What are the downsides of running? – Thrive Well Supplements

How running affects your body

If you are asking yourself what are the downsides of running, you are probably already aware of the many upsides. Running can help you lose weight, improve your heart health, and boost your mood. At the same time, it is smart to understand the potential drawbacks so you can avoid problems and keep enjoying your miles for years.

Most of the downsides of running come from doing too much, too soon, or from using the wrong gear. Below, you will find the most common issues, why they happen, and simple ways to lower your risk without giving up your routine.

Common overuse injuries

Overuse injuries are some of the biggest downsides of running. They usually come from repetitive stress on the same tissues without enough recovery.

Runner’s knee and knee pain

Runner’s knee, also called patellofemoral pain syndrome, is one of the most common running injuries. It usually feels like a dull ache around or behind your kneecap, especially when you run, climb stairs, or sit for a long time.

This happens when stress builds up in the cartilage, tendons, and bones around the knee, often after you increase mileage or intensity too quickly (Everyday Health). Weak or imbalanced leg muscles, flat feet, and alignment issues can also play a role (Yale Medicine).

You can lower your risk by:

Building hip and quad strength, especially your glutes and outer hips
Wearing running shoes that match your foot type
Progressing your long runs gradually and avoiding sudden big jumps in distance

Interestingly, recreational running does not appear to wear out healthy knees in the long term. Research suggests it might actually protect against arthritis in the hip and knee (Harvard Health Publishing).

Shin splints and stress fractures

If you feel pain along the inside of your shin when you run, especially after increasing your distance, you might be dealing with shin splints. This is also known as medial tibial stress syndrome and is especially common if you ramp up mileage fast or have flat feet (WebMD).

If you ignore persistent pain and keep training hard, tiny cracks called stress fractures can form in your shin or foot bones. These usually get worse with activity and feel better with rest. Without rest, the crack can deepen and become a more serious injury (WebMD).

To protect your shins and bones:

Introduce new distances or hills slowly
Alternate hard days with easier runs or rest
Do strength work for your calves, ankles, and hips
Stop and see a professional if pain is sharp, localized, or does not improve with rest

Achilles, IT band, and foot problems

Running can also irritate other tissues over time:

Achilles tendinopathy: Pain in the back of your heel from tight calves or sudden jumps in training
IT band friction syndrome: Pain on the outside of your knee or thigh, often linked to weak glutes and wider hips in women (Yale Medicine)
Plantar fasciitis: Heel or arch pain, especially with the first steps in the morning
Muscle strains and ankle sprains: Often from poor warmups, weak stabilizing muscles, or uneven surfaces (WebMD)

You can reduce these risks by adding regular strength training, mobility work, and a brief warmup before each run (Fleet Feet).

When “more miles” becomes a problem

One of the hidden downsides of running is how easy it is to get carried away. You feel fitter, so you add more miles, then a little more, until your body starts to complain.

Sudden distance spikes and injury risk

A large study that followed more than 5,000 adult runners found that big jumps in distance during a single run, not just week-to-week totals, were strongly linked to overuse injuries in the legs (British Journal of Sports Medicine).

Compared with keeping single-run increases at 10 percent or less, the risk of injury went up when you:

Increased a run by more than 10 percent and up to 30 percent
Increased by more than 30 percent
Doubled your distance or more in one session

Over 18 months, about 35 percent of runners reported injuries, and roughly 72 percent of those were overuse injuries that showed up on the same day or within a couple of days of a run (British Journal of Sports Medicine).

For you, this means:

Be careful with “hero” long runs that are far longer than what you usually do
Use your longest recent run as your reference point, not just weekly totals
Respect early warning signs instead of pushing through pain

Overtraining, fatigue, and burnout

Another downside of running is overtraining. This happens when you do not give your body enough time to recover between hard efforts, or when running volume piles on top of life stress, poor sleep, or low calorie intake.

Common signs include:

Slower paces even though you are working harder
Constant fatigue or heavy legs
Irritability or low mood
Getting sick more often (The Health Journals)

Experts note that overtraining is not just about miles. Stress, under eating, nutrient gaps, and lack of sleep all add up and make running harder on your body (The Health Journals).

You can reduce your risk by:

Planning at least one full rest day a week
Building in lighter “recovery weeks” every few weeks of training (Fleet Feet)
Eating enough to support your training and your daily life
Paying attention to mood and energy, not just pace and distance

Heart and long term health concerns

If you want to run to improve your health, you might wonder if there is a point where running becomes too much of a good thing.

Extreme endurance and heart strain

Moderate running is strongly linked to longer life and better heart health. Most studies show that people who run regularly tend to live longer than those who do not (The Health Journals).

At the extreme end, however, very high mileage and repeated marathons can carry some specific risks. Research has raised concerns about:

Abnormal heart rhythms
Temporary heart tissue damage
Hardening of the arteries in some long term, high volume runners (The Health Journals)

There have also been rare cases of runners experiencing heart attacks during events. While these cases are uncommon, they highlight why you should:

Talk with a health professional if you plan to train for frequent marathons
Get routine checkups, especially if you have a family history of heart disease
Pay attention to chest pain, unusual shortness of breath, or dizziness

For most people who run moderately to lose weight and improve health, there is no evidence that more intense training brings extra heart benefits compared with a sensible routine (The Health Journals).

Joints, arthritis, and running

You might worry that running will ruin your knees or speed up arthritis. Current research does not support this for recreational runners.

Studies suggest that:

Recreational runners are less likely to develop hip and knee osteoarthritis than people who do not run at all (University Hospitals)
A survey of about 3,800 Chicago Marathon runners found no link between running history, weekly mileage, and knee or hip osteoarthritis risk (University Hospitals)
Factors like age, body weight, family history, and past injuries have a much stronger impact on your arthritis risk than running does (University Hospitals)

There is a small increase in arthritis risk in elite competitive runners, who train with very high volume and intensity. If you are running for general fitness, this level of training is far beyond what you need (University Hospitals).

To keep your joints comfortable as you age:

Maintain a healthy body weight
Add strength training to support your hips and knees
Mix in low impact activities like cycling or swimming if your joints feel sore (Harvard Health Publishing)
Choose softer surfaces like tracks or dirt trails when possible (Harvard Health Publishing)

Skin, toenails, and other annoyances

Some downsides of running are less serious but still uncomfortable. They can also discourage you if you do not know how to manage them.

Blisters, chafing, and “runner’s itch”

Friction plus sweat is a recipe for skin problems:

Blisters form where your shoes or socks rub against your skin
Chafing happens where skin rubs on skin or clothing, such as the inner thighs, underarms, sports bra lines, or waistband
“Runner’s itch” is an intense itch on your thighs or legs that can show up when blood flow increases to the skin (ASICS)

To protect your skin:

Wear moisture wicking socks and clothing
Use anti chafe balm or petroleum jelly on high friction areas
Avoid cotton, which holds moisture and increases rubbing
Adjust or replace gear that feels rough or tight

Black toenails and foot pain

Distance runners often experience black toenails. This usually happens when your toes repeatedly hit the front of your shoes, causing bleeding under the nail. Shoes that are too small or toenails that are too long increase the risk (Everyday Health).

You might also see “runner’s toenail” on your big toe from microtrauma caused by tight socks or shoes. It is usually harmless, but it is a sign that your footwear setup needs attention (ASICS).

To help your feet:

Get properly fitted running shoes, usually with a thumb’s width of space at the front
Trim your toenails straight across so they are not too long
Replace worn out shoes after roughly 300 to 500 miles to reduce pain in your feet, knees, and back (Fleet Feet)

Breast support and sagging

If you are a woman, running without a supportive sports bra can strain the ligaments that support your breasts. Over time, this may contribute to sagging. The right sports bra helps minimize movement and keeps you more comfortable on every run (ASICS).

Look for:

Wide, soft straps that do not dig into your shoulders
A snug band that stays in place but does not restrict breathing
Moisture wicking fabric to reduce chafing

Tummy trouble and bathroom issues

Another downside of running is how it can affect your digestion and bladder, especially during longer sessions.

Gastrointestinal upset

You might notice:

Cramps or stomach pain
Urgent trips to the bathroom
Nausea during or after a run

These issues are common in runners. They may be triggered by dehydration, stress, and the jostling of your intestines as you run, which can change how your gut functions (Everyday Health).

To keep your stomach calmer:

Avoid heavy, high fiber, or high fat meals in the hours before a run
Experiment with timing your last meal so you feel neither stuffed nor starving
Sip water regularly, but not in huge gulps right before you start
Test any sports drinks or gels during shorter runs first before race day

Overactive bladder and urgency

You might find that you suddenly need to use the bathroom shortly after starting your run. Increased blood flow to your kidneys boosts urine production, and dehydration can also affect bladder sensitivity (Everyday Health).

To manage this:

Go to the bathroom right before heading out
Plan routes with possible restroom stops if you run longer distances
Keep an eye on your fluid intake throughout the day instead of chugging water right before your run

If urgency or leakage is frequent or severe, talk with a health professional. Pelvic floor exercises and tailored advice can help.

Muscle loss and body composition

If you are running mainly to lose weight, it helps to know how running can change your body composition over time.

When you run a lot and do not strength train or eat enough protein, your body may start to break down some muscle as well as fat. This is because your body is trying to shed any “extra” weight that could slow you down, including muscle mass (ASICS).

You can keep more lean muscle while still enjoying the weight loss benefits of running by:

Eating enough protein throughout your day
Adding strength training 2 to 3 times a week
Including short high intensity intervals instead of only long, slow runs when you are ready for them (ASICS)

This approach supports a stronger, more balanced body and may help your running performance as well.

Training “by feel” vs structured plans

Some runners like to ignore heart rate zones, paces, and detailed training plans. You might simply go out and run by feel, especially if your main goal is enjoyment or stress relief.

A discussion among marathon runners showed that some people have success training this way, even for long races, without obsessing over metrics or fueling schedules (Reddit r/Marathon_Training).

However, there can be downsides if you take this too far:

You may run too hard on easy days, which increases injury risk
You might under fuel on long runs, which affects your energy and recovery (Reddit r/Marathon_Training)
Without any structure, it can be harder to progress safely toward longer races

You do not have to track every metric, but borrowing a few ideas from structured training plans can help. For example, you might:

Keep most runs easy and conversational
Add only one or two harder or longer sessions each week
Plan when you will eat or drink during runs longer than about an hour

This lets you keep the joy of running by feel while still protecting your body.

Mistakes that make running harder

Many of the downsides of running are made worse by a few common habits. Adjusting these can make a big difference in how you feel.

Skipping warmups and strength work

If you start every run cold, your muscles and joints have to absorb impact before they are ready. Over time, that can add up to overuse injuries like strains and tendon problems.

Even a short warmup helps. Try:

A few minutes of brisk walking
Leg swings, hip circles, and light lunges
Simple activation moves like glute bridges or calf raises

Adding strength training a couple of times a week builds resilience in areas that often get overloaded, such as the hips, knees, ankles, and core (Fleet Feet).

Ignoring pain signals

One important lesson for runners is learning the difference between normal discomfort and injury pain.

Mild soreness that eases as you warm up and does not get worse with each run is often just your body adapting. Sharp, localized, or increasing pain that changes your stride is a warning sign.

Experts advise that if pain is persistent or severe, you should not push through. Stop, rest, and seek professional help if needed, instead of waiting for a small issue to turn into a major injury (Fleet Feet).

Running in the wrong shoes

Old or poorly fitted shoes are a quiet but significant downside of running. They can lead to:

Foot, knee, and back pain
Blisters and calluses
Cramps and aches that make you dread runs

Most running shoes last about 300 to 500 miles. After that, cushioning and support break down (Fleet Feet). If your shoes are visibly worn, feel flat, or cause new aches, it may be time to replace them.

A simple way to check: write the purchase date inside the tongue or track shoe mileage in an app so you are not guessing.

Balancing the pros and cons

Understanding what are the downsides of running does not mean you should avoid running altogether. Instead, it helps you make smarter choices so you can keep enjoying the many benefits, including weight loss, better cardiovascular health, and stress relief.

You can tip the balance in your favor by:

Increasing mileage gradually and avoiding big single session spikes
Mixing in rest days, lighter weeks, and low impact cross training
Wearing supportive shoes and gear that fit you well
Adding strength work and short warmups to protect joints and tendons
Listening to your body and adjusting when something feels off

If you are just starting out, pick one small change to focus on, such as replacing worn shoes or adding a 5 minute warmup. Then, build from there. Over time, those thoughtful adjustments can help you enjoy the upsides of running while keeping the downsides in check.