It seems that not everyone thinks so, and it may not help so much in certain sports like the marathon.

Several pithy quotes from the article:

And don’t worry about becoming too muscular, Dr. Kraemer said. “The
fear of getting really big is not plausible for most people,” he said.
Competitive distance runners and cyclists, who are naturally slender
and light, “don’t have the muscle fiber number to get really big,” Dr.
Kraemer said. “I can train them until the cows come home and they are
not going to have big muscles.”

The main problem with weight lifting is that many people do it all
wrong, said Kent Adams, the director of the exercise physiology
laboratory at California State University
at Monterey Bay. They don’t have a program or a goal. Technique may be
sloppy. Or, Dr. Adams said, they use weights that are too light.
Muscles need to be stressed if they are to respond, he said. Dr.
Kraemer is on the same page. One study, he said, found that women tend
to lift half or less of what they could lift. And this happened even
when women were working with personal trainers, he said. “There
is so much misinformation,” Dr. Kraemer said. “It’s a quagmire out
there.” He recommends trainers certified by the National Strength and
Conditioning Association, which also supplies educational information.
Dr. Kraemer is a past president of the organization.

Technorati Tags: weight lifting, exercise