People new to weightlifting often think they should just fight through pain. “That type of mentality isn’t beneficial in the long run. It will catch up to you,” says Chris Matsui, the director of Fusion Performance Training in New York.

Injuries occur most often when people push for extra repetitions and sacrifice technique, he says.

When learning a new weightlifting exercise, start with light weights and build up, he says. On a scale of 1 to 10, aim to find a weight that challenges you at the 5 or 6 level. A person should be able to do about 10 repetitions without sacrificing technique if the weight is right.

Proper form involves the entire body, not just the muscle targeted.

When bench-pressing, for instance, “place yourself in the strongest position to be able to drive off,” he says. That includes a slightly arched back, abdominal muscles held tight and the upper back on the bench. People have a tendency to line their elbows up with their shoulders when lowering the weight, but they should remain close to the body, Mr. Matsui says.

Significant increases in weights should happen over weeks and months, not days, he says. The number of repetitions can decrease if necessary to maintain form.

Click for more from the Wall Street Journal.