When you exercise, you challenge your body beyond its normal limits, which gets your heart pumping and your lungs working to circulate air throughout your body. Lifting weights adds an extra challenge to your muscles -- and if you experience some muscle shaking after exercising, it can be an alarming sign. Body shaking can be a typical aftereffect of strenuous exercise, but you can take preventive measures to reduce after-exercise shaking.
When you lift weights, you challenge your muscles and create tiny tears in the muscle fibers. Your body repairs these muscle fibers, which helps to improve your muscle tone. However, when you lift weights at a strenuous pace or lift very heavy weights, your muscle fibers can become fatigued. As a result, you may lose some control over the muscle fibers, which leads to shaking. This shaking can affect any muscle group, but for weightlifters, it is commonly experienced in the leg muscles, including the calves and thighs. However, you may experience shaking in the arms and hands as well, particularly after you perform bicep curls, shoulder presses and triceps dips.
Your muscles rely on mineral balances, including potassium and calcium, to contract and relax. When you lift weights, your body uses these minerals and sweating can increase the release of these minerals. When you lift weights intensely, your muscles may use these minerals more quickly than normal, which can result in twitching and spasms that lead to muscle shaking.
Preventive techniques to avoid body shaking after lifting weights can include drinking plenty of water to avoid dehydration, which can lead to muscle cramps or spasms. If you lift weights longer than an hour or lift in hot temperatures, consider drinking an electrolyte-containing beverage, which contains minerals needed to maintain muscle function. Changing up your regular weightlifting routines, such as working your arms one day and your legs the next, can eliminate the muscular overload that causes you to shake.
While shaking muscles following exercise are not typically causes for concern, in some instances they can indicate the need to see a physician. This includes muscle shaking that is severe or leaves you unable to control your limbs. If your muscles shake more severely over time or repeatedly coming back after you take preventive measures, you also may need to see a physician. Muscle shaking that does not subside with time also indicates a more serious condition. Conditions that can cause uncontrollable muscle shaking include compromised kidney or thyroid function.