6 Simple Ways To Prevent Heavy Legs When Running

Running isn’t a simple thing to pick up, it takes some effort. However, running is enjoyed by millions all over the country.

Tired, heavy and even achy legs are something a lot of runners suffer from, and can put off a lot of people from wanting to go on a run.

However, you shouldn’t let this put you off from running. 

There are a few reasons why you may suffer from heavy legs, this can be from dehydration or overtraining.

In this article, we’ll be going through some of the main causes of heavy legs and suggesting some simple ways to prevent heavy legs when running. 

Running Form

Your running form is a really important thing to get right. Poor running form can put extra stress onto your body, which then can cause heavy and tired legs. 

There are quite a few things to consider when it comes to your running form. How long your foot stays on the ground has a huge impact on your running form. Alongside, how high you bounce with each step you take, as thus can create even more stress when you are landing. 

Also you need to make sure that you are wearing the correct kind of shoes for running. It may sound silly, but wearing the wrong shoes also affects your form and can be a cause of heavy legs. You want lightweight shoes that support your feet and ankles.

Your shoes need to be supportive, otherwise this can cause more stress for your foot when it touches the ground.

Ideally, you want to take quick steps and try not to bounce at all. If you do this, the pace will improve and the stress that you are putting on your legs will also decrease.

Avoid Overtraining

If you fall in love with running, then overtraining can happen without you realising. If you are training for a marathon or a half marathon, it could be really tempting to train everyday.

Obviously, you have to get yourself physically and mentally prepared, but you don’t want to overwork your body. 

Yet, overtraining doesn’t mean just running lots of miles in a week. If you are training, then you will have a training plan to follow. If this training plan moves on too quickly for you and you aren’t ready for the jump, this can cause issues.

Also attempting to do too much after coming back to running after a break or an injury is an issue.

If you do overtrain, this can lead to injuries that you don’t want if you are training for a marathon. Also it can cause illnesses, as you are working your body too hard that it can’t handle anymore. Heavy legs can be a sign that your body needs a break.

Rest days are important and are beneficial for you and your body. Therefore, if you are overtraining, you must take a couple of days off and reduce your training plan until you start to feel better once again. 

Drink Water

When you do any kind of exercise, drinking plenty of fluids is crucial. Whether you are completing a long run or going for a short jog. The hydration levels change depending on the exercise and the intensity of the exercise that is being completed.

However, you are trying to replace the fluids that you lost throughout the workout by sweating. 

If you are dehydrated, then you haven’t drunk enough fluid. You may notice that you have a dry mouth, muscle cramps and you can suffer from fatigue. When you are dehydrated, your legs will feel a lot heavier, and running feels like a lot more work and effort. 

The easy way to solve this problem is by making sure you are drinking plenty of water throughout the day. If you know you have a run coming up, then make sure you have drunk enough, so that you won’t become thirsty during the run.

However, you can take fluid with you on your run, so when you are starting to feel thirsty have a drink. Ideally, when you start to feel thirsty you need to drink some fluids. 

If you are exercising more than you use to, then you need to adjust your hydration levels to match your exercising levels.

Alongside this, if the weather is getting hotter and you are still going out on runs, you need to adjust your hydration levels because the heat will make you thirsty quicker and more often. 

Diet – Iron Levels And Carbohydrates

If you are constantly dealing with fatigue or tired and heavy legs when running, then it might be worth checking your iron levels.

Most runners will get the right amount of iron that they need from their diet and what they are eating. However, sometimes you don’t naturally get the right amount of iron that your body needs and craves for. 

If you have an iron deficiency, then your body is struggling to get the right amount of oxygen to your muscles while you are running.

This is then what causes you to have heavy legs. It can be a bit more difficult for vegans and vegetarians to get the right amount of iron in their diet.

If you are a vegetarian or vegan, you need to make sure that you are eating a wide variety of iron- rich foods like wholemeal bread, pulses and leafy vegetables. 

Alongside this, for female runners your period puts you more at risk of an iron deficiency, especially if you suffer from heavy bleeding. Therefore, you need to make sure that you are also eating enough iron-rich foods to combat fatigue and heavy legs.

However, if you are on a low carbohydrate diet, this can also create heavy legs while running. If you have cut down on the amount of carbohydrates you are eating, then the body can’t store as much glycogen in your muscles that it needs to.

Then when you are running, you don’t have as much energy because not enough glycogen has been stored, which then results in heavy legs.

Making sure that you have a healthy and balanced diet is the best way to help combat heavy legs. However, you can also take iron supplements, which is normally seen in the form of a tablet that you can take daily.

However, the tablet shouldnt be the only thing you take to combat this. You should still try to have as much iron in your diet as possible. Also, trying a ketogenic style of eating may help you if you want to stick to a lower carb diet.

Cooling Down

After a long run, the last thing you might want to do is cooling down and a lot of runners don’t think it’s necessary to cool down.

However, static stretching, which is also known as cool down stretching will really help you out a lot after a run. If you suffer from stiff or tight muscles or sore muscles, then doing static stretches after a run will help prevent this from happening. 

Static stretches are the key here, not dynamic stretches. With a static stretch, you hold the stretch for 20 to 45 seconds. You want to try and do a stretch for each muscle group.

In running you use your arms, back, hamstrings, quadriceps and glutes, so these are the areas you need to focus on.

After each run, try to give yourself 5 to 10 minutes to complete these stretches. This will also help you lower your heart rate and helps to prevent any heaviness or soreness. 


You need to have energy to be able to go on a run, and by getting the right amount of sleep will help improve your performance while running. You don’t want to be tired, as this can make the run more challenging.

If you don’t get enough sleep then you can experience tiredness along with heavy legs. A study in 2014, discovered that there is an effective relationship between the amount of sleep you get and exercising.

Getting enough sleep, allows your body to restore its systems. These systems are your skeletal, muscular, nervous and immune systems. Getting enough sleep allows your body to repair itself, so it can work well the next day.

Making sure you have a good night’s sleep should be a priority, because trying to complete a decent run on a few hours of sleep just won’t work. Your body needs time to restore itself.

That is why most of the top athletes try to get around 7 to 9 hours of sleep every night. If for whatever reason you can’t physically have 7 hours of sleep a night, then short afternoon naps may be useful. 


Heavy legs can make running feel like a very difficult task to do. Every runner has experienced heavy legs at some point in their training. Yet, there are ways to combat this issue.

You need to listen to your body and when you begin to feel those dreaded heavy legs, that means something isn’t right. Although, if you have a healthy lifestyle, by eating a balanced diet and getting enough sleep and stretching after running you should find those heavy legs a thing of the past. 

Matt Williams