We all know that running is a great way to get moving and stay in shape. But for many people, it can be hard to find the energy needed to keep running long distances – or even short distances – if fatigue tends to creep in during your run. Learn how to not get tired when running in this post, with key tips on how to increase your endurance, what you should do before a workout, and recovery strategies. If you follow these steps, you shouldn’t feel exhausted at the end of your run!
Disclaimer: This post was written and reviewed by Chrissy Carroll, RD, USAT Level I Triathlon Coach, and RRCA Running Coach. It is for informational purposes only and should not be construed as individual training advice or medical advice. Always consult your doctor with any medical concerns.
Why do you get tired when running?
It’s not always easy to pinpoint the exact reasons why you get tired when running. That said, there are a few common factors that usually contribute to fatigue in runners:
- Running too fast in a workout.
- Running on a hilly course for the first time.
- Including too many speedwork sessions and/or not enough rest days, so your body can’t recover properly from one workout session to another.
- Not getting enough sleep during the week.
- Eating too little before a workout.
- Not eating proper recovery foods.
- Not eating a proper daily diet.
- Having an underlying medical condition. This could be a condition that you are not aware of yet. Or, it could be a condition you are aware of, for which regular physical activity is prescribed but may be difficult due to exhaustion levels.
- Experiencing mental fatigue (your brain is telling you you’re tired before your body actually is).
Training tips to avoid running fatigue
You may not be able to completely avoid some of the aforementioned factors that contribute to your fatigue. That said, you can reduce your risk of feeling tired on a run by following these training tips:
1. Make your easy runs easy.
Many runners do their easy runs too fast, and their hard runs too easy. About 80% of your runs should be done at an easy, conversational pace.
One of the easiest ways to assess if you’re running the right pace is using an RPE scale – otherwise known as rate of perceived exertion. On a scale of 1 to 10, where 1 is sitting on a couch and 10 is being chased by a bear, your easy runs should generally be around a 4-6. (And recovery runs might be even lighter, around a 3-4).
If you’re doing your easy runs around a 7-8, that could be a clear reason for feeling tired on the run.
RPE is generally my favorite way to assess how tough a workout is. But if you really love nerding out on running data, you could also do a lactate threshold field test and use that to set heart rate zones for yourself. That way, you know exactly where your heart rate should fall on an easy run.
2. Ramp up mileage gradually.
A common reason that new runners feel tired? Too much, too soon.
Take a look at how many miles you’ve been running each week for the last two months. Have you spent time building a solid base? If not, it’s time to take a step back.
You want to avoid increasing your mileage by more than ten percent a week. If you’re running fewer than 20 miles per week, you may be able to be slightly more aggressive than ten percent, but a gradual training plan will lead to less risk of fatigue (and injury) compared to a quick plan.
3. Keep the right balance of easy runs and hard runs.
In addition to not ramping up overall mileage too quickly, you also want to make sure that you’re using a training plan that’s appropriate for your current fitness level.
While an advanced runner training for a marathon will likely have long interval speed work days, a new runner training to cross the finish line of their first 10K doesn’t need this.
Adding in speedwork too soon or too many days will increase fatigue and also increase injury risk.
With any running plan, the foundation should be building a base of easy, conversational runs. For new runners, that will often start with a run/walk plan. As you build up to being able to consistently run a few miles and get a solid base of that over several months, you can then add in some hills and tempo runs. Once you’ve got at least 6 months of consistent running under your belt, you can add in short or long interval workouts if desired. (You can read more about these different types of running workouts here.)
Keep in mind that all runners don’t necessarily need interval runs, especially if they’re simply training for fun and don’t have time goals. If you’ve been forcing yourself to do interval runs and are feeling tired, try swapping those out with a comfortably run (for an easy option) or a hilly run (for a more challenging option). See if this helps your feel more energized with your training.
Of course, if you are a more advanced athlete and you do have time goals, those interval runs will be quite important. They should feel challenging, which is why it’s important to make sure your other easy runs are actually easy (as mentioned above). Don’t try to do speed work in every session.
4. Add variety to your workout routine.
If you think your fatigue might be from feeling burnt out on running, pull back on the number of days you’re running. Try adding cross-training exercises to your workout routine such as cycling, swimming or yoga.
Sometimes, the body just might need a break from one activity. Adding cross-training allows you to continue working on your fitness during that break.
5. Be sure your running posture is correct.
Many people tend to round their back when they run or clench their arms, and this can lead to wasted energy and tiredness. Keep your spine tall and arms swinging comfortably by your sides while running. Check in periodically with yourself, especially during a long run, to make sure you’ve got the right posture.
6. Consider changing the time of day that you run.
There is no one “right” time of the day that you can run. Some people prefer to run in the morning before work, others may like running at night. But if you constantly feel tired during your run, try switching things up.
Perhaps you’re a night owl that has been trying to run in the early morning, but it’s just not jiving with your body’s natural rhythm. Try doing your runs in the early evening and see how you feel.
On the flip side, maybe you always want to run after work, but can never quite muster up the energy after a long day at the office. See if setting your alarm and getting up earlier will help you get it done.
7. Get support.
Work out with a partner or in a group so it’s more fun and motivating. A workout buddy can push you to keep going if it gets tough; they’re very useful when the fatigue is more mental than physical.
Similarly, finding a group run (like with a local running store or running club) may help keep you distracted during the run so you don’t have a chance for your brain to think about feeling tired.
8. Get enough sleep.
While sleep may not seem like a “training tip”, it’s essential for runners. Most adults unfortunately fall short on the amount of sleep they need. When it comes to sleep for athletes, aim for at least 7-9 hours per night.
9. Take a short break.
Sometimes you might just need a few days off all together from workouts. Feeling tired may be your body’s way of saying you need a break. A few days off will not hurt you in the grand scheme of your training plan and overall fitness goals. Feel free to do light activity during this break, such as taking breaks at work to move and stretch, going on walks with your significant other, or doing some gardening in your yard.
Nutrition tips to avoid running fatigue
On the nutrition side, there are also several strategies that can help ensure you’ve got peak energy levels for your run.
10. Eat a good pre-workout meal or snack.
This is especially important if you’re heading out on a long run. While you can get away with running a few miles fasted, running longer distances can be quite difficult without fueling your body beforehand.
A proper pre-run meal or snack should include a good source of easily digestible carbohydrates, along with some protein. Those carbohydrates top off your energy stores, helping you run strong.
Avoid too much fiber, which can have you rushing for the porta-potty mid-run.
And, remember that the key to a good pre-workout meal is timing. Eating too close to your run can lead to stomach distress or even nausea, which is often worse than just feeling a bit tired. If you’ve got a long run coming up, try to eat at least an hour beforehand when possible.
11. Stay hydrated.
Stay hydrated, both before the run and as you’re running! Dehydration can lead to feeling tired on a run, and also affects performance.
These days, many runners are nervous about overhydrating. This can lead to a condition called hyponatremia, which refers to diluted blood sodium levels. Hyponatremia is a very real concern, and we shouldn’t overdo hydration during a run. It is much more serious to suffer from hyponatremia than slight dehydration.
That said, dehydration is typically more common among runners. Since significant dehydration can impact performance, it’s wise to keep a careful balance of fluids.
If you’re drinking to thirst, and not forcing down fluids or skipping fluids despite feeling thirsty, you’re likely doing a good job with hydration balance.
Another trick you can try to see if you’re hydrating right is to conduct a sweat test. Weigh yourself before and after your workout (sans clothes). If you lose more than 2-3% of your body weight, it might be worth focusing a bit more on hydration during your run. (Conversely, if you’ve gained weight, you might be overdoing the fluids).
For workouts under an hour, plain ‘ol water is just fine. For workouts over an hour, use an electrolyte drink.
12. Fuel right during long runs
If you’re exercising for more than 75-90 minutes, it’s time to start fueling during your run. Eating carbohydrates during your run can help provide quick energy to your muscles, which helps keep your endurance up throughout the entire run.
The type of fuel is an individual choice, and you should practice during training to find the best option. Manufactured sports foods or regular grocery store foods can work. Examples of fuel include:
- Energy gels
- Sport beans
- Energy chews / shot blocks
- Fig newtons
- Sports drinks
13. Eat proper recovery meals
After a tough workout, it’s wise to ensure you’re supporting recovery. Runners don’t need to go crazy with eating a huge meal after every workout, but it’s smart to eat a snack after a long run or intense speed workout if you don’t have a meal planned within an hour.
If you’re doing two-a-day workouts or are an elite athlete, then it will be more important to ensure you have a balanced recovery meal after your first workout of the day.
Eat a meal or snack that contains both carbs and protein. Carbs replenish the energy stores in your muscles which will help ensure you’ve got enough energy for the next run. This is particularly true for speed workouts, which rely more on carbohydrates as a source of fuel compared to longer, steady-state runs.
Protein in your recovery meal supports muscle repair and recovery, which is important for overall health and keeping your muscles strong during training runs and races.
14. Eat a balanced daily diet.
As a dietitian, there is a common issue I see that causes feeling tired on a run: following a very restricted diet. This could be restricted as far as calories, but could also be restricted to a very low-carb, ketogenic-style diet.
While some long course runners may fare OK on a ketogenic diet once they’ve adapted to it, sprinters or shorter distance runners will almost always suffer (since those events require more reliance on stored carbohydrates for fuel).
For the most part, I recommend that runners follow a balanced diet that contains all three macronutrients: carbohydrates, protein, and fat.
As mentioned, carbohydrates are a key source of energy for the body. Examples of healthy carbs for runners include: fruits, oatmeal, potatoes, sweet potatoes, brown rice, yogurt, squash, and more.
Protein is also important on a daily basis, as it helps support muscular health. Some examples of protein-rich foods include: milk, yogurt, cottage cheese, red meat (such as beef), chicken, fish, eggs, beans, and tofu.
The third macronutrient that runners need to be mindful about is fat. Fat is important to eat because it helps with feelings of fullness, provides energy, and assists in the absorption of fat-soluble vitamins. Healthy fats come from foods like avocado, olive oil, nuts/seeds, and fish.
15. Evaluate your risk of RED-S.
RED-S stands for Relative Energy Deficiency Syndrome. This is a condition that can occur when you’re not getting enough calories to support your level of physical activity. RED-S can have numerous physiological and psychological effects like missed periods, anxiety, reduced performance, mood changes, and poor bone health. If this sounds like something you are experiencing, talk to your doctor or dietitian.
16. Check for nutrition deficiencies.
It may also be a good idea to see your doctor for a physical to determine if there is a nutrition deficiency causing your fatigue. Iron deficiency anemia is one of the more common nutrition deficiencies that can lead to feeling tired on a run. A doctor will be able to check your iron levels to see if this is causing issues.
If you have iron deficiency anemia, you’ll likely need to take a supplement to help bring your levels up to normal. For slightly low levels, you may be able to bring them up with simple changes to your diet. You can increase your iron intake by eating more lean meat, iron-fortified cereals, beans, tofu, and leafy green vegetables.
Mental tips for running when tired
Sometimes the fatigue you’re feeling on a run is not related to training or nutrition – instead, it’s simple mental fatigue.
Below are some mental tips that can help you get through the last few miles of your run.
17. Focus on positive thoughts.
When we’re tired, it’s all too easy to fall into negative thought patterns. You might start to think in your head “I can’t make it; I’m going too slow; I shouldn’t have considered running this distance.” (Do those negative thought patterns resonate with anyone else? Because I know I suffer from them sometimes!).
Words carry so much power – but they don’t have to be negative in this moment for us if we consciously decide otherwise. So next time you find yourself feeling fatigued during a run, change those thoughts.
You might tell yourself, “This is such a beautiful day”; “I’m so grateful to be on this run right now and not sitting at work”; or “Wow, I feel awesome!” Fake it ’til you make it, and you’ll notice the difference in how you start to feel.
18. Remind yourself of your “why”.
Think about why you started to run in the first place. Was it to help you get in shape? Perhaps you were hoping running would help your mental health? Or maybe your goal was to raise money for charity, or just explore new places, or have fun with a new healthy hobby.
Whatever the reason may be, when you start to feel tired, remind yourself of why you started this journey. When you focus on your why, you can make it through that last mile with ease – because you believe that there’s something worth finishing for.
19. Distract yourself.
Your brain often gets tired before your body, so find a way to distract it. For example:
- Put on your favorite playlist or podcast to keep you going. I’m a huge fan of listening to stand up comedy on a long run.
- Try a new route – maybe you’re a road runner and you switch things up with a trail. Or maybe you decide to run downtown and take in the sights.
- Find a buddy to run with you. Talking to someone for a few miles can make it go by much more quickly!
- Mix in a fun running workout – you could try some of these fartlek workouts, or a couples running workout with your partner.
20. Break it down.
If you’ve set your heart on running a half marathon, it can seem overwhelming to think about running 13.1 miles straight – especially if you’re feeling tired on your first 2 mile training run.
First, be sure you break down your goal into feasible steps. Giving yourself enough time to train is important for both your body and your brain. Find a training plan that builds up gradually and allows you to build confidence in your abilities. This could be a free training plan you find online, or you could work with a coach to develop one specific to your fitness level.
Second, apply this concept during your individual runs. For example, when you’re nearing the half-way point of your training run and you feel tired, remember that there’s an end in sight. It might not seem possible to maintain a strong pace for another six miles all at once – but it is absolutely possible if you break down those last six miles into manageable chunks (i.e., one mile at a time).
21. Visualize success.
Research has shown that visualization has a powerful effect on your brain and body.
Before a big race, visualize yourself running strong for the duration of your event. As you’re running, think about crushing milestones like hitting the half-way point and crossing the finish line. Imagine how you’ll feel when you finish; what your friends at the finish line will say; how great that post-race brew will taste.
The more you visualize success, the less likely it is that your brain will be plagued by self-doubt.
Don’t forget to rule out medical issues
For most people, simple tweaks to their training or nutrition routine, or mental preparedness, will help them feel more energized during a run. However, some people may be suffering from a medical condition that causes them to feel tired. It’s important to rule these out with a doctor if you start to notice frequent fatigue. For example:
- Diabetes: Research shows that people with Type 2 diabetes may experience fatigue (during everyday life as well as during exercise) due to an imbalance in glucose levels, other physiological aspects of the disease, and co-occurring psychological issues like depression.
- Sleep apnea: People who suffer from sleep apnea will often feel tired when they wake up because they were unable to get enough restful sleep, which can lead to fatigue during their fitness sessions.
- Hypothyroidism: Low thyroid hormone production can lead to feeling sluggish and fatigued throughout the day, including while exercising.
- Chronic fatigue syndrome: This is a chronic condition that causes extreme fatigue and may also impact the immune system. According to the Mayo Clinic, physical activity may worsen symptoms.
- Food sensitivities: Food sensitivities are a bit different than allergies. Generally, these are a non-IgE mediated response to a food, but the reaction may still involve other parts of your immune system. Fatigue may be one of many symptoms of a food sensitivity.
- Anxiety or depression: Psychological challenges like anxiety or depression may lead to problems with energy levels for exercise. Consider talking with a therapist is trained in helping clients understand how to manage these conditions.
The above list is not exhaustive; there are many other possible medical reasons for fatigue. If you experience unexplained or persistent symptoms of any kind please see your doctor as soon as possible.
A Final Word
As you can see, there are many reasons you may feel tired during a run. Remember though: there are several ways you can combat fatigue and continue running for as long as possible. By fueling your body with healthy foods before, during, and after a run; hydrating properly while exercising; getting plenty of sleep every night; and ramping up your training gradually, you’ll put yourself in the best spot to not get tired while running. Don’t forget to put the mental tips into place as well, and I have no doubt you’ll be energized as you pound the pavement.
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