When British trainer Steve McGregor (above) began working with Rory McIlroy in late 2010, McIlroy had "untapped" fitness potential, says McGregor, 39, who also helped whip Lee Westwood into shape. "I measured his muscle strength and saw imbalances." McIlroy's left side, from his back through his legs, was weaker than his right, so McGregor devised a plan to remedy that. Here, in McGregor's words, is a behind-the-scenes look at McIlroy's muscle makeover.
"Rory works out five times per week, 90 minutes per day. We don't give [regimen] specifics -- he sees his fitness as part of his competitive advantage. But we train indoors, outdoors, with weights, on the treadmill, doing sprints, and he swims when he's near the beach. Rory stuck to his workout at Kiawah, even though it was a major. He has great commitment."
"Rory's never lacked for confidence, but there's a lot of scientific evidence that links being strong and physically fit with self-confidence and psychological well-being. Those are great things to have on the course."
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"He had issues with his back in 2010. He was only 21 then, but he'd been swinging a club since the age of two without much focus on fitness, and that created an overuse injury. We pay special attention to keeping his back strong."
"The benefits? His clubhead speed has increased, he's driving it longer. He can hit it harder without losing balance. He looks more stable in his swing, and he's getting more yardage with less effort."
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"We've added muscle mass. Rory weighed 160 pounds [in 2010] and is now 170. That's a 20-pound change in muscle composition, when you take into account loss of body fat. And he's not done. He's not where he wants to be. He sees himself as a golfer and an athlete. We're talking about getting to 175 pounds or more. Why? When you increase muscle mass, you're going to be hitting shorter irons into greens."
"It's important to vary your workout, to stay fresh but also not to overuse certain muscles. We vary his workout every 6 to 8 weeks. Everything we do relates to his golf. Our goal is to keep him physically robust, so that his body can stand up to hitting all those shots, and so that he can practice as much as he wants."
This article originally appeared in the December 2012 issue of Golf Magazine, on newstands now. Click here to subscribe to Golf Magazine and to learn about Golf Magazine All Access.