Every time that I read an article about marathon training I see something pertaining to the longest run in a marathon plan. Why is there so much controversy?
Every marathon runner or coach has his or her own theory about the longest run during marathon training. Some argue that 20 miles in long enough. Others argue running up to 30 miles. And some even say that 15 miles is long enough. Which theory is correct?
In my own opinion the two greatest coaches are Arthur Lydiard and Jack Daniels. These two coaches never had their runners run longer than 22 miles. My interpretation of their coaching system is that they based this distance on the length of time that a marathoner would run during the actual race. During marathon training a distance of 22 miles ran at slower than marathon pace would equal the time running the actual marathon.
My own theory about marathon training follows a similar pattern. I try to lengthen my long run in minutes to the amount of time that I project to be my finishing time. For example if my projected marathon goal is 3 and ½ hours. My longest run will be 3 and half hours at my long distance heart rate of between 60 and 75% mhr 3 weeks before the marathon.
Two drawbacks to this theory are under estimating your finishing time and running longer than three hours. Figuring out your estimated finishing time can be a challenge. There are many ways to estimate your finishing time. My personal choice is to take my latest half marathon finishing time and double it and add one half hour. For those whose finishing time projects out to be longer than 3 hours I would not run longer than 3 and a half hours.
A suggestion about longs runs during marathon training. When your long run time starts approaching three hours allow 14 to 21 days between these efforts. Three hour runs take a lot out of you both physically and mentally. Extra time is needed for the body and mind to adapt to these difficult efforts.
My theory about long runs during marathon training has helped to me set my own personal best times in the marathon. I believe this will allow you to reach your own marathon goals also.