MINNEAPOLIS — Joe Berger remembers the feeling. It was February 2005 and Berger, along with hundreds of other N.F.L. hopefuls, was at the combine, the league’s annual scouting carnival. Many of the players were nervous or anxious, fretting about their bench-press repetitions or their sprint times. Berger, on the other hand, mostly felt bloated.

“I just never stopped drinking,” he recalled recently. “I chugged everything. Gatorade, water, whatever — all I wanted in life was to make 300 pounds.”

Buoyed (and admittedly somewhat distended) from his hyper hydration, Berger did, in fact, swell to 300 pounds — “303!” he said — which, for a college lineman looking to play in the N.F.L., was the generally accepted bare minimum. But since then, while his colleagues on the line have often ballooned to weights closer to 320 pounds or more (yes, sometimes a lot more), Berger has stayed put. Now in his sixth season with the Vikings and 12th professional season over all, Berger proudly still weighs 305 pounds.

“One year I tried going up to 320,” he said. “It felt like I was in a fat suit. I couldn’t move.”

As a result of enhanced nutrition techniques, changing offensive styles and adjustments to football’s rules, Berger and his brethren of undersize linemen appear to be a growing demographic in the N.F.L. And they are generally happy to embrace their roles as the pygmy elephants of their sport, the baby grand pianos of the game: little, but not that little.