"Just a lot different, honestly," he said of how he was feeling post-procedure, per the Associated Press (h/t ESPN). "Energy. Even cardiovascular workout capabilities. Done some [Peloton] rides I haven't done in a few months that I didn't even realize, oh, this is what it's supposed to be like."
Boone added that he still has some limitations following the procedure.
"Still have some arm restrictions," he told reporters. "So I can't like lift weights like I normally do, but that will be hopefully a few more weeks. But as far as just getting around, energy in the mornings and all day, so much better."
The 48-year-old had open-heart surgery in 2009 during his playing days due to a swelling of the aorta and had yearly checkups to monitor his heart. This year, after being monitored for several weeks, however, it was found that his heart rate was dropping to 30 to 39 beats per minute.
Most adults have a heart rate between 60 and 100 beats per minute. His new pacemaker should help normalize his heart rate.
"I'm really, really thankful and grateful that we were able to identify it and it went kind of as they told me it would," he said. "I was very at peace and comfortable with getting it done. They told me you'll notice a big difference. Until you go through it and experience it, I guess you don't realize how much of a difference you notice."
Boone was hired as the Yankees manager in 2018 and went 236-148 in his first three seasons, leading the team to three straight playoff appearances.
Before his managerial career, he played 12 major league seasons with the Cincinnati Reds, Yankees, Cleveland, Florida Marlins, Washington Nationals and Houston Astros, hitting .263 with 126 homers and 555 RBI. He was an All-Star in 2003.