Two days later, "my arms literally looked like Popeye," she said. She could barely lift or straighten them, and the pain was excruciating.
She went to the doctor, who told her she was suffering from rhabdomyolysis, a rapid breakdown of muscle fibers into the blood stream. (Along with muscle pain, weakness and swelling, tea- or cola-colored urine can be a symptom.)
Untreated, it could have led to kidney damage, or even kidney failure. As it was, it scared the heck out of her.
Rhabdomyolysis is rare, according to sports-medicine specialist Dr. Michael J. Ross, of the Rothman Institute. Too much exertion, too little vitamin D and heat are all risk factors, he said.
But the fact that even a well-conditioned yoga instructor can come down with such a thing is something to keep in mind when you're trying to amp up your own workout.
Overexertion can also cause sprains and strains (and even stress fractures), muscle pain and a cousin to rhabdomyolysis called DOMS (for delayed-onset muscle soreness) that's characterized by pain and stiffness that comes on 24 to 72 hours after a workout and can persist for a week.
Bottom line: Extreme workouts can be dangerous, so always listen to your body, first and foremost.
Labored breathing, dizziness, fatigue, muscle cramps, headache, nausea, chest pain and an elevated resting heart rate are some signs that you may be overdoing things. If you're breathing too hard to talk comfortably, take that as a hint to slow down.
People who are regularly pushing themselves too hard may also have muscle aches and pains that don't seem to go away, frequent or recurring colds and a general lack of energy and motivation.
Never let some pushy commando-style trainer push you over the edge into the danger zone. If you feel like it's too much to handle, don't do it - period. Luckily for her, Conroy didn't suffer permanent damage.
Kimberly Garrison is a wellness coach and owner of One on One Ultimate Fitness in Philadelphia. Her column appears Wednesdays.