After a lackluster showing in spring practice last year, Langley got a little lecture from Tennessee's defensive tackles coach Dan Brooks.
"Coach Brooks sat me down and told me the key to my preparation after spring practice was to lose weight and work on my flexibility," Langley said. "You take what Coach Brooks says to heart because he's the best guy in the business.
"I lost weight and worked on flexibility, and this spring you can tell the difference. Coach is telling me all the time it's like night and day."
Having shed 20 pounds in 12 months, Langley believes he's a much better athlete at 285 than he was when he was tipping the scales at 305.
"I feel a lot better," he said. "I feel a lot quicker. I feel a lot more confident, too. The weight loss shows up the most on the pass rush and stamina."
Langley's continued development could be a huge key for the 2008 Vols, who desperately need better play from the tackle position than they got in 2007.
Although he isn't an imposing physical specimen, Langley more than offsets his lack of size with a full-throttle motor. Phillip Fulmer has noticed.
"I see Donald giving really exceptional effort, and that's encouraging," the Vols' head man said. "We just need more production."
Langley's production was pretty significant last Saturday in the Vols' first full-scale scrimmage of the spring. He led all defenders with five stops that afternoon.
"Yeah, that felt pretty good," he said, grinning at the recollection. "Once you get that first tackle out of the way and you put that smile on your face, you have more confidence and more energy and you go a lot faster.
"Once Coach Brooks says 'Good job, Donald' and gives you a pat on the butt, it makes you want to play hard and show the coach what you have."