My Leg Feels Heavy When Running

You count on the endurance and strength in your legs to get you through simple and difficult runs of any distance. But what do you do when your legs feel heavy when running? That's a good question and one that many runners ask, especially when their legs feel like lead during the last few miles of a run.

While not uncommon, heavy leg syndrome, or feeling like your legs weigh more than your entire body, can definitely slow you down. However, knowing why this happens and what you can do to prevent it can help you stay up and running at a pace that works for you.

Like most issues related to your body, there is not a "one size fits all" answer to why your legs feel like lead. Why you're experiencing fatigue and heaviness during your training is specific to you — it's even specific to that day. But what are heavy legs and why do your legs feel heavy during exercise?

"The term "heavy legs" refers to feeling fatigue, and typically there are no other signs or symptoms," explains Dr. Jose Antonio Lozano, MD, OPA, SFA, Assistant Professor in the Doctor of Physical Therapy Program at the University of St. Augustine for Health Sciences.

Lozano says this heavy feeling can occur at any time, especially if you're not adapted to the level of exercise you want or expect to perform. The cause of this, he explains, has to do with a variety of factors including coming off a longer period of rest (for whatever cause), being overweight, or a change in the level of physical participation. Regardless of the cause, Lozano says most people dealing with heavy legs during exercise will experience tiredness and a variety of other symptoms, including pain.

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Most of the time, experiencing heavy legs during exercise is a symptom of overuse. That being said, Lozano points out that complaints about tired, heavy or fatigued legs as symptoms can also be a result of a venous problem, which may indicate the onset of other conditions like chronic venous insufficiency and phlebitis. However, with these conditions, Lozano says swelling, and the presence of varicose veins makes this diagnosis easier to define as a cause.

Another medical condition that may resemble heavy leg syndrome is chronic exertional compartment syndrome (CECS). CECS produces lower leg pain as a result of exercise and sometimes makes your legs feel heavy when running. If the heaviness you're feeling relates to CECS, you will also experience a crampy feeling that starts during exercise. Typically, the pain returns in the same location each time you run, despite resting and feeling better when not running.

Maintaining a training schedule and staying fit is a priority for many people. If your legs feel heavy when running, you may begin to notice a slump in your workouts. To help keep you on track both during your runs and after exercise, it's important to address specific lifestyle factors.

The lifestyle factors that make your legs feel like led might be different from your running partner's triggers. That's why it's critical to look at everything you're doing, or not doing, that may be contributing to this annoying problem.

First and foremost, you need to identify and find the correct level of running for your fitness level. If the training plan you're following is too aggressive, scale back, and consider asking a trainer or physical therapist for guidance. Once you've determined the appropriate training plan for your needs, it's time to consider other factors that might make your legs feel heavy when running and make your legs feel heavy after a workout.

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If you've been running for a while, there's a good chance you know that hydration and nutrition make a significant difference in your stamina, speed, distance and other performance tasks. But what you may not know is skipping out on proper hydration or nutrition can also be a reason your legs feel heavy when running.

That's why a focus on hydration before, during and after your run is so critical. Many runners mistakenly think they only need to kick up the hydration in the hours before their run and during a workout. But to prevent fatigue in your legs, staying hydrated all the time is important.

Finally, it's not just the amount of food you eat that helps you train and perform at your best, it's also the quality of nutrition that you're putting in your body, especially if you're running long distances. Complex carbohydrates, lean protein and healthy fats are all essential nutrients your body needs in order to fuel your runs, or any other form of exercise.

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Preventative care can go a long way in keeping your body healthy and your legs ready to run. Everything from training plans and rest days to stretching and resistance training plays a role in your performance.

If you're hitting the pavement a lot and not spending any time in the weight room or stretching, that might be another reason your legs feel like lead when you run. Including resistance training exercises at least two days a week not only helps you run better, but it also helps keep your body balanced and reduces the chances of injury.

Scheduling rest days from running can help prevent overtraining, which contributes to heavy legs during exercise. "Rest is the best option when identifying an overuse syndrome or preventing heavy leg syndrome," says Lozano. The amount of rest will depend on your fitness level and current level of training.

One area that often gets overlooked is how you dress for the activity. Comfortable clothing and good quality shoes and socks do make a difference in how you feel and perform. That's why Lozano says to dress comfortably, with loose clothing. Have a pre- and post-activity routine. Lozano recommends massaging the lower extremities along with stretching in the pre-activity session. Additionally, when you're done running, he suggests applying ice/heat, depending on the stage.

Finally, when it comes to your training plan, it's important that you stick to a schedule that allows enough rest between workouts and still moves you forward with your training. Along those same lines, consider modifying the number of days, the course, or the patterns of running if you notice that your legs feel heavy.