Why Speed Work and Hills Still Flare Your Plantar Fascia (Even When Easy Running Feels Fine)
- Marie Whitt
- Feb 3
- 6 min read
At this point, your plantar fascia doesn’t hurt that much anymore.
You notice it during the first few steps in the morning, maybe a 3 out of 10.
But honestly?
It fades within a minute or two.
By the time you’re brushing your teeth, you’ve already forgotten about it.
Your easy runs feel fine.
Long runs: you can finally find your grove again.
Maybe your warm-ups feel a little tight, but nothing alarming.
So you tell yourself: I think I’m past this.
And then you hit a speed workout.
Or a hill session.
Or maybe you flirt with both.
You push hard, because your legs feel good and your fitness is there.
And the run itself feels okay. Maybe even great.
But the next morning?
That quiet, manageable stiffness is suddenly not so quiet. It's nearing cow-bell loud.
Now it’s a 5 or 6 out of 10. And panic sets in.
Did I just undo weeks of progress?
Do I need to take another day off?
Another week?
Do I have to scrap speed work and hills… again?
This is the phase where runners feel like they’re stuck in a loop.
They have a good week, one “normal” workout, setback...and it starts to feel like you’ll never quite catch up.
The problem isn’t that you’re doing too much running.
The problem is your foot isn't 100% ready yet.
You've made it past the spiciest part of your plantar fascia rehab, but just because symptoms have calmed down for the most part, doesn't mean your foot is actually at 100% again.
The trick here:
You're missing running specific strength exercises that not only help make your feet muscles, calves, and plantar fascia stronger...
But you also need exercises that help build tolerance and capacity for power, for that spring-action the bottom of your foot needs to provide in order for speed work to be speedy and hill work to be...well... not awful.
So let's give you the missing pieces you need:
the running specific strength and rehab exercises to get you back to speed and hill workouts without next-morning flares while also waylaying those fears of "oops, did I run too hard and ruin all my progress?"
If I Can Run Easy or Long Runs Without Plantar Fascia Pain…Why Do Speed Work and Hills Keep Setting Me Back?
Let's compare and contrast.
Let's say your easy run is 5 miles, on a relatively flat path.
Take that same path. Make it hilly.
Or take that same distance, but now make it speedy.
Same mileage, different efforts, right?
Your feet feel the difference, too.
Especially your plantar fascia which experiences greater loads during speed or hill workouts compared to a chill, flat-ish easy run.
Because even though speed workouts and hill repeats don’t always hurt during the run, they still place very different demands on your foot compared to easy mileage.
Speed work increases the force your plantar fascia experiences with every foot strike. And hills also create an increase in that force, but also the magnitude of the "push" your toes experience traveling into greater extension as your charge up a hill.
Both types of workouts require your plantar fascia to tolerate higher strain, repeatedly, and right now in your current stage of rehab, it simply hasn’t been trained for that level of intensity yet.
That's why towel scrunches, marble pick ups, and wimpy theraband ankle exercise make me cringe as a runner and a physical therapist.
Your feet deserve better. If your rehab exercise do not become "intense" in some form or another by the time you're getting closer to full return-to-run, your feet are not properly prepared for your hardest workout.
So while your foot can handle:
Easy running
Steady mileage
Lower-intensity impact
It isn’t prepared for:
Max-effort push-off
Rapid force production
Repeated high-load toe extension
That mismatch is what causes the next-day flare, not damage, not failure, and not a sign you need to stop running altogether.
What you’re missing isn’t more rest.
It’s a bridge to gap that "Intensity Readiness Phase"...
A phase of targeted strengthening that builds your plantar fascia’s tolerance from “mostly fine” to “speed- and hill-proof”, without blowing things up in the process.
And that’s exactly what the exercises below are designed to do.
The Final Stage of Plantar Fascia Exercises for Runners Who Want Their Speed Back
Circuit:
3-4 sets each // body weight to medium/heavy weights
HEAVY Single Leg (SL) Calf Raises: SHOES OFF
4 sets x 8 reps, RPE 8
3 secs up/ 3 secs down
Runner's Lunge SL bent knee calf raise
3-4 sets x 12 reps
once you can complete the iso hold below, add towel roll under front toes during reps
isometric hold: 3 rounds x 15-20 sec hold
SL Calf Raise with Towel Roll: SHOES OFF
3 sets x 8-12 reps (body weight)
once you can complete 8+ reps with ease, you can add a medium-heavy weight.
Plantar Fasciitis Rehab for Runners: How to Train Speed and Hills Hard Again
HEAVY Single Leg (SL) Calf Raises: SHOES OFF
I said what I said: SHOES OFF
THE SECRET: I want you to think of your shoe as an exoskeleton. It provides additional external support for your foot and ankle. Which is great when we're first starting to rehab your plantar fascia because we need the extra assist. However, as we move away from those "beginner" exercises and begin to get you ready for higher intensity challenges like hills and speed, we need to remove that extra support.
Taking your shoe off while doing single leg calf raises is one of the EASIEST ways to make your feet/ankle exercise specific to strengthening your plantar fascia. Because now, the only support is you. Your plantar fascia is now under more strain with more load which creates the tissue adaptation and strength that you need.
Be sure to pay attention to that RPE of 8 and count your 3 seconds traveling up into that calf raise and the 3 seconds traveling down from the calf raise. What you'll notice here is that it's HARD to get to the tippy top of your calf raise. If that's the case, you need to go lighter with your weight. At this stage in rehab, we need to train the end of range of your plantar flexion to place the greatest strain/work on your plantar fascia.
Runner's Lunge SL bent knee calf raise
think of this as your stepping stone.
PRO TIP: I like this exercise and the isometric version because we can prepare you for the next exercise (which is the money maker). But sometimes if we jump right into the next exercise, you flare, it hurts, it's not a good time.
So by using this knee bent calf raise variation, we can continue to introduce load directly onto you plantar fascia in a more end-range position that also looks like running, to give your foot a preview of not only the next exercise, but the various stride positions you'll find yourself in as you return to speed work.
If this exercise immediately feels easy, jump to the isometric version. If you can breeze through that, go ahead and add the towel roll underneath your front toes and do your reps in that set up.
SL Calf Raise with Towel Roll: SHOES OFF
This is a LOT.
THE REASON: if we think of your plantar fascia like a rubber band under your foot, we are stretching that thing to the max in this position. This is good from the physioligcal stand point of the greater the load and strain we place on your plantar fascia especially in end-range tip toe positions like this, the stronger we can make that connective tissue and the greater likelihood we can reduce speed work or hill flares. However...
I need you to start with SHOES OFF. And only body weight for starters.
If you can do 8+ reps here, getting to the tip top of your calf raise easily, now you can start adding a light/medium weight (or go heavier) but you have to still reach the tip top of your calf raise!
WRAPPING UP
This is the phase that gets you your speed back.
If speed work or hills are the only things that keep setting your plantar fascia back, that’s not a sign you’re fragile.
It's a sign you’re in the Intensity Readiness Phase.
Your foot can handle mileage.
It can handle easy and long runs.
What it hasn’t been trained for yet is repeated, high-force push-off at end range, the exact demand that speed and hills place on your plantar fascia.
That’s why the flare shows up the next morning.
Not because you damaged anything.
Not because you “overdid it.”
But because your current capacity doesn’t quite match your training demands.
The exercises in this phase aren’t about calming symptoms anymore.
They’re about bridging the gap.
By progressively loading your plantar fascia without the crutch of your shoes, training slow, controlled strength through full range, and gradually increasing intensity, you’re teaching your foot how to tolerate the exact forces required for fast running and climbing hills.
This is the final piece that turns:
“I think I’m better?”
into
“I trust my foot again.”
Stick with these exercises even as things start to feel good.
That consistency is what keeps your plantar fascia symptoms at bay, not just pain-free for a week, but capable of handling hard training without the next-day penalty.
You’re not behind.
You’re not starting over.
You’re building the last layer of strength your foot needs to run fast, strong, and confident again.
And that’s where the real progress happens.
Until next time running fit fam...
Dare to Train Differently,
Marie Whitt, PT, DPT //@dr.whitt.fit
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