fbpx Skip to content


Marathon Training 101

There are more than 300 marathons just in the United States each year, with hundreds of thousands of people running them. Chances are that one or two of your clients want to do one. So how do you train them for a marathon? Consider the following strategy.



The number of miles your clients run each week is the most important part of their marathon training. To run 26.2 miles (42.2 kilometers), your clients need to become as aerobically developed as possible. Running lots of miles—totaling up to 50 in peak training weeks—helps with this in many ways.

Long Runs

Long runs present a threat to the muscles’ survival by depleting their store of glycogen. Depleting muscle glycogen forces muscles to rely on fat as fuel. The human body responds rather elegantly to situations that threaten or deplete its supply of fuel, synthesizing and storing more than what was previously present, thus increasing endurance for future efforts.

The long run should not comprise more than about a third of your clients’ weekly mileage. Clients should run at a comfortable, conversational pace (about 2 minutes per mile slower than 5K race pace, or about 70%-75% of maximum heart rate). Lengthen their long run by 1 mile each week for 3 or 4 weeks before backing off for a recovery week. Keep adding miles until clients reach 21-23 (or about 3-3┬¢ hours, whichever comes first), and have them do their longest run 2-3 weeks before the marathon.

Lactate Threshold Runs

The lactate threshold (LT) is the fastest running speed above which lactate production begins to exceed its removal, with blood lactate concentration beginning to increase exponentially. It demarcates the transition between running that is almost purely aerobic and running that includes significant oxygen-independent (anaerobic) metabolism.

As clients train at LT pace, their LT pace increases, and what was an anaerobic intensity for them becomes high aerobic. Since optimal marathon pace is only about 15-20 seconds per mile slower than LT pace (with the difference between the two getting larger as performance level declines), the goal of marathon training is to increase your clients’ LT pace and their ability to sustain as high of a fraction of their LT as possible.

Long Intervals

Long intervals (3- to 5-minute periods of hard running with 2- to 4-minute recovery periods in between) run at the speed at which VO2max occurs provide the greatest cardiovascular load. This is because your clients repeatedly reach and sustain their maximum stroke volume, cardiac output and VO2max during the hard running periods. Long intervals are the most potent stimulus for improving VO2max. The higher your clients’ VO2max is, the higher their aerobic ceiling.

The Taper

Progressively reducing, or tapering, the training may be the most complicated part of marathon training. To maintain fitness when tapering, the intensity of training seems to be more important than either the training volume (weekly mileage) or its frequency. To taper your clients’ training, reduce their weekly mileage exponentially, include some interval training to maintain training intensity and tell them to increase their carbohydrate intake (to at least 70% of total calories) to increase the amount of glycogen stored in their muscles for race day. As clients get closer to the marathon, reduce the volume of intensity by reducing the number of intervals in each session.

The exact length of your clients’ tapers will depend on their prior training load, their level of fatigue and their genetically predetermined ability to retain their training effects while reducing the training stimulus (i.e., how quickly they lose fitness).

During the first week of the taper, keep the intensity high by including one long interval workout and one LT/LSD combo run. Decrease the intensity slightly during the second week, with two short- to medium-distance runs (5-10 miles) at marathon pace. The week of the race, have clients do one interval workout early in the week at either LT pace or slightly faster, cutting back on the pretaper number of reps. Also during the final week, schedule a daily reduction in mileage over the last few days, mirroring the pattern of the weekly reduction.

For specific examples and sample marathon workouts, refer to the complete article, “Marathon Training 101,” in the June 2009 issue of IDEA Fitness Journal, or read it online in the IDEA Library. Also, check out Karp’s session, “Chasing Pheidippides: Marathon Training 101,” at the IDEA World Fitness ConventionÔäó, August 12-16, in Anaheim, California. To register, visit the IDEA website.


Concerned about your place in the new fitness industry? We have 40 years of experience supporting pros just like you! Let’s create a new wellness paradigm together—IDEAfit+ is the extra edge you need. Once you team up with IDEA, be sure to take full advantage of all the benefits of membership.

Jason Karp, PhD

A professional running coach, freelance writer, fitness consultant and PhD candidate in exercise physiology at Indiana University. He coaches runners of all levels through RunCoachJason.com.

When you buy something using the retail links in our content, we may earn a small commission. IDEA Health and Fitness Association does not accept money for editorial reviews. Read more about our Terms & Conditions and our Privacy Policy.


Subscribe to our Newsletter

Stay up tp date with our latest news and products.