Arch pain during exercise is most often caused by overload on the plantar fascia, a thick band of connective tissue that runs along the bottom of your foot from heel to toes. This tissue absorbs and distributes force every time your foot hits the ground, and repetitive impact from running, jumping, or even brisk walking can cause tiny tears in its fibers. Between 5% and 17.5% of athletes develop plantar fasciitis, making it the single most common source of heel and arch pain in active people.
But the plantar fascia isn’t the only possible culprit. Your foot’s shape, your shoes, your exercise surface, and how quickly you ramped up your training all play a role.
How Exercise Damages the Plantar Fascia
The plantar fascia is made of type I collagen fibers arranged in parallel lines running lengthwise along your foot. This structure is excellent at handling tension along its length, like the pull that happens when you push off your toes. It’s far less equipped to handle compressive or perpendicular forces, like the downward crush of your body weight hitting the ground with each step.
Two moments during your stride put the most strain on this tissue: right after your heel strikes the ground and your foot begins to absorb your weight, and again as you transition from midstance to pushing off your toes. During both of these phases, the fascia is pulled tight between its two attachment points. When the load exceeds what the tissue can recover from, microscopic damage accumulates in the collagen fibers, particularly where the fascia attaches near the heel. Despite the name “plantar fasciitis,” this process is more about tissue breakdown than active inflammation. It’s a repetitive stress injury.
The longer and more frequently these forces are applied, the faster the collagen degrades. This is why arch pain tends to creep up on people who suddenly increase their mileage, add hill workouts, or start a new high-impact exercise routine without building up gradually.
Your Foot Shape Changes the Equation
Two opposite foot structures can both lead to arch pain, for different reasons.
Flat feet (or feet that overpronate) roll too far inward with each step, collapsing the arch toward the ground. This stretches the plantar fascia beyond its comfortable range and disrupts the natural alignment of your ankle, knee, and hip. Overpronation also weakens the muscle on the inner side of your lower leg that normally helps absorb tension in the fascia. When that muscle can’t do its job, the fascia takes on even more load.
High arches create the opposite problem. A high arch keeps the plantar fascia in a shortened, rigid state, and the foot doesn’t roll inward enough to absorb shock effectively. Instead, you walk and run on the outer edges of your feet, concentrating pressure on the ball of the foot, the heel, and the outer toes. Over time, this leads to repetitive strain injuries including arch pain, ball-of-foot pain, and outer ankle tendon irritation. High arches can also cause secondary problems further up the chain, like knee and back pain.
Worn-Out Shoes Are a Hidden Trigger
Running and athletic shoes lose meaningful arch support after about 300 to 500 miles of use, which works out to roughly 6 to 12 months for most regular exercisers. The midsole foam compresses permanently, the heel counter softens, and the shoe stops doing its part to distribute impact. If your arch pain appeared gradually and your shoes are more than six months old, replacing them is one of the simplest fixes available.
Insoles wear out even faster. If you use removable inserts, plan to replace them every six months or sooner if you notice them flattening out.
Your Exercise Surface Matters
Not all ground is created equal when it comes to the force your arches absorb. Research comparing treadmill, concrete, and grass surfaces found that treadmill running produces lower peak pressures across the entire foot compared to running on concrete. Concrete generated significantly higher pressures at the forefoot and total foot compared to grass as well.
Interestingly, your body does partially compensate for harder surfaces by adjusting ankle, knee, and hip flexion to cushion the blow. But this adaptation has limits, and if your plantar fascia is already stressed, switching from concrete to a treadmill or softer outdoor surface can reduce the load enough to let symptoms calm down.
Stretching and Strengthening That Help
Daily stretching of the plantar fascia and the calf muscles is one of the most consistently effective treatments for arch pain. Clinical trials show that regular stretching improves pain scores, daily function, and even sports performance within about eight weeks. Combining stretches with strengthening exercises for the foot and hip produces additional gains in stability.
A few approaches with good track records:
- Plantar fascia stretch: Sit down, cross the affected foot over your opposite knee, and gently pull your toes back toward your shin until you feel a stretch along the bottom of your foot. Hold for 15 to 30 seconds, repeat several times, and do this before getting out of bed in the morning.
- Calf stretches: Stand facing a wall with one foot behind you, heel flat on the floor, and lean forward until you feel a stretch in the back of your lower leg. Do this with both a straight and a slightly bent back knee to target different parts of the calf.
- Towel curls: Place a towel on the floor and scrunch it toward you using only your toes. This strengthens the small muscles in the arch that help support the plantar fascia.
Custom Orthotics vs. Store-Bought Inserts
If you’re considering arch support inserts, you may not need to spend hundreds on custom-molded orthotics. A review of 20 randomized controlled trials involving roughly 1,800 people found no difference in short-term pain relief between custom orthotics and store-bought versions. Over-the-counter insoles with firm arch support can be a reasonable first step, especially paired with proper footwear.
That said, people with significant structural issues like rigid high arches or severe flat feet may eventually benefit from a custom fit if off-the-shelf options don’t provide relief after a few months.
Other Causes Worth Considering
Not all arch pain is plantar fasciitis. Stress fractures in the small bones of the midfoot can mimic arch pain and tend to develop after sudden spikes in training volume. The pain from a stress fracture is usually pinpointed to a specific spot and gets worse with any weight-bearing activity, not just in the morning or after rest like plantar fasciitis typically does.
Posterior tibial tendon dysfunction, where the tendon supporting your inner arch becomes inflamed or torn, causes pain along the inside of the foot and ankle and can lead to a progressively flattening arch. This is more common in people over 40 and in those who already overpronate. If your arch pain is accompanied by visible flattening of one foot compared to the other, or if you have trouble rising onto your toes on the affected side, this tendon may be the issue.
A higher body weight also accelerates the process. Greater compressive forces on the plantar fascia with each step mean faster collagen breakdown, especially during high-impact activities. Even modest weight changes can shift the balance between tissue damage and recovery.