• Rangers Spring Training info
"It's just a fun way of doing some cardio and footwork," said Fielder, who played in only 42 games in '14 because of neck surgery and rebounded last season with a .305 batting average, 23 home runs, 98 RBIs and an .841 OPS in 158 games.
"Obviously, if you punch somebody and you're not squared up right, you'll be off balance and they could probably hit you back. Thank God the punching bag won't do that, but you try to imagine it."
Fielder said he got some of the inspiration for bringing the bags to camp from his son, Jaden, who has trained with mixed martial arts and jiu-jitsu.
"He's just really good at it," Fielder said of his son. "It just came natural to him. He'll use a couple elbows. He's pretty good."
Fielder admits that he has been entertained by watching some of his teammates take a crack at the bags, since the workouts are notoriously taxing and the rhythm of the spinning speed bag is tougher than it seems.
"A lot of guys, when you see them punch, you're like, 'Wow. I'm glad you've never been in a fight,'" Fielder said. "I've actually built up endurance for it, but it's a workout, for sure."
Fielder said he's been doing boxing workouts for two years.
"Whenever you hear boxing, it's always about footwork, with the jump-rope stuff they do," Fielder said. "It's just a fun way to burn some calories and get better, using your core. It's better than a treadmill."
Rangers manager Jeff Banister said he has no problems with it.
"If it works for him, I'm good on it," Banister said. "One of the first things my dad ever did in that little bitty garage where we lived -- and you couldn't even get a car in there -- he put up a speed bag and a body bag and tether ball, and worked with that.
"It's the hand-eye coordination, it's the hand quickness, it's the balance. I'm OK with it. Plus, I might need him by my side."