Push-ups are, at-best, a difficult exercise to get right (see http://thetoptwoinches.wordpress.com/2007/12/04/100/). Do them in bad form and you can injure yourself. Is the team leader going to be both an expert at management AND an expert at physical education? Does the company want the lawsuits if an employee is injured exercising at the direction of their team leaders? Are investors aware that their money is being used for this stuff?
Oh, and considering this stuff is not related to the job at hand, you could also argue for a discrimination lawsuit considering it's creating a "hostile work environment" for anyone without a lot of shoulder strength (women, old people, the disabled).