John Cena's 2015 will likely be remembered for his incredible U.S. Open Challenge, where he defended the United States Championship on a near-weekly basis, proving that no matter which title he holds, he is a fighting champion. The Cenation leader has also appeared in a few major films this year, including the Golden Globe-nominated "Trainwreck" and the hit comedy  "Sisters." He's also the host of an upcoming reality competition on Fox called " American Grit." Now, Cena caps off his incredible year and starts 2016 with another accomplishment — an incredible cover feature for the January 2016 issue of "Muscle & Fitness."

Of course, Cena has been featured on the cover and inside of the prestigious fitness magazine before, but this most recent examination of the 15-time World Champion delves deeper into Cena's passion and what continues to motivate him. As he explains in the feature, self-improvement and striving to be better is what keeps him going. Cena reveals in the feature that he has been learning Mandarin so he can talk to WWE fans in China.

"The moment you think you've made it, you're done. That's when you need to go fishing," Cena told "Muscle & Fitness."

In the feature, Cena also discusses his workout and how it's evolved over the years alongside his in-ring career.

See the full cover feature in "Muscle & Fitness," on newsstands now.