You expect to sweat during a hard cardio workout or to feel your heart pick up its pace, and maybe your muscles become a little sore afterward.
But sometimes your body does something unexpected. You shake, feel dizzy or otherwise experience a physical symptom that seems out of the ordinary. Should you worry — or is it simply part of getting in shape when you’re over 50?
We talked with experts about the six most common workout side effects, what’s a normal part of exercising and when it’s time to seek medical help:
1. Your shoulder clicks
A clicking noise in your shoulder when you raise your arm up or out to the side may seem alarming but is actually very common, especially as we age, says Dr. Russ Petrie, orthopedic surgeon with Hoag Orthopedic institute, Irvine, Calif.
“Sometimes this happens earlier in life, others later. But most importantly, the clicking or popping should not be accompanied by pain,” notes Petrie. He says it’s often hard to determine the cause of the sound, but can be due to minor scarring in the bursa area or simple wear and tear of the tendons in the shoulder.
If you experience shaky muscles after your workout, it may be a sign your blood sugar is running low.
— Irv Rubenstein, exercise physiologist
If it causes pain, keeps you awake at night or the pain does not go away within 48 to 72 hours, Petrie suggests scheduling a medical evaluation.
2. Your knees crunch when doing lunges or squats
Blame breakdown of cartilage under the knee cap for the crunchy sound your knees make during a set of squats. This can also start early or later in life, says Petrie.
“The resulting grinding-like sensation is not usually a problem when there’s no pain along with the sound. However, doing deep squats, particularly with added weight, can accelerate the process and over time and lead to further damage and even arthritis,” he notes.
Running and jumping activities increase the risk. If the grinding is painful seek medical attention. But rest assured almost everyone develops some during their life, says Petrie. “If your knee ‘locks,’ where the knee cannot be moved without pain, it should be evaluated further,” he adds.
3. Your muscles shake
Shaky muscles can occur during your workout or afterward. “The cause depends on when it happens,” says Irv Rubenstein, exercise physiologist and president of S.T.E.P.S., a Nashville, fitness training center.
“If you experience shaky muscles after your workout, it may be a sign your blood sugar is running low. Your body may not be used to using glycogen (stored glucose, or blood sugar) for work,” says Rubenstein.
When your muscles shimmy and shake while lifting weights it’s actually a form of tetany, or spasms, says Rubenstein. “It’s what happens when a muscle can’t quite relax,” he adds. Twitching muscles during an isometric exercise such as a wall squat are likely fatigue-related, Rubenstein adds.
“In either case, it’s not dangerous,” says Rubenstein.
4. You’re short of breath
Pushing hard on cardio can make you feel fatigued and short of breath and is a normal part of building endurance, says Dr. Aidan R. Raney, interventional cardiologist with St. Joseph Hospital, Orange, Calif. “But if you’re doing an activity you’ve done in the past without this same symptom, it could signify a heart problem,” Raney says.
Pay heed especially if the symptom is also accompanied by chest pain or pressure, palpitations, lightheadedness or nearly passing out. If you experience any of these issues, seek a medical evaluation, which includes a supervised stress test to monitor your heart’s activity and ensure it’s functioning properly.
5. Downward-facing dog gives you indigestion
Eating or drinking too close to a workout that involves downward positions, such as some poses performed in yoga, can cause feelings of indigestion.
“You should avoid eating for an hour before a workout,” says Dr. Oren Zaidel, gastroenterologist with Torrance Memorial Medical Center, Torrance, Calif. “In some cases, however, indigestion may be caused by a hiatal hernia (weakness of the lower esophageal sphincter that allows the stomach to herniate into the chest cavity).”
Zaidel suggests trying over-the-counter antacids 30 minutes before the workout. If you continue to have symptoms, consult your gastroenterologist for advice and to discuss the potential need for tests.
6. Your spine cracks when you bend or reach
Experiencing a popping or cracking noise in your spine may sound scary but it’s not much different than popping your knuckles, says Dr. David Geier, orthopedic surgeon in Charleston, S.C. “The sound comes from the joints in the spine.”
Unless the cracking becomes painful or is accompanied by numbness, tingling or weakness, you’re likely fine. See a doctor for an evaluation if these other symptoms occur, however, says Geier.