The skeletal muscles of men and women are very similar in structure and function. Men have a higher concentration of testosterone produced in their body. Ultimately, this increased availability of testosterone predisposes a man to developing more muscle mass. The differences in gender become apparent in exercise performance simply because men have more muscle mass available to produce energy. This energy is expressed as greater endurance, speed, strength and power. Men also have different genital muscles necessary for reproduction.
Reproductive Muscles
The male genitalia muscles are located in the scrotum. The wall of the vas deferens has a thick muscular layer of circular and longitudinal muscle fibers. This muscle helps to propel the sperm into the urethra in the penis during ejaculation. The dartos muscle is located just under the skin of the scrotum. It slightly elevates the testes and wrinkles the scrotum. The cremaster muscle significantly elevates the testes closer to the body. It is part of the spermatic chord, a protected tube housing the vas deferens, nerves, blood vessels and lymph vessels.
Upper Body Muscles
Men generally have much larger upper body muscles compared to women. Men have more absolute strength compared to women. However, according to William McArdle and collegues, in their book "Exercise Physiology, Energy, Nutrition & Human Performance," when muscle mass and training status is equal for the bench press exercise, men were only 2.5 percent stronger. The pectoralis major and minor are the primary muscles engaged in the bench press. They fan from the breast bone and ribs to insert on the arm and shoulder blade. The large, V-shaped muscle spreading across the lower to middle of a body builder is the latissimus dorsi. This muscle originates on the vertebrae and hip bones and then inserts on the arm. The thick muscle you see at the base of a weight-lifter's neck is the trapezius muscle. It spans from the base of the skull and the spinal bones, inserting on the clavicle and shoulder blades. The arm muscles include the deltoids, biceps, triceps, brachialis and brachioradialis.
Lower Body Muscles
When high-intensity cycling was adjusted for gender differences, William McArdle reports men still had an average of 20 percent greater anaerobic capacity. Men are able to more quickly exert force without the use of oxygen compared to women. The major hip extension muscles are the gluteus and hamstrings muscle. The psoas and iliacus muscles bend the hip joint, drawing the thigh toward the chest. The quadriceps, made up of four different muscles, lies at the front of your thighs. The adductor muscles bring the thigh toward the middle of the body. The tibialis is the muscle you feel in your shins. When you flex your calf, the horseshoe shaped muscle is your gastrocnemius; the lower calf muscle is your sartorius.
References
- "Anatomy & Physiology"; Gary Thibodeau, Ph.D. and Kevin Patton, Ph.D.; 2007
- "Exercise Physiology, Energy, Nutrition & Human Performance"; William McArdle, Frank Katch and Victor Katch; 2007
