Rashad Jennings’s Inimitable, Elaborate Pre-Game Dance

East Rutherford, N.J. — Now in his seventh year in the N.F.L., Giants running back Rashad Jennings has developed an inimitable, elaborate 25-minute pre-game routine that is part performance art, part plyometrics and part flexibility training. It involves dance moves, stretching and atypical agility drills that have Jennings hopping, high-stepping, skipping, bobbing, twisting and crawling – all of it mixed in with the occasional moment of quiet meditation.

On a football field crowded with players getting ready for the game by throwing, catching and kicking footballs in seemingly every direction, Jennings’s odd, solitary warm-up in one corner stands apart. Although recently, some of his…