1. You Don’t Have to Be Big to Be Strong
Strength training involves training the muscles and the nervous system--together they make what is called the neuromuscular system. Having big muscles doesn’t guarantee that you will be stronger than someone with smaller muscles who trains for strength. It depends on how you train--and natural ability, of course.
For example, in 2003 at the age of 40, Raija Koskinen of Finland set a world record for the women’s squat in the 97-pound (44 kilogram) bodyweight class. She squatted 377 pounds (171 kilos).
Bodybuilders emphasize more repetitions with lighter weights while strength athletes lift heavier weights for fewer repetitions.
2. Free Weights Activate More Muscles than Machine Weights
Free weights generally require muscles other than those in the target muscle group to stabilize the weight when you move it. With machines, the weight path is restricted and controlled by the machinery structure and fewer ancillary muscles are required during the lift, pull, or push.
Even so, machine weights do an excellent job of challenging muscles. You can get variety and results if you do both free weights and machine weights.
3. Steroid Abuse Can Shrink the Testes, Promote Male Breasts, and Enlarge the Clitoris
Anabolic steroids are used to enhance muscle tissue growth and provide the ability to train harder and recover quickly from exercise-related stress. They are still widely used in non-competitive activities for the enhancement of body size and strength. Most competitive sports have made anabolic steroid use illegal.
Because anabolic steroids act like the male hormone testosterone, the body tends to decrease its natural production of this and other important sex hormones when supplied with external steroids. Side effects of the hormonal disruption may include atrophy of the testes and male breast enlargement (gynecomastia). In women, enlargement of the clitoris, a reduction in breast size, excess body hair and disrupted menstrual cycle can occur.
4. Eccentric Exercise Makes You Sore
When you bend your arm to lift a dumbbell, the action you take is concentric. This occurs when the joint angle decreases and the target muscle, the biceps, shortens. When you return the dumbbell to the starting position, you straighten the joint and lengthen the muscle in what is called "eccentric" movement.
As a general rule, eccentric exercise causes more muscle damage and soreness than concentric movement. Some weight trainers emphasize eccentric exercises because they believe it builds muscle faster. Either way, go easy on the eccentric exercise.
5. It’s Difficult to Increase Muscle While Losing Fat
I won’t say it’s impossible, but it is unlikely that you can lose body fat and increase muscle at the same time. The body does not deal well with contradictory metabolic phases--in this case losing and gaining at the same time. The best you can probably hope for is to maintain muscle while losing fat.
Experienced bodybuilders do it in two phases. First, they build up body bulk, including some fat, by overeating and weight training. In the second phase they trim the fat and maintain the muscle with a carefully constructed diet while continuing their muscle development program.
In a weight loss program, your best option is to ensure you continue to weight train during fat loss and after your weight stabilizes in order to maintain muscle at an optimum level.
6. Weight and Aerobic Training Affect the Heart in Different Ways
You may have heard the expression "enlarged heart" referring to an adverse health condition in which the heart muscle, including the chambers of the heart, are enlarged. This abnormal heart enlargement occurs because the heart muscle is weakened by an underlying disease process (heart disease); the heart dilates to partially compensate for the weakened pumping action of the heart as a result of disease.In contrast, athletes tend to have enlarged hearts because of the amount of stress they place on the heart's pumping requirements to fuel their training and competing. So some degree of heart enlargement in athletes is usually a normal response to exercise. It is not unhealthy, and may even be beneficial. Endurance athletes, like marathoners, tend to have larger chamber sizes while strength athletes, like powerlifters, tend to have thicker muscle walls.
The best outcome may well be a combination of both types of exercise: weights and aerobics.