How to Structure a Training Cycle for Half and Full Marathons

by GRP Run road athlete Katie Kellner

The most effective way to build fitness and get faster over time is to organize your training into cycles. Training cycles are 14-20 week blocks of running with the focus on getting fit for a particular race. Cycles compound on each other, meaning that completing multiple training cycles in a row will make you fitter over years of training. Training cycles consist of five main components in this order: rest, mileage build, peak training, taper, and race. 

Rest (1-2 weeks)

Every training cycle should start with a period of rest. Periods of rest and low-intensity training in between cycles are essential for allowing the body to recover and ensuring that you hit your peak fitness around race day. The body can’t train hard all the time or it will burn out and reach a point of diminishing fitness returns. Plan to take downtime from running for 1-2 weeks about 12-18 weeks out from race day. The number of weeks out you should take a break from running depends on your fitness level and experience. Those coming in with a higher fitness level will need less time to train for a half or full marathon and therefore should take their rest time about 12 weeks out. Those that are newer to running should take their rest about 18 weeks out from a race. 

Mileage Build (3-5 weeks)

During this phase of the training block, you should gradually build up their weekly mileage. Start low, include more rest days, and increase about 10% of mileage each week to avoid injury. The length of time of the mileage build will depend on fitness level and experience. Newer runners will need more time to gradually build and let their muscles adapt to the volume. During this phase of training, you should not do any interval, tempo, or high-intensity training. Increasing intensity at the same time as volume can lead to injury. 

Peak Training (8-10 weeks) 

The peak training phase of a half/full marathon block will be the hardest chunk of a training plan. This is when you should consider starting speed, strength, and tempo workouts to add in an intensity stimulus. The highest mileage and hardest training weeks should be 3-6 weeks out from race day. During this phase of training, you can also compete in shorter races, if desired.

Taper (2-3 weeks)

During the taper phase of training, gradually decrease your mileage to prepare for race day. You can continue with high-intensity workouts, but they should be shorter and designed to maintain fitness, not build fitness. Some find a 3 week taper beneficial because it is more gradual and helps the legs feel fresher. Others start to feel stale if their taper is too long and prefer a two week taper. The taper is also a good time to focus on getting rest and prepping for race day. 

Race

If all goes as planned, you should be ready to go for race day! After race day, take some rest from running and start the cycle all over again!