Flat Feet and High Arches: Different Effects on Running and Cycling, and General Principles for Insole Adjustments

Medical Disclaimer (Please Read First)

This article is a general educational overview of sports-related knowledge and does not constitute a medical diagnosis, nor does it replace an evaluation of your individual foot structure by a foot and ankle surgeon, rehabilitation physician, or qualified foot orthotist (Podiatrist, Pedorthist, or related professional). Determining arch type, whether custom insoles are needed, and the design details of such insoles all require an actual foot examination, gait analysis, or pressure testing for accurate assessment. What this article provides is only directional, general principles and cannot replace professional evaluation and custom recommendations. If you have chronic foot pain, recurrent ankle sports injuries, or obvious foot deformities, please seek medical evaluation first. A list of warning signs requiring medical attention is provided at the end of the article.

Many people go their entire lives without paying much attention to the height of their foot arches—until a bout of recurring plantar fasciitis, or knee pain on the outside of the knee from cycling, prompts them to seriously investigate whether they have flat feet or high arches. This article aims to focus on a frequently overlooked angle: the logic of how flat feet and high arches affect “running” versus “cycling” is actually quite different. Many people are accustomed to discussing “foot care” as a single topic, but in reality, these two sports place very different demands on the feet, and it is worth understanding them separately.

Basic Functions and Classification of Foot Arch Types

The foot arch is a structure formed by the bones, ligaments, and fascia of the foot. Its primary functions are to provide shock absorption, force transmission, and propulsion efficiency during weight-bearing, walking, and running. Arch types can be broadly divided into three categories: normal arch, flat foot (collapsed or low arch), and high arch (elevated arch, also known as pes cavus). This is a rough classification; in reality, arch height exists on a continuous spectrum, and other factors may also be present (such as whether the foot overpronates or oversupinates under load). Simply using a “flat or high arch” dichotomy is sometimes insufficient to fully describe an individual’s foot biomechanical profile.

Flat foot refers to a condition where the arch is noticeably low or nearly absent under weight-bearing conditions, with collapse of the medial longitudinal arch. Flat feet can be divided into flexible (where the arch is still visible when non-weight-bearing and the foot is suspended, collapsing only under load) and rigid (where the arch is not apparent regardless of weight-bearing) types. The management approaches for these two types differ, which is why determining flat feet cannot rely solely on the simple visual observation of “whether the entire sole touches the ground when standing”—professional examination is needed to distinguish the type. When bearing weight and walking, flat feet often show a tendency toward more pronounced inward rotation (overpronation). This biomechanical characteristic is key to understanding how flat feet affect athletic performance.

High arch is the opposite: the arch is noticeably elevated, the contact area between the sole and the ground is smaller, and the foot’s overall shock-absorbing capacity is relatively poorer. Additionally, high-arched feet tend to be stiffer, with less pronation under load, and may even exhibit oversupination—where the foot rolls toward the outside under weight-bearing—further diminishing shock absorption.

Impact on Running: Amplification or Buffering of Repeated Ground-Contact Impact

Running is an activity that requires the foot to repeatedly absorb ground-contact impact. With each foot strike, the foot must absorb the ground reaction force generated by body weight plus movement. During this process, the foot arch plays a critical shock-absorbing role, which is why arch type has a relatively direct and obvious impact on running.

Common effects of flat feet on running: Due to arch collapse and a tendency toward overpronation under load, flat-footed runners tend to experience greater torque on the medial side of the foot during the impact absorption phase. If this force is not adequately buffered or controlled, it can travel up the lower-limb kinetic chain, increasing load on the medial tibia, medial knee, and other areas. Clinically, flat feet are considered to have a certain biomechanical association with several common running-related injuries (such as medial tibial stress syndrome, plantar fasciitis, and certain patterns of knee pain). However, this does not mean all flat-footed runners will inevitably be injured—many people with flat feet go through their entire athletic careers without such injuries. Biomechanical characteristics are just one of many contributing factors and must be considered alongside training load management, muscular strength, running technique, and other variables.

Common effects of high arches on running: Because the sole’s shock-absorbing capacity is poorer and the foot is stiffer, high-arched runners find it harder for the foot itself to absorb ground-contact impact, allowing more impact force to be transmitted directly to the lower leg, knee, and even hip joint. As a result, high-arched runners are relatively more likely to feel pronounced vibration upon foot strike. Over the long term, high arches are also considered to have a certain correlation with specific sports injury patterns such as stress fractures and iliotibial band syndrome. Additionally, because the foot’s contact area with the ground is smaller, high-arched runners may have relatively poorer stability and balance on uneven surfaces, so the risk of ankle sprains warrants attention.

Impact on Cycling: Pressure Distribution at the Cleat Interface

Although cycling also relies on the feet, the way the foot interacts with the ground—or rather, with the pedal—is completely different from running. During cycling, the foot does not repeatedly absorb ground-contact impact; instead, it transmits pedaling force through the relatively fixed interface of the cycling shoe and cleat. Therefore, the logic of how arch type affects cycling differs from running.

Common effects of flat feet on cycling: If the arch collapses and the foot tends to overpronate inside the cycling shoe while riding, pedaling force may not be evenly transmitted through the sole to the cleat. After prolonged riding, some flat-footed cyclists report discomfort on the medial side of the arch, the sole, or the medial knee. This is related to uneven force distribution during the pedal stroke and changes in lower-limb alignment caused by foot pronation.

Common effects of high arches on cycling: Because the arch is elevated, the contact area between the sole and the shoe’s footbed is smaller, and pressure is concentrated on the narrower regions on either side of the arch. After prolonged riding, some high-arched cyclists are prone to discomfort or even numbness at localized pressure points around the midfoot or near the metatarsal heads. This is related to insufficient support to distribute pressure between the sole and the insole.

It is worth noting that because the foot is relatively fixed to the cleat during cycling—unlike running, which involves repeated ground-contact impact—the tolerance for arch type variations is, to some extent, more forgiving than in running. This is also why, as mentioned in the earlier article on degenerative joint disease, cycling is often regarded as a relatively joint-friendly alternative exercise for the lower limbs. However, this does not mean arch abnormalities have no impact on cycling at all; rather, the mechanism and the area of discomfort differ from running. During prolonged rides—especially challenges like Wuling with long climbs that require maintaining a fixed pedaling posture for hours—localized foot pressure discomfort can still accumulate and become noticeable over time.

Rough Comparison of the Effects of Flat Feet and High Arches on Running and Cycling

General Principles for Insoles and Equipment Adjustment

The core function of insoles (whether running shoe insoles or cycling shoe inserts) is to provide appropriate support and pressure distribution between the foot and the footwear, helping the foot maintain a more ideal mechanical alignment during activity. The following are general considerations; actual selection should still be strongly based on professional assessment (gait analysis, pressure testing) rather than self-guessing:

Insole adjustment direction for flat feet: Consideration is typically given to providing moderate support on the medial side of the arch to help reduce excessive pronation during weight-bearing. The common “stability” or “support” running shoes and insoles with built-in arch support on the market are mostly designed for this mechanical need. However, stronger support is not necessarily better—over-correction can also cause discomfort in other areas. This is why custom insoles or professional shoe selection recommendations require actual testing rather than simply applying theory.

Insole adjustment direction for high arches: Consideration is typically given to increasing overall cushioning and shock absorption, as well as providing moderate support on both sides of the arch, allowing pressure to be distributed more evenly across a larger area of the sole rather than concentrating on a few small contact points. Cushioned running shoes and insoles with sufficient shock-absorbing materials are common shoe selection directions for the high-arch population.

Adjustment direction for cycling shoe insoles: Whether for flat feet or high arches, the support provided by stock cycling shoe insoles is usually quite basic. If foot discomfort persists during long rides, it is worth consulting a professional bike fitter or sports medicine professional to assess whether replacing the insoles with cycling-specific ones that offer arch support or pressure distribution is necessary. At the same time, cleat angle, lace or Velcro strap tightness should also be reviewed, as these can indirectly affect the distribution of forces on the foot during pedaling.

Gradual adaptation to new insoles or new shoes: Whether adjusting running shoes or cycling shoes, any new form of support or cushioning requires an adaptation period for the body. It is not advisable to suddenly switch to brand-new insoles or shoes right before a long-distance race or an important training session. This follows the same principle as the “no experimenting on race day” rule mentioned earlier regarding nutrition—new equipment should first be tested and adapted to during less important training sessions.

How to Initially Observe Which Arch Type You Might Have (For Reference Only, Not a Diagnosis)

Before seeking professional assessment, sports enthusiasts can use a few simple self-observation methods to gain a preliminary directional understanding of their arch type. However, it is important to understand that these are only rough references and cannot replace professional dynamic gait analysis or pressure testing:

Wet footprint test: Wet your bare feet and step onto a dark-colored cardboard or surface, then observe the shape of the footprint. For those with normal arches, the inner side of the footprint will show a clear inward curve; for those with flat feet, the inner curve is indistinct or nearly the entire sole is imprinted; for those with high arches, the inner side of the footprint will be very narrow, or the midfoot section may be almost completely disconnected. The limitation of this test is that it only reflects the state during static standing and cannot show the actual mechanical behavior of the arch under dynamic weight-bearing during running or cycling. This is why professional assessments typically combine treadmill dynamic video analysis or pressure-sensing plates for a more complete evaluation.

Observation of old shoe wear patterns: Examining the wear patterns on the soles of running shoes you have worn for a period of time can also provide some clues. Those who over-pronate (commonly seen in flat feet) often show more obvious wear on the medial side of the sole, especially the medial forefoot; those with a supination tendency (commonly seen in high arches) typically show more concentrated wear on the lateral side of the sole. This method is likewise only a rough reference—the shoe’s design, surface type, and individual running habits all affect wear patterns, so conclusions cannot be drawn from sole wear alone.

Observation of knee tracking during pedaling: When riding on a stationary trainer, have someone observe from directly in front or behind to see whether your knees exhibit obvious inward collapse or outward swing during a full pedal revolution. Such abnormal tracking can sometimes be related to arch type and lower-limb mechanical alignment. If obvious abnormalities are present, a full assessment through professional bike fitting is worth pursuing.

General Strength and Stretching Directions for Different Arch Types

Beyond insole and equipment adjustments, strength training for the foot and surrounding calf muscles is also a direction frequently mentioned in sports medicine as helpful for improving arch-related discomfort. However, the specific angles, loads, and suitability of exercises should still be designed by a physical therapist based on individual conditions. The following provides only a conceptual overview:

Common training directions for the flat-foot population: Focus on strengthening the supporting structures on the medial side of the arch, such as training the intrinsic muscles of the foot (e.g., towel-grip exercises, a movement concept that activates the small muscles of the foot), as well as strength training for the medial calf muscles and the tibialis posterior. The goal is to enhance the foot’s active ability to control the degree of pronation, rather than relying solely on passive support from insoles.

Common training directions for the high-arch population: Focus on improving the flexibility and shock-absorbing capacity of the ankle and calf, such as stretching the posterior calf muscles and the plantar fascia, as well as stability training for the ankle at various angles (e.g., single-leg balance training). The goal is to compensate for the arch’s inherent lack of shock absorption while also reducing the risk of ankle sprains.

These training directions are presented conceptually. The actual exercise selection, repetitions, and intensity all need to be adjusted according to individual foot conditions, current symptoms, and athletic goals. Recklessly attempting “corrective exercises” found online without proper guidance—if the angles or intensity are inappropriate—may actually cause new discomfort. This is why it is recommended to perform these under professional supervision, especially for those who already have noticeable symptoms.

Clarifying Common Misconceptions

Myth 1: “Flat feet or high arches absolutely require corrective insoles, otherwise you will definitely get injured.” Arch type is only one factor affecting the risk of sports injuries. Training load management, muscular condition, running or pedaling technique, and ground or road conditions must also be considered. Many athletes with abnormal arches can maintain good performance through proper training load management and strength training without necessarily needing custom insoles.

Myth 2: “Insoles can ‘correct’ the bony structure of the arch.” For adults, the bony structure of the arch is already fully formed. The function of insoles is primarily to provide support during activity, alter pressure distribution, and assist mechanical alignment—not to actually change the bony structure itself. This concept is often exaggerated in marketing, and the actual effects should be viewed rationally.

Myth 3: “Measuring a footprint image online can accurately determine arch type and help you choose the right insole.” The simple wet footprint test can serve as a rough initial reference, but a complete assessment of arch type typically also requires consideration of dynamic gait and mechanical behavior under weight-bearing, which static footprints cannot fully capture. If you have long-term related discomfort, a more complete assessment through professional gait analysis or pressure testing is recommended.

Myth 4: “People with abnormal arches are not suited for cycling or running and should switch sports.” As mentioned earlier, arch type affects different sports through different mechanisms. Most people with abnormal arches can continue participating in road running or cycling with appropriate equipment adjustments and training management—there is no need to give up the sports they love.

Practical Reminders for Taiwan’s Local Training Context

Taiwan’s road running and cycling route environments present some local considerations worth noting for athletes with abnormal arches. Riverside bike paths and urban roads are mostly flat and even, making them relatively friendly for runners with abnormal arches and a suitable starting point for gradually building mileage while observing how your feet respond. In contrast, if your goal is to participate in long-distance events such as the Taipei Marathon, Wan Jin Shi Marathon, or Tanaka Marathon, the asphalt surfaces, bridge elevation changes, and prolonged repeated ground contact in the middle sections of the course will cause arch-related discomfort to gradually surface as mileage accumulates. It is advisable to use longer training runs early in the season to observe how your feet actually respond near race distance, rather than facing that load for the first time on race day.

For cyclists planning to tackle long climbing routes such as Wuling, Fengguizui, the Beiyi Highway, or the Yangjin P-shaped mountain road, maintaining a fixed pedaling position for several hours means that any existing pressure points in the cycling shoes will typically become more pronounced as riding time extends. Before formally challenging such long climbs, it is advisable to schedule longer training rides (for example, two hours or more) to actually test whether your cycling shoes, insoles, and cleat settings cause discomfort under prolonged load, and to make adjustments early—rather than discovering the problem mid-climb with no way out.

Medical Consultation and Professional Evaluation Warning Signs

If any of the following situations occur, it is recommended to seek evaluation from a foot and ankle surgeon, rehabilitation physician, or a qualified foot orthotics professional, rather than relying solely on self-assessment or online information when purchasing insoles:

• Foot or ankle pain persists for more than one to two weeks without relief, or the pain gradually intensifies.
• Recurrent plantar fasciitis, suspected symptoms of stress fractures (localized point tenderness at a fixed spot, swelling), Achilles tendon pain, or other sports injuries.
• Obvious deformities of the foot, noticeable changes in appearance compared to the past, or accompanying neurological symptoms such as numbness or tingling.
• Abnormal foot arches are observed in children or adolescents. Pediatric foot arch development follows a specific timeline and requires distinct evaluation methods; adult assessment logic should not be directly applied. Early evaluation by a pediatric orthopedic or rehabilitation specialist is recommended.
• Discomfort does not improve or even worsens after switching to different shoes or insoles.
• Coexisting chronic conditions such as diabetes that may affect foot sensation and circulation require more cautious foot care. Any foot discomfort should prompt early medical consultation to avoid delayed treatment due to reduced sensation.

Conclusion and Action Checklist

Flat feet and high arches affect running and cycling through different mechanisms. Understanding this difference helps sports enthusiasts more accurately identify which part of the kinetic chain their discomfort may originate from, rather than treating “foot arch care” as a single, generalized issue. Here is an action checklist you can review immediately:

• [ ] Identify whether your foot arch type is flat feet, high arches, or somewhere in between. If necessary, confirm through professional gait analysis rather than relying only on visual observation.
• [ ] Understand separately how foot arch type affects road running (impact cushioning upon ground contact) versus cycling (pedaling pressure distribution).
• [ ] If related discomfort persists, prioritize custom insoles after professional evaluation rather than purchasing corrective insoles online on your own.
• [ ] Always adapt to new insoles or new shoes gradually during training; never switch right before an important race.
• [ ] Pay attention to often-overlooked details such as cycling shoe insoles and cleat angles, and consult a professional Bike Fitting service when necessary.
• [ ] Watch for the medical warning signs listed in this article, especially for children’s foot arch development or those with chronic conditions; seek professional evaluation early.

The foot arch is just one link in the lower-limb kinetic chain. Considering it within the broader context of overall training management, muscular condition, and equipment adjustments will contribute more to the long-term health of your athletic career than fixating solely on the label of “flat feet or high arches.”

Related Reading

• Road Running Shoe Buying Guide: Correct Matching of Foot Types (Flat, Normal, High Arch) with Shoe Models
• Running Foot Arch Morphology and Plantar Pressure Distribution: Kinetic Comparison of High Arches vs. Flat Feet
• Running Insoles and Arch Support: How to Choose the Right Insoles for Yourself
• Your Feet Are the Foundation of Your Sport: A Complete Coach’s Guide from Foot Function, Flat Feet and High Arches to Insoles