Why Do My Thighs Hurt When Cycling: A doctor’s advice on managing leg pain


Many new cyclists suffer from thigh pain, but why is this? And why does thigh pain seem to last for such a long time, even after you’ve finished your ride? As a doctor and cyclist, I thought I would be well placed to take a closer look into what causes thigh pain while cycling.

Thigh pain while cycling is caused by the build-up of lactic acid, this causes the muscle to become more acidic and results in pain. In the 48 to 72 hours following your ride, ongoing pain is often the result of delayed onset muscle soreness which is caused by multiple micro-tears to the muscle and nerves.

So, we’ve established at a very superficial level the causes of the pain in your thigh from cycling, as well as why it can hurt in the few days after a cycle. But how does all this happen? In the rest of this article, I’ll take a closer look into why your thighs hurt as you are cycling, then why they hurt after your cycle, and finally take a look at a few ways you can help the pain, or even prevent it in the first place.

Why do my thighs hurt when cycling?

First things first. As with any sports-related pain or injury, it’s important to seek formal advice from a medical professional. While I am a qualified doctor, it is important for me to remind you that I have not been able to properly assess you personally before giving this advice. This page has generic advice and if you are having any symptoms such as pain or numbness then you should ensure you are seeking formal medical attention.

This article is a resource that can help you to reduce your thigh pain once other causes of pain (not being caused by your cycling), have been excluded. Some causes of pain can be serious and should be discussed with a medical professional urgently.

When looking at the ache you get in your thighs as you cycle, it is easier to split the answer into the “normal” pain that comes from cycling or the “abnormal” pain you might experience.

“Normal” (expected) pain

As you exercise any of your muscle areas, there is a normal or expected level of burning you can expect.

As you work your muscles, multiple chemical reactions take place in the muscles themselves to create energy. This energy is used to relax and contract the muscles as you exercise, which is what moves your legs and the pedals around.

Initially, your body uses a process called aerobic respiration to create this energy. Aerobic respiration is good at making a constant, but slow rate of energy, for example when you are cycling slowly or walking.

If you increase the intensity of the activity you are doing, for example when you are trying to cycle faster or uphill, your body has to use a different process to make additional energy. This is called anaerobic respiration. Anaerobic respiration is great at making lots of energy fast but also creates so byproducts, one of which is called lactic acid.

The burning pain you experience while exercising intensely is caused by the build-up of this lactic acid in the muscle itself,. This lactic acid makes the area more acidic and causes you pain. Don’t worry, this is a completely normal process and it won’t do you harm in the long term.

The main muscles your body uses for cycling are located in the thigh and buttocks and so it is not surprising that the “burn” you experience while cycling is felt mostly in these areas.

If you want to take a more detailed look into which muscles are used when cycling, take a look at my article here.

“Abnormal” (unexpected) pain

It can be hard to tell what is normal and what is abnormal as you start out on your cycling journey. Most unexpected pains during a cycle are caused by an injury to a tendon, muscle, or joint.

Injuries while cycling can occur in many ways, however, the most common result from either a single excessively stressful motion, a repetitive strain injury, or a sustained period of intense work. All of these can result in tears, strains, or twists.

Often, these types of injuries can be differentiated from the normal pain you experience as you cycle as they are out of proportion to your normal levels of pain and are more sudden onset

The most common injuries that can cause pain in your thigh as a result of cycling include a strain to your iliotibial band, piriformis syndrome, quadriceps tendinitis, or greater trochanteric pain syndrome.

ConditionTypical location of pain
Iliotibial band syndromeOutside of the knee
Piriformis SyndromeButtocks and down the leg
Quadriceps TendinitisBottom of the thigh where it meets the knee
Greater Trochanteric Pain SyndromeOutside of the thigh

Why do my thighs hurt after cycling?

The causes of pain after you have finished your ride are very different from the causes of pain as you are riding.

Muscle aches and pains are quite normal after a cycle, especially if you are still quite new to cycling as a whole.

As you ride on your bike and work your muscles, you are technically forming lots of little microtears in the muscle itself. This sounds bad but it’s actually the way that your body creates and builds new muscle (if you want to take a more detailed look into how cycling builds muscle, then take a look at my article here).

The soreness and pain you feel in your thighs the day after a cycle is simply your muscles responding to the stress and microtears you have caused. This pain is called “delayed onset muscle soreness” (or more commonly DOMS).

The exact mechanism of DOMS is still under debate, but it is likely to do with the way that your body repairs these micro-tears in the muscle, as well as small damage done to the nerves. As part of your body’s response to the damage, it sends more blood cells and other chemicals to the affected area.

These help to repair the damage but cause localized swelling and inflammation as they do so, causing the delayed pain that you experience with DOMS.

How do I get rid of thigh pain after cycling?

So we’ve established what the causes of pain in your thighs after cycling are, but what can you do about them? The majority of the methods I look at below work by increasing blood flow to the thighs themselves, aiding that repair process by supplying the muscles with more protein and other repair molecules.

General Advice

In general, with most types of injury or muscular pain, there are 5 general steps you can take to help speed up your recovery, these can be remembered using the acronym “PRICE”

ProtectWhile your body is recovering, you should ensure you don’t do any further damage.
RestStudies have shown that rest time affects how well and how quickly your muscles heal
IceWe’ll look into this later, but keeping the area cool can help to limit swelling
CompressionCompression helps to limit swelling in the area which can worse pain
ElevationRaising the leg above your heart reduces pain and swelling

DOMS generally gets better on its own after a few days to a week. However, during that time you may find that you suffer from pain and a reduced range of motion from your joints and muscles. The following steps can help to reduce pain and inflammation more quickly.

Active Recovery

Active recovery, be that a very slow bike ride, a walk, or simple stretching can help by increasing blood flow to your thighs, helping to wash away the cells that cause inflammation, and supplying the muscle with more repair molecules.

Active recovery can be quite tricky to get right though, so if you are a beginner then it may be better to take time away from cycling completely while you give your muscles time to recover.

Massage rollers

Another good way to increase blood flow to an area is through massaging the thighs themselves. Many people use a massage roller for this purpose.

Not only does massage therapy make theoretical sense, it has also been shown in studies to alleviate the pain caused by DOMS and improve muscle performance. Just make sure not to go too deep with your massage, this can cause further damage.

Compression garments

The use of compression bandages following exercise has been shown to reduce DOMS and speed up muscle recovery. Compression bandages help DOMS in two main ways.

First of all, they act as a low-level massage, increasing blood flow in the areas by applying constant low-level pressure.

They also help to increase blood flow to the area, in fact, many people with circulation issues in their legs are advised to use compression bandages long-term by their doctor.

Muscle cooling

There is mixed evidence of the benefit of muscle cooling to relieve DOMS or post-exercise muscle pain. Some studies have shown that muscle cooling (for example an ice bath) may have some benefits, however, studies since then have not been able to support this.

In general, if there is a benefit, then localized muscle cooling is not as effective as whole-body temperature reduction.

Supplements

Some people look to take supplements and vitamins as a way to reduce muscle pain after cycling, some compounds have shown possible benefits (for example vitamin C, vitamin E, and Curcumin – A chemical related to Tumeric), however, more research needs to be done.

You need to take care when taking vitamins or supplements as too much of certain vitamins can be harmful. If you are planning to use supplements to aid your riding recovery you should speak to a medical professional first.

Pain killers

I would advise that you should not be using pain killers regularly to recover from your bike rides, if you are in enough pain to require a painkiller, then you are likely pushing yourself too hard or may have injured yourself.

However, some people do take painkillers if they are taking part in a race or important ride where they are pushing themselves harder than normal. It is important to note that if you end up using painkillers to “push through the pain” you are more likely to get an injury or cause yourself more pain in the future.

If you plan to take a painkiller, a nonsteroidal anti-inflammatory drug (NSAID) is likely to be the best choice. Both Ibuprofen and Naproxen are examples of these and both work by reducing levels of inflammation in the body.

As with supplements, you should seek advice from your medical professional before using any painkillers in your recovery from a cycle as certain people can have issues with taking these types of medications. I’d advise listening to your body and delaying your next ride rather than using medication.

How to prevent thigh pain after cycling?

So, we’ve gone over how to deal with pain once it’s there. But is there a better way to prevent thigh pain after cycling in the first place?

Rest and nutrition

The first step to limiting the pain in your thighs following a cycle is to ensure you are getting adequate rest and nutrition both before, during, and after the ride. Rest and nutrition are two of the main factors that will allow the muscles to repair themselves properly.

Good nutrition helps to provide your body with amino acids and protein that form the building blocks that your body uses to repair your muscle. Optimizing your nutrition while cycling also plays a key role, make sure you are replacing your electrolytes if you are out on a long ride as low levels of certain electrolytes such as potassium can make muscle pains worse.

Rest is also key as it gives your body time to properly repair itself, and store up enough energy to do this well.

Stretching

Stretching out the muscles in your thighs is another good way to limit pain or injuries while cycling. If you are suffering from hip or thigh pain then you want to ensure you are stretching out your hamstrings and quadriceps.

A simple way you can do this is by lying forward on your stomach, lifting your foot up to your head, and gently applying pressure onto your ankle to bring it closer to your head.

For more detailed thigh stretches take a look at this link.

Improving your endurance

Riding regularly and improving your muscular endurance will help to develop more slow-twitch muscle fibers. These are the part of the muscle that perform the aerobic exercise we were talking about earlier. As such, improving the amount of these types of fibers can increase how long you can cycle before you start to feel pain.

Check your bike fit

If you are suffering from pain in your thighs, it is worth ensuring you get a good bike fitting. Having your saddle at the wrong height can easily cause an imbalance in the muscles you are using which can lead to pain in areas such as your thighs.

Other areas of a bike fitting can also impact thigh pain, for example, handlebar distance or seat angle can imbalance the way you cycle and cause pain.

Review your cycling technique

If you are feeling most of the pain in your thighs, your cycling technique may be a culprit. Many new riders will cycle in too high a gear for the ride they are doing, which will put more strain on your quadriceps and hamstrings, increasing pain in your thigh.

You should be aiming to have the pedals spin at about 80-90 times per minute (also called your cadence). Increasing your cadence makes the cycle harder on your body overall (testing your fitness) and less on your individual muscles.

Increasing your cadence may take some time to adjust to, but cycling at this faster pace in a lower gear is more efficient and can help out your muscles and joints.

Also, make sure you are not pushing yourself too hard. Pain is your body’s way of telling you to take it easy. New riders or those training for a big event might find they just need to adjust their training regime or take a rest week.

Check your foot placement

Finally, check your foot placement as you are cycling. The ball of your foot should sit over the pedal itself. Placing the back of your foot over the pedal can cause your thighs to take on more of the work and cause them pain.

Another key step linked to this is to look into clipless pedals. These allow you to apply force to the pedal with both the up and down motion of the pedal and help to spread the work over more muscles.

How long before your legs get used to cycling?

Typcially, as you start out cycling, you will be working lots of new muscle groups that aren’t used to working that way. The first few cycles are going to be more painful than normal and this is expected.

Just ensure you are not pushing yourself too hard at the beginning and over time the pain will improve as your legs become used to it.

There’s a saying in cycling that it never gets easier, you just get faster

In reality, there is no set answer to how long your legs will take to get used to cycling, it will depend on many factors such as your base level of fitness, how often you are cycling and what type of cycling you are doing.

As a general rule, I would suggest that you should start to feel more used to your rides after 3 to 4 weeks of regular cycling.

However, to get a better idea of the average time it might take, I spoke to a large group of cyclists to ask them how long they felt it took before their legs got used to the pain of regular riding. The majority fell into the “less than one-month” category, however many took longer than this, with some noting they still had the same level of pain as when they started.

However long it takes your body to get used to cycling, by taking the time to perform the steps we’ve gone through above, you will hopefully be in less pain and hopefully get to a comfortable point more quickly.

Overall

As you can see, thigh pain both during and after cycling is a common problem. However, by taking a few key steps such as warming up properly, you can help to limit this pain as much as possible. And if you do suffer from thigh pain, I hope you now know why you’re getting it and how to deal with it.

Mark Holmes

30-year-old doctor with an interest in cycling, bikepacking, and statistics.

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