Safely Progress Weekly Mileage Using a Block System
A fundamental aspect of improving distance running performance is increasing the total miles run per week. Injuries often occur when the miles per week (mpw) progression occurs too rapidly and, contrastingly, a lack of improved performance can occur if mileage is not progressed enough over time.
Pitfalls of the 10% 'Rule'
The 10% rule is often used to progress mileage and I believe this is an appropriate progression strategy overall, at the population level, but does not take into account individual differences or scenarios. For example, a completely new runner completing 2-3 miles per week can likely increase their mileage by more than 0.2-0.3 miles per week and an experienced, higher mileage runner completing 110 miles per week will likely find an 11 mile increase, per week, to be too aggressive.
Block System Solution
A solution I, and many other coaches and trainers, use is a block system where mileage is increased for a period of time before decreasing to allow the body time to adapt. Oftentimes this allows for a greater than 10% increase to occur, when it is necessary, while also providing higher mileage runners a system for increasing mileage without overtraining.
I’ll provide an example of an 8-week base building phase below that is broken into two 4-week blocks below. In this scenario, this runner is starting at 20 miles per week.
8 Week Example with Two 4-Week Blocks
Block 1 (Weeks 1-4)
Week 1: 20 miles
Week 2: 24 miles
Week 3: 27 miles
Week 4: 20 miles
Block 2 (Weeks 5-8)
Week 5: 27 miles
Week 6: 30 miles
Week 7: 33 miles
Week 8: 27 miles
In this block system, weeks 1-3 of each block serve to increase mileage by 10-20% which may be too aggressive to continue for long periods of time. However, week 4 serves to decrease mileage with week 5 (week 1 of the next block) resuming the highest mileage of the previous block.
Using Blocks to Progress Mileage Over Time
Progressing mileage in this fashion allows for three weeks of mileage progression followed by a 2 week period to accommodate to this training load, which includes a decrease in mileage and a resumption of mileage at the previous block’s greatest mileage.
This 8 week training period broken into two 4-week blocks, at this specific mileage progression, is just an example. Depending on individual differences, training blocks may include a 5-6 week progression in mileage before dropping and this would depend on observations made by your coach or your own training experience if you’re coaching yourself.
If mileage is progressed in this fashion for a long period of time, such as over two complete 16-week race-specific macrocycles, mileage progression can increase substantially while allowing the body multiple periods to adapt to the continually increasing training load.
Interested in Running Coaching?
Currently my main professional focus is on my Physical Therapy for Runners services and providing Strength and Injury Prevention Plans and Programming for Runners.
However, in May 2025, I’ll be resuming my full-fledged running coaching services. I’ll be taking on 5-10 clients for summer base building in preparation for a Fall and Winter race season. If you’re interested in these running coaching services, starting in May 2025, please fill out this form below and I’ll send more information within the next couple weeks.
