Chapter 6: Training for Strength 134 Physiological Differences Between Males and Females There are numerous physiological differences between males and females which can result in significant disparities in their response to strength training. For example, females have fewer and smaller muscle fibers than males. Even so, females have the same array of muscle fiber types as males, both type I, type II and all of their sub-types (Zatsiorsky & Kraemer, 2006). Seventy five percent of untrained females have slow-twitch fibers that are larger than the fast-twitch fibers. The average female’s maximal mean total body strength is about 60% of the average male’s maximal total body strength. Average upper body strength of females ranges from 25-55 % of male’s average upper body strength. Average lower body strength of females ranges from 70-75% of male’s average lower body strength (Fleck & Kraemer, 2004). Finally, resting circulatory concentrations of testosterone are 10-20 times lower in females than in males (Kraemer & Ratamess, 2003). According to Zatsiorsky & Kraemer (2006), females, especially basketball players, have higher incidences of anterior cruciate ligament (ACL) injury due to a narrower trochanteric notch and other anatomical factors such as broader hips and a greater Q-angle of the knee. With this in mind, females, especially athletes, can help to reduce the risk of injury and improve performance through regular strength training and proper technique. Load and Repetition Assignments Based on Training Goal Like endurance training, there are several different types of strength training programs: endurance size, strength and power. Each type of strength training has its own specific guidelines in terms of load, goal reps, goal sets and rest intervals. Table 6.3 depicts the training guidelines for the four different types of strength training (Haff & Triplett, 2016). Table 6.3. Load and Volume Assignments based on Training Goal Training Goal Load (% 1RM) Goals Reps Goal Sets Rest Endurance ≤ 67 ≥ 12 2-3 ≤ 30 sec. Hypertrophy 67-85 6-12 3-6 30-90 sec. Strength ≥ 85 ≤ 6 2-6 2-5 min. Power 75-90 1-5 3-5 2-5 min.