First, congratulations on exercising five days per week! Most people find working out at that frequency extremely challenging and you have managed to overcome the barriers to keeping that commitment, which is remarkable on its own. Second, you could be experiencing the effect of consistently performing an exercise program that suffers from lack of variety. When you exercise using only one modality (e.g., elliptical machine), the body becomes very efficient at using only those muscles required for the activity. For example, you mention that you seem to have overdeveloped your upper hips, which supports the point that performing only one type of exercise stresses only a select few muscle groups consistently. Even more important, the muscle imbalance you may be experiencing could be setting you up for injury.
Working only certain muscle groups with high-volume training (e.g., five days per week) predisposes the muscles and bones to repetitive overuse injury. To prevent this, consider incorporating cross training into your daily workout plan. Cross training consists of adding other types of exercise to your existing program to help you achieve your fitness goals with a reduced risk of overuse injury. For example, for aerobic training, elliptical-machine exercise could be combined with walking, cycling, and swimming on alternate days to challenge the musculoskeletal system in a variety of ways. This format would allow you to achieve your cardiorespiratory fitness goals, while simultaneously working the muscles in several unique ways. Overall, this approach will work to improve your overall fitness as well as add variety to your exercise routine, which could result in more motivation and adherence to the program.
Source: http://www.acefitness.org/acefit/fitn...
