To better understand why hard-style kettlebells are so great for women, a little anatomy is in order. And let's get right to what matters -- The clitoris. Most people, women included, think that the clitoris is the little eraser-head sized nub of flesh atop the vulva. The "man in the rowboat." But in reality, that little nub isn't your whole clitoris. It's not even the tip of the iceberg. It's the snowflake on the tip of the iceberg. Technically that little nub that you're acquainted with is the "clitoral glans." The glans contains more nerve endings than any other structure in the human body (over 8,000), male or female, but the vast majority of the clitoris resides below the vulva, deep in the vagina and pelvic floor.
The clitoris branches off into two clitoral crura (also called "legs") which are made of a spongy material called corpora caverosum. This material traps blood during arousal and function as erectile tissue for the clitoris, exposing the glans above the clitoral hood. Just below the labia minora are the "vestibular bulbs" which trap blood during arousal to expand and expose the vulva. The enlargement of the crura and vestibular bulbs place more of the nerve endings of the clitoris into the path of stimulation, which in turn traps more blood in the erectile tissue. This blood is saturated with androgens, opiods, and other hormones which are now coursing throughout the bloodstream creating hypersensitivity and other secondary sexual responses. As arousal continues, muscles and ligaments in the vagina begin to contract. The glans retracts under the hood (but is still erect and engorged with blood) and the muscles of the pelvic floor begin to contract. At some point the threshold of stimulation is crossed and the muscles of the vagina, anus, uterus and pelvic floor begin cycling between full tension and relaxation at a sequence of 8-13 Hz. The hormone saturated blood trapped in the corpora caverosum and vestibular bulbs is released and orgasm is achieved as this cocktail of hormones hits the brain.
And what does a cannonball with a handle on it do to effect this epic series of biological events? The answer lies in the pelvic floor muscles (PFM). These muscles (the levator ani and the coccygeus) anchor the clitoris and provide it's structure. They are also the strongest muscles involved in orgasmic contraction. All the blood flow and resulting hormone circulation is provided by arteries and capillaries surrounded by these muscles. Many women might be familiar with the pubococcygeus muscle or "PC" muscle. This is part of the levator ani group and is the primary muscle effected by Kegel exercises, which will be discussed in later paragraphs.
The strength and consistency of female orgasm has been linked to the proper functioning of these important muscles. Traumatic events such as child birth, episiotomies and some hysterectomies can damage these muscles which can negatively impact women's ability to consistently reach orgasm. Without the structure to deliver well regulated blood flow into the crura and to provide cyclic contraction at the onset of orgasm, many women will have trouble climaxing, no matter how much direct stimulation occurs on the clitoral glans. So one would surmise that strengthening these muscles and increasing their ability to function properly would result in a positive change in sexual response. Enter the Kettlebell.
Hard-Style kettlebell exercise is primarily concerned with ballistic power delivery. This means cycling between states of maximum muscular tension and complete muscle relaxation in short time cycles. In short, the ability to develop maximum power in the shortest possible distance. This is how lifters lift, sprinters sprint, and boxers box. Kettlebell exercises provide a safe, quickly learned, and highly effective way for anyone with the requisite mobility to learn this type of tension-relaxation cycle. It also provides a way for people of all backgrounds to learn how to direct movement from their hips, which is how athletes move to deliver maximal speed and power. To better understand how these movements contribute to the strength of the PFM, let's look at the fundamental Hard-Style exercise -- the swing.
The swing is a movement that utilizes the inertia of the kettlebell to train the tension-relaxation cycle. The girevik (slang for kettlebell practitioner) propels the bell forward with the sudden forward movement of the hips which is generated by the contraction of the quadriceps and gluteal muscles. As the bell goes forward, it begins an arc because of the connection (but not flexion) of the arms. In this arc, the girevik quickly engages the latissimi dorsi, posterior deltoids, and rectus abdominus to create tension against the momentum of the moving bell and stop it's flight. At the top of the swing the girevik forcefully releases the breath held by the diaphragm, relaxes the abdominal, gluteal and quadricep muscles, and maximally engages the lats and hamstring muscles to propel the kettlebell back down it's arc towards the pelvis. And similar to hiking a football, the hips move back, the knees bend, and the interior spindles of the gluteals and quadriceps stretch, actuating the Stretch Shortening Cycle. At the bottom of the arc the now "loaded" gluteals and quadriceps fire, the hamstrings relax, and the girevik repeats the swing. This cycle takes about 1.5 seconds. That's 1.5 seconds between maximum tension and complete relaxation of all the major muscle groups in the legs, hips, and trunk. The swing is a powerful ballistic movement that places the body in a unique training state for most-non athletes. This training state is key to strengthening the PFM.
As the girevik trains with Hard-Style kettlebell exercises consistently with progressive overload, all the neuromuscular benefits common to resistance training occur. New neuromuscular junctions are generated and the firing sequence of muscle the muscle fibers becomes more efficient in the first few weeks, with hypertrophy in the weeks following that. The taxation of the cardiovascular system and phasphogen fuel system results in higher stroke volume and later onset of lactic threshold. The girevik becomes stronger and better conditioned. But because these motions, like the swing, are practicing total body tension and relaxation, the muscles recruited into the movement are located throughout the entire body. The girevik's somatic nervous system will recruit the requisite large muscle groups, but the autonomic nervous system nervous system with begin to recruit other, smaller muscles as their tension results in more efficient movement. Generating this type of power from the hips and constantly stabilizing the core places the muscles of the pelvic floor in sympathetic recruitment as this much total body force requires stabilization throughout the body against the sudden changes in velocity. The PFM constantly cycle between tension and relaxation throughout the workout and undergo the same consistent training and progressive overload as the major muscle groups recruited to generate the movement and share the same growth in motor units, recruitment efficiency, and hypertrophy. In short, the PFM get stronger.
The result is that in 8-12 weeks, female gireviks report many sexual benefits from Hard-Style training. Resistance training usually results in higher androgen production, so libido is increased in those cases. Stronger core muscles and more flexibility can lead to more athletic sex and better cardiovascular conditioning means sex is less tiring and can last longer. But more curiously, female gireviks report higher levels of sexual arousal, much stronger and more easily attained orgasm, even multiple orgasms for some women whom had not previously experienced them. This may have to do with stronger PFM contractions and better blood flow through the PFM and into and out of the clitoral erectile tissue before and after orgasm, respectfully. Slower flow out of the corpora caverosum and vestibular bulbs has been theorized to contribute to a less sudden refractory period in female sexual response, and stronger PFM could contribute to better control of this release of blood, keeping androgens and other sex hormones in the clitoris longer and allowing for further stimulation and continued orgasm.
Kettlebells are not a panacea and there are other exercises that can strengthen the PFM. Most famous are the Kegel exercises. Kegels train women (and men) to contract the pubococcygeus muscle for intervals of a few seconds in order to strengthen it. But Kegels have been shown to be difficult to train because women cannot see the muscle contract, as they would in a bicep curl. Because of this, a lot of women end up contracting the anal sphincter which, while providing some benefit to the levator ani, is not very effective. Kegels also have proven troublesome as a PFM strengthener because of the unusual nature of the exercise and women's inability to maintain a routine necessary for consistent training. Because they are not done "at the gym" many women simply forget to do them. Kettlebells represent an easily taught exercise with all the traditional benefits of resistance and cardiovascular training that fits into the usual way people "work out." The unique draw of kettlebells is that they provide a secondary benefit to the female sexual response on top of these traditional primary physical goals. In fact, gireviks need not even concentrate on these secondary benefits to achieve them. Many report them occurring "as if by magic." All they needed to do was swing the bell.