Fact Check: Why Do Your Legs Feel Heavy When Running?

Soniya
Lifting weights is a vital part of training for runners. (Image via Pexels / rfstudio)
Lifting weights is a vital part of training for runners. (Image via Pexels / rfstudio)

No one likes doing anything with tired, heavy legs. But so many runners just keep on running even as they fight through the heaviness they can’t explain or shake. It may be a simple fix—or it might not be—but only by considering the causes (and possible solutions) for heavy legs can you make progress toward overcoming yours.

Legs feeling heavy during running has been reported as one of the most common side effects that plague runners and people who exercise in general. So if you’ve been facing persistent leg heaviness while running, here are seven possible reasons why this could be happening to you.


Reasons why your legs feel heavy while running

1) Bad running form

Proper running form is essential for runners. (Image via Pexels / rfstudio)
Proper running form is essential for runners. (Image via Pexels / rfstudio)

Good form improves your efficiency, helping you to run faster. Poor running form causes your body to use energy inefficiently, which not only slows you down but also tires you out faster, making your legs feel heavy.

Therefore, maintaining good running form can prevent you from fatiguing too quickly and reduce the chances of tired legs when running, as your body is working more efficiently.


2) Excessive weight training

Too much of training can cause leg pain for runners. (Image via Pexels / Estudio Polaroid)
Too much of training can cause leg pain for runners. (Image via Pexels / Estudio Polaroid)

For many runners, lifting weights is a vital part of their training. When running uphill, you'll need that core and leg strength to keep your body functioning properly. In truth, a strong core is more than meets the eye.

Many individuals believe that the core consists solely of abdominal muscles. The genuine core, on the other hand, is made up of all the muscles that support and hold your spine upright: the hips, pelvic floor, diaphragm, and, eventually, the rectus abdominus and obliques. It's critical to keep these muscles strong for proper running technique and overall health. However, take care not to overdo it!


3) Overtraining

Overtraining might result in heavy legs while jogging. (Image via Pexels /Victor Frietas)
Overtraining might result in heavy legs while jogging. (Image via Pexels /Victor Frietas)

You're not alone if you enjoy pushing yourself to new heights and putting in long hours. It's motivating to see yourself achieve new goals and see your body change. Overtraining, on the other hand, might result in heavy legs while jogging.

If you're a new runner or just getting started, overtraining is more likely to create weary legs while jogging. If you're feeling leg pain when jogging, it could be the result of a slight injury, in which case rest is the best medicine.


4) Not eating enough carbs & iron

Not getting enough carbs & iron. (Image via Pexels / Engin Akyurt)
Not getting enough carbs & iron. (Image via Pexels / Engin Akyurt)

Your body transforms fat into energy while you run. However, the body's energy resources quickly deplete, forcing it to turn to carbs for more endurance. During running, iron is another crucial component of the energy-generating process.

Iron aids in the transport of oxygen into the muscles, where it is converted to energy. If you have anemia as a result of a pre-existing medical illness or if you're a woman on her period and losing more blood than usual, you're most likely deficient in iron.


5) Dehydration

If you’re dehydrated it can be difficult to run well.(Image via Pexels / Pixabay)
If you’re dehydrated it can be difficult to run well.(Image via Pexels / Pixabay)

When you sweat, water is required to transport vital nutrients throughout your body and aid in the energy production process. 50-60% of your body is made up of water, so if you’re dehydrated it can be difficult to run well. In fact, your muscles can cramp up and fail to work properly when dehydrated, making it harder for you to run at your best.


6) Sleep deprived

Sleep deprived could be one of the reasons your leg feel tired after running. (Image via Pexels / Shvets Production)
Sleep deprived could be one of the reasons your leg feel tired after running. (Image via Pexels / Shvets Production)

When you’re getting ready to go for a run, you probably don’t think about the fact that you need sleep. But sleep is a crucial part of training. The CDC says that one in three people don’t get enough sleep. Running on less than 6 hours per night is bad for your body and mind.

Sleep helps your body recover from a tough workout, so without it, your legs will feel heavy when you run. It can also make it hard to focus mentally, which makes it hard to perform at your best.


7) Poor blood circulation

Poor blood circulation also aids in heaviness while running. (Image via Pexels / Andrea Piacquadio)
Poor blood circulation also aids in heaviness while running. (Image via Pexels / Andrea Piacquadio)

Poor blood circulation is the underlying cause of heavy legs, and it often stems from a lack of energy production. When you get heavy legs running, your body is missing fuel to produce energy. As you run, oxygen circulates into your muscles, where it converts into energy. If there is not enough blood circulating into those muscles, there will not be enough oxygen to convert into energy.


Bottom Line

Running can be a wonderful experience. It benefits your overall lifestyle, and it makes exercise enjoyable—plus it's not too strenuous to fit into your busy schedule. And while running does have its drawbacks, there's no need to avoid it altogether.

If you frequently experience heavy or tired legs while running, it’s best to take steps to address these issues before further injuring yourself or risking a more serious medical issue.