You’ve probably felt your muscles shake at some point during a hard workout. At first, it can be alarming — you’re literally vibrating like a bell that’s ringing for you to halt whatever it is that you’re doing.
You might wonder: Is it normal for my muscles to momentarily quiver out of control while holding this plank? Is my infrastructure in danger of collapse?
The short answer is no, you’re good.
While you may crumple to the mat, you’re likely not destroying your foundation but rather reinforcing it. That little muscle quake is generally a good sign that you’re pushing yourself and getting stronger for it.
“If somebody is doing a challenging new activity — say a weighted split squat — it’s not uncommon to see them shake,” explains Trevor Rappa, a doctor of physical therapy and co-founder of Resilient Performance Physical Therapy in NYC. “The reason behind that is our brains have these motor patterns that execute on command, like walking. When we introduce something new, the brain needs to figure out how to do it. Some muscles may not know how to work in conjunction with others to perform something new, which can cause some of the shakeup.”
This doesn’t just apply to people who are upping the ante in their fitness routine. If you’ve taken a hiatus from the gym (long or short), reintroducing exercise to the body can be jarring. “For someone who hasn’t trained in a while, exercise really disturbs their homeostasis,” Rappa says. “Any disruption to that baseline is going to be a shock to the system, so it’s not abnormal to have that shaking response.”
Another factor that may add an extra twitch (or 20) is fatigue. If you’re on your third set of minute-long planks, it makes sense that you’d be feeling wobbly. “When the muscles get really tired and heavy that’s often due to an accumulation of hydrogen ions, making muscles more acidic,” Rappa says. “That sends signals to the brain that the muscles are in pain or have a lot of discomfort, which then prompts the brain to tell the body to stop.”
The good news: Your body’s involuntary mid-exercise convulsions will eventually subside as you grow accustomed to the moves and develop your strength and conditioning, says trainer Noam Tamir, founder and program director of TS Fitness studio in Manhattan. In other words, getting in shape may delay the onset of this fatigue. “More conditioned people usually have better nerve recruitment so they don’t lose control as quickly,” Tamir says.
BUT KNOW WHEN TO BACK OFF
There is a balance, however, of knowing when to push through versus when to hold back, like when you feel the tremors rising. “Shaking isn’t dangerous, but it could be if you are holding weights that you can’t control and put force on muscles and joints that have lost their power,” Tamir warns.
Rappa agrees but emphasizes that context matters. For example, if you’re feeling unstable doing lunges, adding a light weight might help you feel more grounded and allow you to regain balance, he says. However, if the weight is too heavy, it could throw you off balance, which could lead to injury.
AND REMEMBER TO BREATHE
One way to safely work through muscle quakes is to keep breathing. Holding your breath while planking will only add stress to the body and make you shake more, Rappa says. Instead you want to encourage the body to relax, which you can do by exhaling and inhaling at somewhat of a normal rhythm. “Reset your breathing cycling, and you may stop shaking,” he says.
After your workout, make sure to replenish your glycogen stores with muscle-building foods (such as these tasty options) within the recovery window of 30 minutes after completing the activity. Adequate post-workout recovery will help you come back fresher and stronger next time.