep it as low impact as possible. This could include swimming, biking (easy) or some time on an elliptical machine. No matter what you do, be sure to take it easy. Sometimes a real easy day like this can help get the soreness and lactic acid out of your legs which will help on your next run.
If you take nothing else form this, take that a rest day after a hard training day can help solidify the benefits from the previous training day. The rest days are the glue that holds the balance of your training week together.
Happy running this week as you continue to build your mileage, endurance, and most of all confidence.