EAST RUTHERFORD, N.J. — In 2011, a new N.F.L. labor agreement did away with a staple of summer pro football workouts since the 1950s. Gone was the punishing two-a-day practice regimen.
With it went dozens of full-contact sessions in preseason training camps because another new rule restricted the number of days players were allowed to wear all of their pads. At many N.F.L. camps now, it is rare to see any player tackled to the ground. Many practices resemble aggressive touch football games.
The objectives have been to prevent head trauma and other injuries and to limit the wear and tear on bodies.