How to Increase Mileage Without Getting Injured

The 10% rule gets repeated so often it's treated as gospel: never increase weekly mileage by more than 10%. It's not wrong. It's incomplete, and treating it as the whole plan is how a lot of injuries happen anyway.

The 10% rule tracks volume. It says nothing about how your body is actually responding to that volume (soreness, sleep, recovery capacity) which means two runners can follow it perfectly and end up in very different places - one adapting well, one quietly accumulating fatigue they won't notice until it becomes pain.

What to Track Instead of Just Miles

Alongside weekly mileage, track three things after every run:

• Morning soreness the next day, on a simple 1-5 scale.

• Which side feels off, if either.

• Whether soreness fades in the first mile of your next run or gets worse as you go.

A pattern of rising soreness that doesn't fade with warm-up shows up weeks before pain does. It's the earliest signal you'll get.

When to Hold Mileage Flat

If soreness trends up for two weeks straight, hold your current mileage instead of adding to it. This isn't a setback - it's the adjustment that keeps you from needing a much bigger one later.

Bottom Line

Mileage progression isn't a formula you set once at the start of a training block. It's a conversation with your body that happens every week. The runners who stay healthy long-term are the ones actually listening to that conversation instead of just following a spreadsheet.
Not sure if your soreness is normal adaptation or an early warning sign? Apply for a free gait analysis and we'll help you read the signal correctly.

Track the pattern. Trust the pattern.

Dr. Heather Gansel is a doctorate-trained movement specialist with 25+ years in biomechanics. She works with runners virtually through Ask Doctor Heather, helping them identify and resolve the root-cause movement patterns behind recurring pain and performance plateaus. Follow her on Instagram @drheathergansel.