There’s a rite of passage when you start a new exercise routine or sport: following your workout, parts of your body may wobble like jelly.
While this experience can happen even with pros, Andrew Jagim, an exercise physiologist at the University of Wisconsin, said that “jelly legs” are especially common with beginners who are not used to working out.
“Even doing body-weight squats for five minutes could be enough to make their legs start shaking and quivering,” he said.
Even though this is a natural physiological reaction, it’s still something you’ll want to watch. Unsteady muscles after you use your maximum effort are part of your body’s cry for some rest.
From an athletic trainer’s perspective, the signal means: “Hey, it’s time to sit down. Don’t go hurt yourself,” said Patrick Maloney, the lead athletic trainer at Tulane Institute of Sports Medicine in New Orleans.
When this physical shakiness occurs, it means your nerves are short-circuiting and are having trouble communicating with your muscles, Jagim said, because of the rapid onset of fatigue your training is causing. So your body “can’t initiate muscle contraction and relaxing like it normally does,” Jagim explained.
It’s “a temporary state of fatigue, and it’s largely due to the disruption to just how our nervous system and muscles can communicate with one another,” Jagim said.
Your muscles are fuelled by different types of energy stored in your body, depending on your workout, Maloney said. “The reason that your muscles are getting shaky and they’re unable to produce that high-quality contraction is basically they’re low on energy,” Maloney said. “You’ve exhausted all of your storages.”
Some fitness regimens recommend doing as many reps as possible, which can make your muscles feel shaky. “If you’re trying to achieve max weight you can lift or max speed, you want to approach those thresholds” that can cause a jelly-like muscle reaction, Maloney said.
But know that it’s not necessary to do this to get fit. “It’s not something that’s absolutely needed for you to get stronger or get faster or see improvement,” Jagim added.
‘Jelly muscles’ can be normal but prolonged shakiness or pain is not. Here are some red flags that need further attention.
Some shakiness is typical for beginners, but there’s a critical difference between your muscles feeling like jelly and feeling sore and hurt days after your workout.
If your muscles are swollen, your skin is feverish or you are peeing brown urine a day or two after your intense workout, you’re experiencing strong indicators of an intense kind of muscle damage known as rhabdomyolysis, Jagim said.
In this scenario, “the muscles incurred so much damage during that workout, it’s leaking ammonia and other kind of protein byproducts into the bloodstream, and it’s starting to impact like liver and kidneys,” he explained. Jagim said this can happen when a sedentary person tries to do an intense workout that is too much for their muscles to tolerate.
If you have any of these symptoms, seek medical help immediately.
And if you’re feeling weak and shaky after a workout, the best and quickest way to get back to normal is to take a short break. Maloney said people typically stop shaking after about 10 minutes.
Jagim said you don’t necessarily have to end your workout, either. Simply switch up your exercise. If your legs are quivering, do some pushups, which work a different set of muscles. “Sometimes by the time you get back to a leg exercise, you’d be ready to go again,” Jagim said.
One word of caution: if you are lifting heavy weights and your muscles are wobbling like jelly, don’t test your limits without supervision. “It can be dangerous,” Maloney said. “If you’re lifting weights over your head … you can drop a weight on your head.” He suggested having a spotter with you, so they can intervene if needed.
If your legs are shaky, for example, “the last thing you want to do is load up a lot of weight on the bar, and then your legs give out,” Jagim said.
The good news is that the more you train, the more your body gets accustomed to your high-intensity workout. “These metabolic pathways will get more efficient and stronger to where eventually you don’t experience this feeling,” Maloney said.
“If you were to do that same workout again in a couple days … you probably wouldn’t feel that sensation anymore,” Jagim said. Once someone becomes “more accustomed to their workout routine,” he added, “I would say it’s actually quite rare for people to get to that point where they really feel that jelly-like sensation.”
