"Being slim and fit are two different things," says Michelle Lovitt. You can be slender and out of shape, with brittle bones and in poor cardiovascular health. "When I work out with Lady Gaga
, we try to create lean muscle," says her trainer, Harley Pasternak
, noting an added benefit: Most people noticed that they have more energy when exercising regularly.
Heartbeats by Lady Gaga headphones, $100; bhphotovideo.com