What are the downsides of running?

Running is a simple way to lose weight, clear your head, and improve your health. Still, if you have ever wondered, “what are the downsides of running?”, you are not alone. Like any workout, running has trade-offs. Understanding them helps you keep the benefits of running while lowering your risk of injury, burnout, and frustration.

Below, you will find the most common downsides of running and practical ways to work around them so you can keep moving safely.

Injury risk from overuse

One of the biggest downsides of running is its high injury rate. Experts estimate that at least half of regular runners get injured each year, and most of those injuries come from overuse rather than falls or accidents (Yale Medicine).

Common overuse injuries

Overuse injuries usually build up gradually. You might notice a mild ache at first, then sharper pain if you keep pushing:

• Runner’s knee
  Pain around or behind your kneecap, especially when you run, squat, or go down stairs. This is often linked to muscle imbalances, flat feet, or alignment issues (Yale Medicine, WebMD).

• Shin splints
  Tenderness or pain along your shin bone, especially when you increase distance or frequency too quickly. People with flat feet are at higher risk (WebMD).

• Stress fractures
  Tiny cracks in your bones, often in your shins or feet, caused by repeated pounding before your body adapts. The pain improves with rest and worsens with activity. Continuing to run can turn a small crack into a more serious break (WebMD, Yale Medicine).

• Achilles tendinopathy and plantar fasciitis
  Achy or sharp pain in your heel cord or the bottom of your foot, often worse with the first steps in the morning and after runs (WebMD).

• IT band syndrome
  Pain on the outside of your knee that worsens as you run. This is especially common in women because wider hips can stress the IT band, often linked to weak glute muscles (Yale Medicine).

How training spikes increase injury risk

How quickly you increase your runs matters. A large study of more than 5,000 adult runners found that when you suddenly spike your distance in a single run by more than 10 percent compared with your longest recent run, your risk of overuse injury climbs significantly (British Journal of Sports Medicine).

In that study:

• Small distance spikes of more than 10 to 30 percent increased injury risk
• Larger spikes of more than 100 percent nearly doubled it

Around 35 percent of runners in the study reported injuries, most of them overuse injuries that showed up on the same day or within a couple of days after a run (British Journal of Sports Medicine).

Interestingly, traditional metrics like week-to-week mileage changes and the acute to chronic workload ratio did not predict injuries well in this group, which suggests your single hardest or longest run may be more important than your weekly totals (British Journal of Sports Medicine).

Ways to lower your injury risk

You cannot reduce your injury risk to zero, but you can tilt the odds in your favor.

• Increase distance gradually
  Try not to exceed about 10 percent more than your longest recent single run in one go, especially if you are newer or coming back from a break (British Journal of Sports Medicine).

• Strength train regularly
  Focus on glutes, hips, quads, hamstrings, and calves. Strong supporting muscles help protect your joints and tendons (Yale Medicine, Fleet Feet).

• Warm up before each run
  Simple activation moves like leg swings, lunges, and glute bridges prepare your muscles and joints for repetitive impact (Fleet Feet).

• Take pain seriously
  Normal workout soreness usually improves as you warm up. Sharp pain, swelling, or pain that worsens with every run is a red flag. Ignoring real pain is a shortcut to longer recovery time (Fleet Feet).

Joint health and your knees

If you want to lose weight with running, you might worry that all that pounding will destroy your knees. Surprisingly, for most people, this is not one of the major downsides of running.

Research shows that recreational runners actually have a lower risk of hip and knee arthritis compared with people who do not run at all (Harvard Health Publishing, University Hospitals).

What the research says about knees

According to Harvard Health and University Hospitals:

• Running does not speed up wear and tear on knee joints
• Cartilage in your knees may even be stimulated to stay healthy by regular running
• A large survey of roughly 3,800 marathon runners found no link between weekly running mileage or years of running and higher risk of hip or knee osteoarthritis (University Hospitals)

Elite competitive runners who log very high volumes may have a slightly higher rate of hip and knee arthritis than people who are sedentary, but for recreational runners, factors like family history, age, body weight, and prior injuries matter more than running itself (University Hospitals).

Protecting your joints as you run

You can take simple steps to make running easier on your knees and hips:

• Maintain a healthy body weight so you are not putting unnecessary load on your joints
• Rotate in lower impact activities like cycling, swimming, or yoga, especially if you have early arthritis or joint soreness (Harvard Health Publishing)
• Run on softer surfaces when possible, such as dirt trails or school tracks, which can feel better than concrete (Harvard Health Publishing)

If you already have arthritis, a physical therapist or sports doctor can help you find the right distance, pace, and surfaces for your joints.

Everyday discomforts and annoyances

Not all downsides of running are serious injuries. Many are simply annoying, but they can still make your runs miserable if you are not prepared.

Skin issues: chafing, blisters, and “runner’s itch”

Repetitive motion, sweat, and clothing can irritate your skin in surprising ways:

• Chafing
  Repeated friction can irritate skin in your inner thighs, underarms, sports bra line, and more. Men often struggle with nipple chafing. Women may notice chafing along the bikini line. Heat and moisture make it worse (Everyday Health, ASICS).

• Blisters
  Friction between your feet, socks, and shoes can cause fluid-filled blisters, especially if your shoes are new, too tight, or too loose (WebMD).

• Runner’s itch
  Itchy thighs or legs when you start running may stem from increased blood flow and nerve stimulation, and it often fades as your body adjusts (ASICS).

You can reduce these problems by:

• Wearing moisture wicking fabrics instead of cotton
• Using anti chafe balms or petroleum jelly on problem areas
• Choosing socks with smooth seams and good fit
• Breaking in new shoes gradually

Foot problems like black toenails

If you increase your distance, you may discover one of the stranger downsides of running: black toenails. These happen when your toes repeatedly hit the front of your shoes, which causes bruising and bleeding under the nail.

Distance runners are especially prone to this if:

• Shoes are too small or too tight
• Toenails are not trimmed short
• Socks are too thick for the shoe size (Everyday Health, ASICS)

A single black toenail is usually harmless, just unattractive. Repeated bruising is a nudge to get properly fitted shoes and keep your nails trimmed.

Clothing and support issues

What you wear while running can make a big difference in comfort:

• Poor breast support
  For women, running without a well fitted sports bra can contribute to discomfort and potential sagging over time as breast tissue is repeatedly pulled by gravity (ASICS).

• Weather related problems
  Inadequate layers, lack of sun protection, or overdressing in heat can lead to temperature related issues like overheating, dehydration, or in extreme cases, heat illness or hypothermia (WebMD).

Whenever possible, choose gear that fits well, keeps you dry, and matches the weather conditions.

Digestive and bladder problems

If you have ever had to sprint for a bathroom mid run, you know that your gut and bladder are part of the “what are the downsides of running” conversation.

Tummy trouble while running

Running increases movement in your intestines, which can trigger:

• Cramping
• Bloating
• Urgent bathroom trips

Dehydration, stress, and jostling of your digestive system can all play a role (Everyday Health). Some runners also find that eating heavy or high fiber meals too close to a run leads to more trouble.

A few strategies may help:

• Leave a gap of 2 to 3 hours between a large meal and your run
• Test simple, lower fat, lower fiber snacks before long runs
• Sip water regularly instead of chugging right before you start

Overactive bladder during runs

You might also notice that you suddenly feel like you need to pee soon after you start running. The increased blood flow during exercise can speed up urine production. Dehydration can make your bladder more sensitive too (Everyday Health).

If this happens often, consider:

• Using the bathroom right before you head out
• Planning routes near public restrooms
• Spacing your fluids throughout the day instead of front loading right before a run

If bladder urgency is frequent or severe, especially if it affects your daily life, check in with a doctor. Pelvic floor therapists can also help with specific exercises.

Heart health and extreme running

Overall, running is linked with a longer life and better heart health. Most people do not need to worry that moderate running will harm their heart (The Health Journals). The potential downside shows up primarily with excessive training, especially at the marathon or ultra marathon level.

Possible heart related downsides at high volumes

Some research suggests that very frequent, long distance racing and extreme training loads may:

• Increase the risk of abnormal heart rhythms
• Cause small amounts of heart tissue damage
• Promote hardening of arteries in some long term, high volume runners (The Health Journals)

There have been rare cases of runners dying of heart attacks during races, usually in events lasting several hours (The Health Journals).

At the same time, studies generally show that people who run have lower overall mortality. Moderate runners do not appear to gain extra heart benefits by pushing much longer or harder, which suggests that “more” is not always “better” for your heart (The Health Journals).

Balancing ambition and safety

If you enjoy long distance running or marathons, you can still protect your heart by:

• Talking with your doctor, especially if you have a family history of heart disease or any concerning symptoms
• Building your long runs gradually rather than jumping into extreme distances
• Monitoring for warning signs like chest pain, unusual shortness of breath, palpitations, or feeling faint

For weight loss and health, you usually do not need marathon level mileage. A mix of moderate runs, intervals, and cross training can provide excellent cardiovascular benefits with lower risk.

Overtraining, fatigue, and burnout

Another downside of running is how easy it is to overdo it once you catch the running bug. More miles can feel like progress, but your body and mind may say otherwise.

Signs of overtraining

Overtraining happens when the stress of your workouts outweighs your recovery. This is influenced by factors like:

• Life stress
• Lack of sleep
• Under eating or poor nutrition
• Illness
• Nutrient deficiencies (The Health Journals)

When you cross that line, you may notice:

• Constant fatigue
• Sluggish or slower mile times even when you try harder
• More frequent colds or illnesses
• Irritability or low mood
• Trouble sleeping or unrestful sleep (The Health Journals, Fleet Feet)

You can also burn out mentally. If every run becomes a test or a comparison against your watch, it is easy to lose the joy that got you started.

How intensity and metrics can backfire

If you always run hard or chase new personal bests, you never give your body time to adapt. A running coach quoted by Fleet Feet notes that pushing intensity too often without enough “easy” days can create a negative feedback loop: you feel tired, you run slower, you get discouraged, and you push harder anyway, which only worsens fatigue (Fleet Feet).

On the other hand, some runners go in the opposite direction and ignore structured training entirely. For example, a runner on Reddit described running marathons from 2018 to 2023 without tracking heart rate, fueling, or detailed training plans. They felt this simplified approach reduced stress and increased enjoyment, but they also wondered if they were missing out on performance and long term injury prevention benefits (Reddit r/Marathon_Training).

This highlights a practical tension:

• Too much focus on metrics can be demotivating
• No structure at all may leave you underfueled, under recovered, and more vulnerable to overuse injuries

Keeping running sustainable

To enjoy the benefits of running over the long term:

• Build in easy days and rest days
  Your body needs downtime to repair the muscles and connective tissues that are stressed by running. Skipping rest increases the risk of overuse injuries (Fleet Feet).

• Use structure without obsession
  A simple plan with a mix of easy runs, one harder effort per week, and rest days usually works well. You do not have to track every metric to see progress.

• Fuel and hydrate properly
  Heading into long runs without a fueling plan can leave you under energized and may slow recovery. Even if you decide not to micromanage gels and drinks, having a general rhythm of carbs and fluids during long efforts can protect both performance and health (Reddit r/Marathon_Training).

• Pay attention to overall life load
  Busy weeks, poor sleep, and high stress all act like additional training. On those days, ease back on mileage or intensity.

Running related changes in body composition

If your goal is weight loss, you may expect running to burn fat and reveal muscle. That can happen, but there is a potential downside if you are not careful with your strength work and nutrition.

Muscle loss from high mileage

Your body is efficient. When you do a lot of steady state running, it may start shedding anything it considers extra weight, including some muscle tissue. Over time, this can lead to reduced muscle mass, which might not be what you want if you care about strength, shape, or long term metabolism (ASICS).

How to protect your muscle

You can still use running as a primary tool for weight loss and fitness while keeping your muscles by:

• Eating enough protein
  Aim to include a solid protein source with each meal and snack, especially after runs.

• Adding strength training 2 to 3 times per week
  Squats, deadlifts, lunges, rows, and pushups help signal your body to keep, and even build, muscle despite your running volume.

• Mixing in intervals or hill sprints
  Higher intensity sessions encourage your body to maintain power and muscle, not just endurance (ASICS).

This balanced approach supports fat loss, protects lean mass, and tends to help you feel stronger and more stable on your runs.

Shoe choices and gear mistakes

Another practical downside of running is that it is easy to sabotage your comfort and progress with the wrong gear, especially shoes.

Problems caused by wrong or worn out shoes

If your shoes are too small, too big, or simply past their prime, you are more likely to experience:

• Foot pain
• Knee and back discomfort
• Cramping and aches after runs
• Black or bruised toenails

Running shoes generally last about 300 to 500 miles. After that, cushioning and support break down, which means your joints and muscles absorb more impact (Fleet Feet).

A runner in Miami described significant discomfort from running in the wrong shoes, which cleared up once they were properly fitted and switched to different footwear (Fleet Feet).

Getting your gear right

You do not need expensive equipment, but a few smart choices go a long way:

• Visit a running shop for a shoe fitting if possible
• Replace shoes based on mileage or when they start to feel “flat”
• Choose socks that wick moisture and fit your foot
• Adjust clothing for the weather, paying attention to sun, wind, and cold

Comfortable gear will not fix training mistakes, but it removes one more barrier between you and a consistent routine.

How to enjoy the benefits while limiting the downsides

Understanding what the downsides of running are does not mean you should avoid running altogether. For most people, running is still a powerful, low cost way to lose weight, improve heart health, and boost mood.

The key is to approach it with respect for your body:

• Ease into mileage and avoid big single session spikes
• Mix running with strength training and other activities
• Take rest and recovery as seriously as your workouts
• Address small pains and annoyances before they turn into bigger problems
• Choose gear and nutrition that support your goals

If you listen to your body and adjust as you go, you can keep running as a sustainable, enjoyable part of your health journey rather than a source of ongoing aches and setbacks.