What It Means If You Feel Shaky After a Workout

If you’ve ever felt a little wobbly or shaky after a workout, you’re not alone. Still, it can be unsettling to feel like your legs are about to give out or that your arms have gone soupy. 

And while shaking after a workout isn’t pleasant, the good news is that it’s not usually cause for alarm. Some common causes of post-exercise shakiness include lactic acid build-up as your muscles fatigue, low blood sugar, dehydration, and occasionally too much caffeine, explains Dan Murauski, DO, director of wellness optimization and longevity at Case Integrative Health. 

Keep reading to learn how to combat post-workout shakiness—plus find out more about why it happens and how to prevent it from becoming a recurring issue. 

What Does It Mean to Shake After a Workout?

First things first, let’s get something clear: It’s not uncommon to shake during a workout. You might especially notice it during Pilates or barre classes as your muscle fibers contract and fatigue at a faster pace. You might also notice it while strength training if you lift a heavy weight for the first time or as your muscles start to tire near the end of your reps. In most cases, the shaking stops within seconds of stopping the exercise. 

But when that shaky feeling lasts after a workout, be that a run, ride, or strength class, it means “your muscles have essentially reached their limit,” says Winnie Yu, a physical therapist and certified strength and conditioning specialist based in New York City. “This is your body's warning signal telling you, ‘Hey, it’s time to let the body rest and recover,’” Yu says.

Muscle Shaking vs. Muscle Twitching

While the sensations sound like the same thing, muscle twitching is a little bit different than muscle shaking:

Is Post-Workout Shakiness Common?

You might notice post-workout shakiness more if you’re new to exercise as your muscles adjust to increased activation. For regular exercisers, it may be less common or occur only when you really ramp up your workouts.

“I see [muscle shakiness] more after an endurance workout,” Yu says. “The muscles have been working for a long period of time and, after a workout, they’re still trying to clear whatever is remaining in the muscles.”

What Causes Muscles to Shake After a Workout?

There are a few main reasons your muscles may shake after a workout, including:

1. Muscle Fatigue

When you push your muscles past a certain point, they get fatigued. On the one hand, this is a good thing because you’re strengthening them in the process. On the other hand, it can lead to feeling a little off-balance if your muscles alternate between contracting and relaxing too quickly. When this happens, “your body’s a little shocked from the stimulus and feels fatigued,” Yu says. 

Another reason, says Dr. Murauski, is that your workout may lead to a build-up of lactic acid in the activated muscles, causing your body to rely on anaerobic respiration for energy. This simply means that your muscles’ oxygen needs have surpassed what your body is available to provide, which can lead to fatigue, cramping, and some shakiness. 

And, as Yu mentioned earlier, shaking after a workout can also happen as your body flushes out inflammatory markers, fluid, and waste from fatigued muscles that were just pushed to their limit.

2. Dehydration

When you sweat during a workout, you lose electrolytes, which your muscles need to prevent cramping and function properly. And when you’re dehydrated or your electrolyte levels are imbalanced, your muscles may not contract as effectively, Yu says. “If you’re feeling trembly, weak, or wobbly, this could, again, be your body’s warning to hydrate,” she adds. “It can also be a sign to make sure you replenish electrolytes.”

3. Too Much Caffeine

If you’re the type to exercise in the morning after your coffee, you may experience shaking after a workout simply because your cup of joe’s caffeine can make you feel extra jittery after you perform heart-pounding exercise.

4. Low Blood Sugar

Your body’s main source of energy is glucose, which comes from the food we eat. If you haven’t eaten in a while and those glucose levels are low, you can start to feel wobbly simply because your muscles don’t have enough fuel to keep them going. 

How to Stop Muscles from Shaking After Exercise

Muscle shaking should subside relatively quickly after exercise, and you should feel steady within a few minutes (or no longer than an hour maximum), Yu says. But there are a few things you can do to aid in getting back to baseline as quickly as possible by giving your muscles what they need to recover: 

1. Hydrate

“As you sweat, you lose a lot of salts and other vitamins and minerals,” Yu says. If dehydration is a potential culprit for your shakiness, make sure to hydrate immediately after exercising and replenish electrolytes as needed to get vital nutrients and oxygen to your muscles.

2. Eat Something

Yu recommends refueling within two hours of a workout. “You definitely want to make sure you eat something that has nutritious carbohydrates, but also protein and fats so you’re able to replenish what was just burned during your workout,” she advises.

3. Do a Proper Cooldown

It can be tempting to rush off after a workout, but don’t skip your cooldown, Yu says. “A cooldown is the perfect way to get your heart rate to wind down, and help your entire body return back to baseline,” she adds. “If you skip this, the body remains in an elevated state of activity. Give your muscles time to calm down so that when you move on to the next thing, there's less likelihood of the muscle shaking.” Even if you’re tight on time, squeeze in a few static stretches to wind down. (You can find tons of guided cooldowns and stretching classes on the Peloton App.)

4. Prioritize Recovery

After completing your cooldown, it’s still a good idea to take it easy if you’re feeling shaky. Don’t push yourself into something else strenuous right away. “Muscle shaking can act as a signal to you to lay low the next day or perform a different type of workout in order to rest fatigued muscles,” Yu says.

Dr. Murauski agrees: “Make sure to rest and give your body and muscles time to recover,” he says. “It’s important to listen to your body.” Even if you do feel able to hop back into a workout the next day, focus on an exercise that activates different muscle groups. (So if an intense lower body workout leaves you feeling wobbly, make sure your next session is more upper body focused.)

Can You Prevent Muscles from Shaking After a Workout?

If you’re new to working out or have recently ramped up your intensity, a little post-exercise shakiness may be your body’s way of adapting. But there are a few things you can do to prevent it from becoming a regular occurrence. Dr. Murauski recommends the following:

When to See a Doctor for Post-Exercise Muscle Shaking

Remember, post-workout shakiness should subside fairly quickly. But if hours have passed and you’re still feeling wobbly, it’s time to check in with a healthcare professional. “Within the first five to 10 minutes of a workout concluding, all the natural physiological mechanisms should start to wind down, so if you’re still having an elevated heart rate, or feel shaky or weak hours later, that’s different,” Yu says. 

And no matter how long your shaking lasts, if it’s accompanied by any of these symptoms, check in with a doctor, says Dr. Murauski:

The Takeaway

The best way to avoid shaking after a workout is to make sure you have a plan that supports muscle recovery before, during, and after exercise. That means fueling properly, stretching, and ramping up intensity gradually so your muscles are better able to handle it. If you do feel a little shaky after exercise, look at it as your body is trying to tell you it’s time to rest, rather than ignoring the shakiness or waiting for it to pass. Be proactive about helping your muscles recover, too, so they’re ready to put in the work the next time you exercise.

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.