Lions star wide receiver Calvin Johnson shared one part of his pregame routine Thursday. Before each game, he throws in a yoga video and has a good stretch before heading to the field. It’s not Bikram yoga or anything heated — though Johnson has tried that, but rather simple exercises that stretch any areas that have been bugging him. “If I need to work on my hamstrings, if I need a full body deal or if I just need to work on my hips, whatever needs work,” Johnson said. “Nothing crazy. We’ve got a game to play. (I’m) just trying to loosen up.” Yoga has become increasingly popular among NFL players in recent years, Lions cornerback Rashean Mathis said. He’s done yoga for the past four or five years and said the Lions strength and conditioning coaches recommend it. “We had yoga instructors come to the facility sometimes in Jacksonville,” said Mathis, who spent his first 10 seasons with the Jaguars. “It’s a way to stretch yourself and get loose and knock out the kinks and the tightness of your body without overdoing it in the weight room. It’s a good thing to get into.” The myth that yoga is just for women has been disproved in recent years, and several high-profile professional athletes participate in the exercise, including Miami Heat forward LeBron James. Johnson started doing yoga a few years ago when quarterback Drew Stanton was still on the Lions. Stanton’s wife was a yoga instructor, so he and the backup quarterback would do yoga at Stanton’s house. Although the stretches were tough at first, Johnson said it’s become easier now that he does it regularly. “I’ve seen definitely a positive impact just from being loose in my hips, my hamstrings,” he said. “I know it’s something that works for me, and I’ve just been doing it ever since.” The Stantons also had a heated room where they could do hot yoga. Now, though, Johnson just does it by himself without any heat.