In my opinion, the
muscle groups that will
lack the most and would benefit from modifications in the program would be the biceps, triceps, hamstrings, rear delts, traps and
calves.
Runners and cyclists tend to get tight
calf muscles through over-training and
lack of stretching, but they're not alone, many people have some degree of tightness in their
calves because we spend a lot of time seated.