A common marathon training question athletes have when training for a marathon is whether or not they should they do strength training.  First and foremost, lets differentiate the difference between strength training and cross training.  Strength training is weighted resistance exercises such as leg press, squats, bench press, pull ups, etc.  Cross training consists of activities such as swimming, elliptical, rowing, cycling, etc.

As a general rule, strength training is beneficial because it keeps overuse injuries at a minimum by providing increased strength to balance to the body’s muscular system.  However, too much of a good thing can be bad.  If you find yourself having difficulty fitting in your run training for the marathon due to family and work obligations, then sacrificing sleep and recovery to execute strength training exercises may begin to become detrimental to your goals and fitness.

A much better use of an athlete’s time-constrained week could be executing one or two cross training activities each week of 30-60 minutes each.  This will still allow some muscular balance adaptation to occur and continue to provide aerobic benefit while potentially keeping overuse injuries at bay.  Additionally, even though yoga has limited aerobic benefit for marathon runners, it is also a good cross training exercise on your rest days as it will provide you with core strength and flexibility; two things that help keep overuse injuries at bay.