With only very few exceptions, women can be trained with the exact same programming as men. Muscles respond to weight training with similar adaptations, regardless of sex. Women can benefit from a weight training program just as much, if not more than men. (Kraemer and Fleck 2007, Rippetoe and Kilgore 2006).
The benefits are dependent upon the implementation of fundamental training principles. The efficacy and specificity of the training protocol will dictate the training response. Toning and firming workouts have no basis in physiology and are ineffective. (Rippetoe and Kilgore 2006). Also see High Repetitions Burn More Fat Myth and Spot Reduction Myth.
There are, however, a number of differences between the performances of women and men. Generally, adult males are stronger than adult females. Interestingly, however, absolute strength relative to muscle mass are essentially the same between sexes.
Much of the difference in strength between men and women can be attributed to women's smaller stature, lower percentage of muscle mass, and significantly lower upper body muscle mass. Consequently, their upper and lower body strength averages 55% and 72% respectively of a man's strength. Women's world records for the bench press, squat, and deadlift were 60.4%, 65.7%, and 77.1% respectively of the men's world records.
A women's maximal power outputs (both absolute and relative to bodyweight) are less than that of men's. Women's maximum vertical jumps and long jump have been measured at 54-79% and 75% of men's, respectively. Also, women's world records for the clean & jerk and snatch were 73% and 72% respectively of the men's world records.
On average, women also have lower rate of force development, but slower fatigue rate in high-intense exercise. These differences may be largely attributed to slight differences in muscle fiber type composition, women's smaller type I and II muscle fibers sizes, and hormonal differences (ie: testosterone and estrogens).
Increases in muscle mass (both absolute and relative) are generally less in women, when performing the same program as men.
None of these differences warrant significant changes to the total design of a program.
Women, however, can use a higher percentage of their one repetition maximum (1RM) for greater number of repetitions, likely due to less efficiency in demonstrating true absolute strength through one repetition maximum performance. As a result, some modifications are required for women when their intensities are based on percentage of their one repetition maximum. Higher percentages of this one rep max generally need to be prescribed. For example, 70% of 1RM for 10 reps would constitute a heavy set for men, but this load would only be a medium load for women. Likewise, if muscle mass gains were desired, a higher training volume at a slightly higher intensity would be required. (Rippetoe and Kilgore 2006)
In conditioning for sports that are dependent upon upper body strength and power, slight emphasis should be placed on these sort of movements by adding one or two upper body exercises relevant to the specific muscle involved.
Active athletic women have fewer problems with premenstrual symptoms [eg: mood changes, appetite cravings, breast enlargement, mood changes] as compared to sedentary women (Prior, Vigna, and McKay 1992). Athletes also experience less frequent and less severe abdominal pain (dysmenorrhea) as compared to the general population (Dale, Gerlach, and Wilehite 1979).
Nevertheless, cooperation may be required between the coach and the female athlete during menses. Scheduling an offload week during this time may be appropriate to accommodate any potential issues of discomfort and associated effects (Rippetoe and Kilgore 2006).
Hormone concentration conditions appear to be more favorable for muscle growth in the follicular phase as compared to the luteal phase. Reis, Freik, and Schmidtbleicher (1995) reported greater isometric strength gains during an 8 week resistance training study when training frequency was greatest during the follicular phase (every other day) and reduced during the luteal phase (once a week) as compared to a program with no variation in training frequency (every third day). In contrast, Masterson (1999) found peak power, anaerobic capacity, and fatigue rate (via Wingate test) to lower during the follicular phase as compared to the luteal phase.
Since the testosterone peak 12 days prior to ovulation, a maximum workload scheduled at the end around this peak may possibly accelerate recovery and super-compensation. Although there is yet no study to validate, such timing would improve performance, this recommendation can be considered until future studies either verify or refute such a claim (Rippetoe and Kilgore 2006).
Most studies that have examined various measures of strength have not noted any significant menstrual phase effects (Frankovich and Lebrun 2000). It is also interesting to note that Olympic medal-winning performances have occurred during all phases of the menstrual cycle.
Not all studies support the rationale of the menstrual cycle-triggered training plan. For example, a higher acute growth hormone response to resistance training has been seen in the luteal phase compared to the follicular phase (Kreamer and Fleck 2004, Dziados 1993). There are also likely large individual variations of the effects of menstrual cycle phase on maximum strength and power, and athletic performance. Although varying training according to the menstrual cycle phase is an interesting hypothesis, more studies are required.
Research suggests that weight training is at least as beneficial for women, as it is for men, if not more so. Although there are notable performance and hormonal differences, as well as subtle fiber type variations between males and females, the adaptation processes and the training principles are essentially the same.
Fleck SJ, Kreamer WJ (2007). Optimizing Strength Training. Human Kinetics, 164-165.
Fleck SJ, Kreamer WJ (2004). Designing Resistance Training Programs. Human Kinetics, 3, 263-286.
Rippetoe M, Kilgore L (2006). Practical Programming for Strength Training. The Aasgaard Company, 243-245.