Marathon Training Schedule: Deep Water Running

It's probable that at some point during your training, you will be sore, a bit achy, or have some nagging pain that is telling your body to slow down for a few days. While complete rest is often the prescription of choice, another more active alternative is deep water running.

Deep water running means requires a pool of at least chest deep water, and while a flotation belt is helpful, it is not absolutely necessary. Most gyms and YMCA's will have flotation belts that they use for water aerobics class, which are available for member use.

Deep water running can be a great workout to include as part of your marathon training schedule, because it has zero impact, yet it gets your heart rate up, and mimics the motion of running. It's important to concentrate on perceived effort since distance won't be comparable. Use a stopwatch to do intervals of hard/easy efforts. A good workout is 2 minutes hard, 1 minute easy, repeated 5 times. Then rest for a few minutes, and repeat with 5 more sets.

Some people actually use old running shoes in the pool. It may give you a better feel for your running stride, and it will definitely act as additional resistance. Deep water running is great for rehabilitating muscular problems (torn or pulled hamstrings for example), since you can work through a range of motion very slowly, without any quick movements. If you are using it for rehabilitation, gradually increase your range of motion over and make sure you don't feel any twinges of pain in your injured muscle. The purpose of deep water running in this case is to stretch and strengthen your muscle gradually. Any aerobic benefits are a second priority.

I personally like this book for good water workouts:
Water Workouts: A Guide to Fitness, Training, and Performance Enhancement in the Water