Lean muscle tissue is metabolically active tissue because it possesses the sub-cellular organelle called the mitochondria. These structures are where cell respiration occurs; therefore, more lean muscle tissue = increased number of mitochondria = increased resting metabolic rate. That means your body burns more calories even while you’re not performing physical activity.
What’s Better Machines or Free Weights?
Weight training—specifically with free weights, not exercise machines— will help you build lean muscle more than any other training method available. In order to build muscle, there must be enough of a stimulus on each muscle fiber to result in break-down or tearing of the fibers, followed by a subsequent rest or growth period.
This phenomenon occurs to a greater extent with weight training than with any other training method. This doesn’t mean other training methods aren’t beneficial, but it’s a fact that lean muscle tissue is developed to a much greater degree through resistance training with weights.
One of the important goals in combating the aging process is to preserve muscle tissue and prevent muscle atrophy, or the wasting of tissue. Sarcopenia is the loss of skeletal muscle tissue due to the aging process, during which muscle tissue is replaced by fat—whereby the metabolic rate severely declines. Since the aging process brings loss of muscle mass and a subsequent slowing of the metabolism, it makes sense to engage in the type of training that preserves the greatest amount of muscle mass.