Good idea, I may make that change when I do the full fitness/weight loss system revamp.
Cool that you like the idea,
Very much looking forward to that revamp.
Treating weight and fitness seperately but with certain connections is probably a good idea. Other games do that by distinguishing between "cardio" training to lose weight and "strenght" training to build muscle/fitness.
Sure you have some additional ideas up your sleeve.
regards,