8 Reasons Why You Feel Tired During Workout and How to Overcome 

Shayla Whitter

Updated on:

You leave for the gym enthusiastically with a plan to burn maximum calories. But, after a few minutes of exercising, you witness your energy levels dropping, and after a while, you are completely exhausted, and finally give up. 

While everyone has their days off, constant lower energy levels while working out can be a symptom of something unusual or even more serious.

If you are tired of working out more often, you must get to the root causes of your fatigue. This article highlights the reasons that are making you feel tired at the gym. It also refers to the steps that can help you get your energy back.

There can be multiple reasons behind feeling tired during work out like, general to specific health issues, hormonal imbalance, deficiency of any nutrient, etc. Possibly having these problems will make you feel exhausted during and after a workout.

We often ignore signs of fatigue during the day, National Institute of Aging explains such signs as alarming as they can be due to some medical issues or medications; even emotional burdens can make you feel tired.

If your body doesn’t recover from fatigue, then you need to consult a healthcare practitioner to keep yourself safe from serious health problems. 

Here are 8 reasons why you feel tired during workout and what to do to get it back.

You’re Not Having Enough Sleep

Sleeping patterns are the key to your health and fitness. If you feel constantly tired during a workout, even throughout the day. Then possibly, you are not getting enough sleep. Your body requires proper time to rest and recover.

To keep your health at an optimum state, you must balance your sleep-wake cycle. Otherwise, you will stress out your body, and routine activities will become a burden for you.

Note that working out puts extra stress on your body, and your body needs a good sleep to function; otherwise the other tasks may seem challenging.

A study reveals, not getting proper sleep will negatively impact your athletic performance, and workout in such a situation becomes even harder. So, it is better to sleep well to perform throughout the day.

How to overcome:

If you are constantly compromising on nighttime sleep due to work or any other reason, then you are doing wrong. You are draining out your body which will hamper your health as well.

Lack of sleep has multiple side effects, but you can deal with it if you monitor your sleep schedule. Keep a journal, and record your sleeping and wake-up time. See, how differently your body is performing after a good sleep.

Your body and muscles need rest to recover after a workout session. If you keep ignoring the importance of sleep, then you have to face the consequences in the shape of low or no performance in the gym.

Might Be Iron Deficient

Have you recently eliminated meat and animal products from your diet? If yes, your fatigue could be due to an iron deficiency that your body is struggling with. 

When you are suffering from iron deficiency, your blood has fewer oxygen-carrying red blood cells; therefore, the amount of oxygen that your body receives is limited.

When your body is unable to receive enough oxygen, it cannot function properly. As a result, you experience constantly lower levels of energy. Some other symptoms of iron deficiency or anemia include pale skin, easy bruising, insomnia, and dizziness.

How to overcome:

Keep an eye on your iron levels. If you are vegetarian or don’t like eating meat, you might be in an iron deficit state. When your iron levels are low, the oxygen-carrying capacity decreases. Low oxygen levels during exercise will make you lethargic.

To cope with tiredness due to iron deficiency, you will require a diet or supplements that are iron-rich. You can either get it from plant sources, but its bioavailability is lower than animal sources.

Issues In Diet

If you constantly feel tired after or during a workout, even normal work seems tiresome, then you might be in a nutrient-deficient state. When your muscles are in a calorie deficit state, you are not able to perform well.

Your muscles have different requirements for macro and micronutrients. The muscles are mainly dependent on carbohydrates for their functioning. You must add nutrient-rich food to your diet to deal with all the workouts and routine activities.

Kate Patton, an RD, and a sport nutritionist recommends having high-carbohydrate and protein meals before a workout. It keeps you highly energetic throughout your training.

How to overcome:

If you are not eating well, you may feel sluggish all day even during your workout. It is not surprising, your body requires a balanced diet to function properly.

A study claims carbohydrates in combination with protein work well to keep your blood sugar levels maintained during anaerobic exercise. If your sugar levels are low, you will automatically feel less energetic. Take a good portion of carbohydrate-rich meals to keep your energy levels sufficient during workouts.

Also, you can have some energy drinks during the workout to have a good performance. These drinks have a good amount of vitamins and minerals that reduce oxidative stress in your body.

May Have Hormonal Changes

Hormonal changes in your body may also be one of the primary sources of fatigue. Your body’s production of cortisol, also known as the stress hormone, could cause hormonal change. 

The concentration levels of cortisol decrease during the initial stages of exercise; however, it begins to rise if you exercise for more than an hour.

The overproduction of cortisol in your body may be one of the major causes of tiredness after a workout as the hormone production in your body changes.

How to overcome:

If your body is constantly under stress, you are likely to have raised cortisol. The hormonal imbalance during the workout will make you feel lethargic. To get away with this hormonal change, you need to have proper sleep and a nutritious diet.

Also, if you are dealing with higher cortisol levels, don’t workout daily. Plan your training routine on alternate days.


Constant feelings of panic, worrying, and tension are some of the symptoms that indicate anxiety disorders. When you are trying to work out while suffering from anxiety and worrying about multiple life stressors, you are more likely to be counterproductive.

You must regularly check up on your mental and physical health to understand how your body responds to exercise and workouts.

How to overcome:

If you constantly feel sad or depressed, even during the workout you have some sort of stress or anxiety, you should seek help from a counsellor or have a session with your health coach.

Working out with anxiety will negatively impact your performance. Try to keep yourself happy and in a positive mental state to achieve your goals.

You’re Dehydrated

If you find yourself questioning why your muscles feel weak during a workout, you need to check your everyday water intake. If you do not hydrate properly before and during a workout, you are likely to experience exhaustion and burnout during a workout.

Even the slightest dip in your fluid levels can make your blood thick, so it becomes harder for your heart to pump. By sweating excessively, your body may lose the electrolytes essential for you to power through your workouts.

How to overcome:

During workouts, you are excessively sweating, which makes your body dehydrated. Working out in a dehydrated state will make me sluggish. But you can easily deal with dehydration, keep yourself hydrated. 

Take extra fluids before starting a workout. Also, carry a bottle with you in the gym. You can have some energy drink or electrolyte-rich fluid to keep your vitamins and minerals in balance.

You Need to Carb It Up

If you are working out to lose weight, there are chances that you are not taking enough calories (especially carbs) that are essential to ensure that you have the energy you need to work out.

During exercise, the primary energy source is glucose, the sugar that is derived from carbohydrates. 

If you are usually on a low-carb or carb-restricted diet plan, for example, the ketogenic diet, you may lower your energy levels, especially during an intense workout session, and experience extreme fatigue after a workout.

So bump your carb intake to avoid getting tired after exercising!

How to overcome:

Feeling tired during a workout, a low-calorie diet can be the reason. Maybe you are eating the right amount of calories, but the source is not working well for you. 

So, for better performance and less tiredness, you should have high carbs along with a protein meal. Such meals give you enough energy throughout the workout.

Your Medications Might Be The Culprit

Feel tired during workout

Certain medicines can make you feel popped. They can lower your blood pressure and reduce the blood supply to the brain and muscles. 

As a result, you may experience fatigue during workouts. For instance, medications such as antibiotics and antidepressants can induce symptom fatigue.

It is better to carefully read the labels before taking medication to avoid fatigue that could result in sluggishness during a workout.

How to overcome:

Some medicines interrupt your performance and can make you feel more tired than expected. You can either manage your dosage, or timing with your training routine, or you can consult a doctor for better alternatives.


Generally, everyone feels mild to moderate tiredness during a completely normal post-workout. But, if you feel drained and sluggish throughout your workout, then there is something wrong going on. 

There can be diverse reasons ranging from improper diet to lack of sleep. Your body requires a nutritious diet, good sleep, a positive mindset, and an environment to function properly.

To improve your performance, one must consider your health as a priority and focus on a healthy lifestyle. Incorporate good food sources and supplements to keep your energy levels intact. Align your goals with your trainer and healthcare professional.

Leave a comment