Top 6 Reasons You Feel Sleepy & Tired After Running

runner dealing with injury

If you’re wondering why your runs are making you sleepy and tired, then read on to learn more about what could be wrong and how you can fix the issue.

Feeling sleepy after a run is not only tiresome but also likely a sign that you’re not taking good care of your body as well as you should. When it’s the case, you’ll want to find out what’s causing this, especially if you’re serious about making the most out of your day.

That’s where this post comes in handy.

In this article, I’ll discuss the main reasons behind the sleepiness you experience after running as well as what to do about it.

Sounds great?

Let’s lace up and dig in.

Reason – 1 Eat Well

One of the most common reasons you feel sleepy boils down to bad nutrition choices.

Food provides the raw materials your body needs to break down sugars and fats into energy during your runs.  Devoid of it, your energy levels will dwindle, especially post-run.

What, how much, and when to eat depends on you, but as a rough guideline, avoid running on empty, especially if you’re planning on a long run or interval workout.

At the very least, have a carb-rich snack 60 minutes before you run.

Some of the best pre-run options to help provide you energy without upsetting your stomach include:

  • Low-fiber granola bar
  • A piece of fruit, such as an apple or a banana
  • Half of a sports energy bar
  • Bagel or Toast with Peanut Butter
  • Whole Wheat Waffles or Pancakes
  • Fig Cookies
  • Half-cup of dry cereal
  • Graham Cracker Squares With of Honey
  • A slice of toast with jam
  • Oatmeal

Planning to run for more than 90 minutes? Have gels, sports drinks, and other fuel to keep your energy levels up.

As a guideline, take in about 100 calories after 60 minutes of running, then and then 100 every 30 to 45 minutes.

Then, following your workout, replenish your stores as quickly as possible.

Your muscles are most receptive to nutrients the first 30 minutes after exercise. By eating soon, you may reduce your risks of muscle soreness as well as fatigue.

Here are some great post-run meal ideas:

  • Egg omelet with avocado spread on toast.
  • Salmon with sweet potato.
  • peanut or almond butter on whole-wheat bread
  • Oatmeal with fruit
  • Cottage cheese and fruit
  • Oats with milk and dried fruit
  • Veggie omelet with a slice of whole-grain bread
  • Pretzels with nuts and fruit
  • Yogurt with granola
  • A hard-boiled egg with fruit
  • Brown rice with chicken or salmon and veggies
  • Tuna salad sandwich on whole-grain bread.
  • Tuna and crackers.

Reason – 2 Drink Your Water

One of the pressing symptoms of dehydration is fatigue. In fact, even mild dehydration can cause some fatigue or sleepiness after exercise.

That’s why if you’re not drinking enough water before, during, and after your runs, you’re more likely to feel exhausted afterward.

It makes sense. Water is a key component that makes roughly 60 percent of the human body. So, for your body to perform at its best, water is non-negotiable.

Losing water means losing lots of electrolytes, which are key to proper muscle function, especially during exercise.

Don’t take my word for it.

During an experiment reported by the Journal of Nutrition, researchers assessed the mental skills of 25 subjects who either had enough water to stay sufficiently hydrated or were put into a lightly dehydrated state.

The mildly dehydrated group reported symptoms such as headache, loss of focus, low mood, and a sense of fatigue both at rest and during exercise.

Again, how much water you need depends on your sweat rate, climate, temperature, weather conditions,

But as a runner, drink at least 64 ounces of water every day. Have more if you run long in the heat and/or tend to sweat a lot.

As a rule, start your runs properly hydrated by drinking a large glass of water 30 to 45 minutes before heading out.

Although I got nothing against running on empty, it’s never a good idea to long the miles without drinking water. Dehydration makes fatigue worse, which may make you sleepy after running.

For long runs, have access to fluids throughout your course. Check this article for more.

You can also alternate water with a sports drink to help replace electrolytes or opt for an electrolytes supplement to keep a proper balance.

Are you well hydrated?

Research shows that if you’re feeling thirsty, you already lack fluids. Studies have also reported that dehydration may also manifest as hunger.

What’s more?

If you are feeling tired after a run, monitor your hydration status—the best way to check the color of your urine.

You’re well-hydrated when your urine is pale yellow or almost clear in color.

runners with a headache

Reason – 3 Sleep Enough

The importance of proper sleep for optimal performance cannot be stated enough.  It’s key for rest, repair, and replenishment of resources required for your day-to-day functions.

In fact, the most likely reason behind your sleepiness after exercise had to do with your sleep routine—as in the length and quality of your slumber.

Sleep deprivation negatively affects your body’s internal metabolic process and logging in fewer sleep hours than you should wreak havoc with your hormones and increase your appetite.

Keep depriving yourself of sleep, and you’ll be setting yourself up for weight issues and other health problems.

So how much is enough sleep?

Shoot for at least seven to eight high-quality hours of sleep a night. That’s the recommended amount for most adults, but feel free to sleep a little bit more on your hard training days.

Again, listen to your body and follow your own judgment.  Your body is your coach—as long as you’re willing to listen and follow its commands, you’ll on the right way.

Reason – 4 Avoid Overtraining

You’re more likely feeling tired and sleepy following a workout simply because you’re guilty of the “too’s”—running too much, too fast, and/or too hard.

Sure, feel free to push your body, but not to the limit while logging the miles.

Get this – if you train hard day-in-day-out, you’ll likely push your body to the breaking point, resulting in overtraining.

Training hard builds up lactic acid and other waste products in your muscles and tissues, which in turn leads to fatigue and weakness.

Your body needs time and plenty of it to get rid of the waste products and patch up damaged muscle fibers.

So how do you nick overtraining in the bud?

First, have at least one or two days of complete rest each week, along with some cross-training days.

Follow hard sessions, such as intervals, tempo runs, hill runs, and long runs, with a recovery day or day off.

You can also schedule recovery into your training phase by periodically giving yourself “easy weeks,” in which you drop cut your mileage by 50 percent every four to five weeks.

During your recovery days, you can choose to do nothing but rest the whole day or cross-train.

Some of the ideal cross-training options for runners include cycling, swimming, yoga, strength training—you choose.

You should also keep track of overtraining. Some of the early signs include:

  • Insomnia or difficulty falling asleep
  • Mediocre athletic performance
  • Persistent aches and pains
  • Loss of appetite
  • Elevated heart rate
  • Lack of exercise motivation
  • Sickness or compromised immune system
  • Persistent soreness.

If you find yourself dealing with more than a few of these, give your body the recovery that it desperately needs.

Next, examine your training schedule, then determine your running paces, mileage increases, and recovery days.

It’s key to choose the right training pace for each session. Running too fast when you’re supposed to go slow can cause undue fatigue.

Your running schedule should include a range of training paces and intensities throughout the week, depending on your training goals and personal preferences.

Reason – 5 Check Your Medication

Your post-workout sleepiness can also be caused by any form of heavy medication.

Some of these include:

  • Antidepressants, such as Zoloft and Prozac, can cause excessive fatigue, making it hard to summon up the motivation to run.
  • AntihistaminesBrompheniramine, diphenhydramine, and hydroxyzine, among others, are all are used to treat allergies.
  • Anxiety medication – such as Klonopin, Xanax, Ativan, and Valium have the side effect of making you feel weak or drowsy for a few hours to several days.
  • Blood pressure. Beta-blockers, like Tenormin, Toprol XL, and Lopressor work by slowing your heart, which can make you feel tired, both during the workout and afterward.

If you’re on one (or more) of these medications, don’t stop –nor change your dose—without consulting your doctor first. Going cold turkey can have serious consequences.

If all possible, try taking your medication three to four hours before you head out for a run—or simply consult your doctor for alternatives that are less likely to cause fatigue or sleepiness.

Reason – 6 You have got a Medical Condition

If you’re eating well, staying well hydrated, and are sleeping enough but still find yourself sleepy after running, then it’s time to rule out any underlying medical issues.

In other words, consult your doctor for a thorough exam. There’s a number of health conditions like heart and thyroid diseases that can make you feel tired or sleepy after exercise.

What’s more?

Blood sugar issues, such as prediabetes and diabetes, can also contribute to fatigue and sleepiness, especially if your blood sugar drops after training.

Additionally, different infectious diseases, such as Lyme disease, herpes virus, or Epstein-Barr virus, can induce fatigue as your body fights the infection.

In general, consult your doctor for fatigue if it has lasted for many weeks, and it’s accompanied by these other symptoms:

  • Blurry vision
  • A mix of constipation, feeling cold all the time, weight gain, and dry skin
  • Depression, anxiety, or feelings of severe stress
  • Insomnia, or frequent episodes of interrupted sleep
  • Frequent and severe headaches
  • Recent and unwanted weight gain
  • Unexplained weight loss or gain
  • Inability to urinate
  • Suicidal thoughts
  • Abnormal bleeding, including vomiting blood or bleeding from your rectum

When To Nap After A Run?

So should you take a nap after a workout?

The answer really depends on you and your body. If a quick nap will help get you back on track, then why not it.

But if you’d rather keep moving, then go for it.

Decided to nap? Then make the most out of it by doing the following:

  • Post-Run ritual. Drink plenty of water and stretch your muscles first, then shower—all before you take a nap. Without a proper post-run ritual, your muscle may start to cramp while you’re taking a nap.
  • Nap At The Right Time. Avoid napping later in the day. Time it at around 1:00 p.m. and 3:00 p.m.—which works great if you usually run in the morning or around noon.
  • Cap The nap. Limit your naps to 20-30 minutes. Doze off for longer, and you might fall into a deep sleep, then wake up with sleep inertia. In fact, the longer the nap, the more you risk feeling groggy afterward.
  • Set The Alarm. Now you have the perfect nap time; it’s time to make the most out of it. Start by setting the alarm to help nail those 20 minutes.
  • The Right Environment. For the perfect 20-minute nap, you want a quiet, dark place with a comfortable room temperature to lay down. If possible, feel free to use earplugs, eye masks, or white noise to help tune out distractions.


There you have it. If you often sleep exhausted or sleepy after your runs, today’s article might all you need to figure out what’s wrong as well as what to do about it. The rest is just details.

Please feel free to leave your comments and questions in the section below.

In the meantime, thank you for dropping by.

Keep Training Strong.

David D.