When considering rewards for effort within a team it is important not to overcrowd the intrinsic motivation with extrinsic motivations. If a person or team is motivated to achieve and do well and this motivation comes from within then to add further extrinsic awards crowds out the intrinsic motivations and in fact can be demotivating. So better to focus on an element of work that is not performing well and that people are not feeling motivated to achieve in. In our team, this could relate to fitness or health standards.
The question then is how to improve health and fitness through a fun and motivating way. We previously had the Biggest Loser campaign and this worked well with some people. These people were probably already motivated to change and so were already intrinsically motivated. The best way to improve the level of health and fitness is to perhaps provide a fun experience for participants – a way of them getting them to be active without thinking about it.