It’s very hard for a man to serve two masters. The goals and means to reach these goals will often be different, which could result in not only wasted efforts, but an inability to complete either goal. This happens in bodybuilding all too often. Trainers believe they can use mass-building movements such as squats to build up the legs. They also believe they can use frequent cardio training to shed unwanted body fat. They attempt to complete both of these goals at once. As a result, they often end up completing neither, and wasting their efforts.
The problem exists because many bodybuilders need to complete 4 to 5 sessions of cardio each week to remain lean. In doing so, they invariably derail some gains to their leg mass. It’s very tough for the bodybuilder – particularly the natural trainer – to make muscle gains while shedding body fat. Ideally, the bodybuilder looking to make gains in leg mass shouldn’t be doing much cardio at all. Cardio is intense, and results in a devaluation of the resources of the central nervous system, as well as in recovery of the leg muscles.
If you MUST do cardio work each week, for leanness or health purposes, you should be aware that it will be very hard for you to make any notable gains in terms of thigh mass when you are forcing your legs and central nervous system to face down a series of 4 to 6 training sessions each week. The legs are a very large muscle group, and therefore do not recover all that quickly. Training them with weights breaks down a number of fibers. It is when the legs are allowed to rest and heal, amongst a surplus of calories and plenty of amino acids present, that growth can occur. Multiple intense or long-lasting cardio sessions each week tend to remove this rest period. The legs are in a state of perpetual soreness. This may allow the trainer to shed unwanted body fat, but it will also lead to thighs that lack any true size.
Reorganize your goals. If you are currently sitting at an excess of 15-18% body fat, it would probably be a good idea to first shed some body fat and get your physique down to a more palatable 12 to 14% body fat. From there, you can embark upon a ‘clean bulk’ program, where you back off the cardio and really focus upon making gains in lean leg mass.
In bodybuilding, it’s all about leaving it all on the gym floor. When you complete your workout, you should be completely spent. If you have the goal of making legs grow, then you should train them and then feed them every possible resource (food, sleep, supplements, and potentially AAS) to make them grow over the following week, until the next weight session. If your goal is to become lean, you should focus only on retaining the leg mass you currently have. Keep your goals clear, and the gains will follow!