If you have a disproportionate physique there are numerous possible causes, however I will focus on the cause that is most probable. The number one contributing factor to a disproportionate body part is lack of direct exercise to that specific body part. A good example of this is when an exerciser only exercises his or her arms and forgets (or chooses) not to exercise their lower body. What happens over time is the arms get well developed but the lower body remains as it was before and completely untrained. To develop a good overall solid physique all major muscle groups must be trained on a regular basis. My advice is train all major muscle groups a minimum of once per week and a maximum of twice per week if you are advanced and capable of quick recovery. The major muscle groups include chest, shoulders, back, arms, quads, hamstrings, calves and of course abs. If you can manage to train all these body parts once to twice per week you will be well on your way to developing a good solid well rounded physique.
In the event you have been training your entire physique for an extended period of time but still have lagging body parts then it’s time for a refresh. The best strategy to overcome roadblocks when it comes to developing lagging body parts is to hit them with heavier weights and more sets. The extra challenge will force the muscle group to adapt and growth will soon follow. Continue to vary your exercises on a bi-weekly basis and remember the phrase, if you don’t use it you lose it. Stay focused, continue to train and remember that lagging body parts can be brought up to speed they just need a little more attention and focus to get them to respond.