Let us know if you’ve experienced this: You feel strong and flexible lifting weights. The first few reps feel easy, but each lift requires more and more effort until you can’t continue. It’s your muscles unable to contract anymore — we call this muscle fatigue.
Exercise (in this case, lifting weights) should make you feel energized — not the other way around. But if you’re feeling exhausted after a workout, you’re far from being alone. When you exercise or engage in any workout, you burn calories and use your energy.
Depending on the duration and intensity of your workout, your body will demand hydration, nutrients, and rest to recover. But what can you do about it? And how can you treat muscle fatigue? Read on!
What is muscle fatigue?
It’s normal to get tired, sore, sweaty, or even weak after a workout. There is, however, a limit. If you feel extremely exhausted or unable to move your muscles, it may be a symptom of muscle fatigue.
You’re experiencing muscle fatigue if your muscles’ ability to contract or perform decreases. It is associated with a state of exhaustion, often after a drastic exercise or activity. When you experience fatigue, the movement of your muscles decreases, which will then make you feel weaker.
The common cause of muscle fatigue is exercise, but it’s worth noting that the symptom can be the result of other causes:
Possible causes of muscle fatigue
There are many reasons why our muscles get tired. While we often blame lack of energy and lactic acid for causing muscle fatigue, there are actually other possible causes that trigger muscle tiredness. And clearly, there is no one specific cause of muscle fatigue, but the cause of it will be event-specific.
To understand why our muscles get fatigued, it helps to know the science behind muscle contraction.
Our muscles respond to brain signals that travel through the motor neurons. Between the muscle and motor neurons are tiny gaps that allow the exchange of particles that enable contraction.
When the brain signals for contraction, the pores on the muscle cell membrane open. Potassium from inside the muscle cell membrane flows out, and sodium from outside the muscle flows in. This flow is crucial for muscle contraction.
When muscles contract, the proteins within the muscle fibers lock together to pull the muscle tight. Adenosine triphosphate (a.k.a. ATP; an energy-carrying molecule), gives energy to power the contraction.
With these in mind, we can now better understand the causes of muscle fatigue.
Pushing yourself too hard can cause muscle fatigue. This is true, especially if you engage in a short, high-intensity workout.
ATP is crucial for muscle contraction. If ATP is consumed at a faster pace than it can be made, it causes the levels to drop below resting values. This means you should stop or reduce the intensity of a workout to allow ATP production.
Creatine phosphate is the primary energy source in muscle for ATP. When there are reduced levels of creatine phosphate, an individual will find it difficult to maintain ATP levels. Time and again, depletion in ATP can cause muscle exhaustion or fatigue,
Dehydration is one of the causes of muscle fatigue. Remember, when you’re exercising or engaging in other physical workouts, you lose electrolytes to your body via metabolism and sweat.
Hence, drinking enough fluid is essential to maintain energy levels throughout exercising.
However, drinking water alone will not have the same effect as chugging electrolyte supplements that are designed specifically to help prevent dehydration and retain water.
What you eat always has a huge impact on your muscles’ ability to recover after a workout. When your body is properly nourished, you’re going to feel good every after exercise.
Also, your diet will define your energy levels. Be sure to avoid high-fiber and excessively fatty foods before exercise. Also, carbonated drinks and spicy foods can be tough on the guys and should be skipped.
Generally, the heavier the meal before a workout, the harder it may be for you to recover from it, which would cause you to feel sleepy after your activity.
Other possible causes of muscle fatigue are associated with chronic medical conditions, including anemia, Addison’s disease, electrolyte disorder, chronic fatigue syndrome, hypothyroidism, diabetes, and fibromyalgia.
Muscle fatigue signs and symptoms
The signs of muscle fatigue are observable, while symptoms are those that you can sense, feel, or relate to someone else. It’s essential to know how your body feels so you can easily tell that something’s off and discuss your concerns to your physician.
The most common sign of muscle fatigue is a weakness. You would know your muscles frail when you feel like your legs are very feeble and can’t support your weight.
A great number of reps when lifting weights can also cause muscle fatigue. It’s when you can’t squeeze out another rep or when your muscles feel tired and weaker.
Muscle fatigue can cause your leg to twitch. This commonly occurs after a physical exercise because lactic acid concentrates the muscles during the workout.
The twitching occurs in the myoclonic jerks, which is typical for those who are diagnosed with fibromyalgia. The twitches are caused by nerve impulse signals from the brain that tells the muscles to contract and relax quickly.
You’re in the middle of weightlifting. You feel resilient and robust in the first five squeezes. Then you suddenly feel that you can’t grip the dumbbell tightly enough to perform the last two squeezes. You may be experiencing muscle fatigue.
When muscles get fatigued, you may experience uncontrolled trembling. Trembling or a weak grip may indicate that you are pushing too hard or have exceeded your limit. It’s your muscles’ natural way of protecting themselves.
A good rest should relax the muscles and allow them to recover.
Reduced Activity Levels
Muscle fatigue may also cause your energy levels to drop, which causes you to be unable to complete your activities. This type of muscle tiredness is caused by insufficient blood flow to the extremities.
This is common to those who experience cardiovascular issues: heart conditions and high blood pressure, for example. For most people, the symptoms of muscle fatigue come gradually, making it hard for them to pinpoint the exact cause of muscle fatigue.
How do you treat muscle fatigue?
Muscle fatigue can occur not just to professional athletes, but also to anyone who engages in exercise. It is our body’s way of adapting to a workout regiment. It works like an alarm system that tells you that you’ve reached your limit.
“Know how your body feels so that you can tell if something doesn’t seem right and discuss your concerns with your primary health care provider.” — Denise Stern
The treatment for fatigue depends on its underlying cause and accompanying symptoms. If you experience muscle fatigue that is unrelated to workout, it’s best to consult your doctor. Your health care provider should examine your medical history and symptoms to determine any possible health conditions that cause muscle fatigue.
In most cases, muscle fatigue can be treated with rest and recovery. It’s also crucial to keep your body well-hydrated to improve your recovery time. Maintaining a healthy diet can also help promote healthy muscle function and protect against muscle exhaustion.
Stretching before and after vigorous activity also helps. Doing a quick warm-up can loosen your muscles and protect against fatigue and other injuries. If muscle fatigue persists, you can perform hot and cold therapy to reduce the discomfort.
You can use heating pads and dry heating packs to perform hot therapy. Apply to the affected area to soothe discomfort and improve muscle flexibility. On the other hand, cold therapy (a.k.a. cryotherapy) can help reduce inflammation and swelling, especially around a tendon. It can also reduce nerve activity, which relieves pain.
Of course, we believe prevention is always better than cure. Here are tips that can help keep you from hitting a wall.
- Hydration – drinking water throughout the day can help prevent muscle fatigue, electrolyte depletion, and dehydration. The recommended daily water intake is 10 to 12 8-oz. glasses. Drinking electrolyte-rich sports drinks can also help when during a workout. Water and electrolyte drinks can help replace the water and nutrients that your body sweats off.
- Eating Schedule – eating a snack or light meal a couple of hours prior to your workout can help. It’s not best to engage in physical activity with an empty stomach or a full stomach. Eating within an hour after your activity can help repair and refuel the muscles that were worn out during exercise.
- Nutrition – a well-balanced diet that includes complex carbs, veggies, fruits, and complex proteins are essential for preventing muscle fatigue. Eating right will help maintain the glycogen levels of the muscles, which get depleted during exercise.
- Rest – performing a warm-up and cool down for 5 to 10 minutes each time you exercise can help avoid you from muscle tiredness. Start slow and progressively increase your workout intensity levels, so your muscles are challenged over time.
A quick rest between workout sessions and reps can help the muscle recover the ATP lost. Listen to your body. Again, fatigue is our body’s way of telling us that we’ve reached our limit. So if your muscles feel weak and tired, give yourself some time to breathe and relax. Do not engage in high-intensity exercise until you feel fully recharged.
Muscle fatigue decreases your muscles’ ability to perform actions. It is a normal body reaction that tells us our body needs to recharge. It is usually exercise-induced and often considered no cause for alarm.
However, if the fatigue persists and doesn’t improve with rest, it can be a symptom of other more serious medical conditions. It’s best to schedule an appointment with your doctor.
Always listen to your body. If something seems a bit off, take a rest and do not overwork your muscles. Adequate rest should help your muscles recover and recharge. Drink plenty of fluids, maintain a healthy diet, and focus on your nutrition.