Plyometrics is a type of exercise training designed to produce fast, powerful movements, and improve the functions of the nervous system, generally for the purpose of improving performance in sports. Plyometric movements, in which a muscle is loaded and then contracted in rapid sequence, use the strength, elasticity and innervation of muscle and surrounding tissues to jump higher, run faster, throw farther, or hit harder, depending on the desired training goal. Plyometrics is used to increase the speed or force of muscular contractions, often with the goal of increasing the height of a jump.
Plyometric training involves practicing plyometric movements to toughen tissues and train nerve cells to stimulate a specific pattern of muscle contraction so the muscle generates as strong a contraction as possible in the shortest amount of time. A plyometric contraction involves first a rapid muscle lengthening movement, followed by a short resting phase, then an explosive muscle shortening movement, which enables muscles to work together in doing the particular motion. Plyometric training engages the myostatic-reflex, which is the automatic contraction of muscles when their stretch nerve receptors are stimulated.
Plyometric exercises use explosive movements to develop muscular power. Plyometric training acts on the nerves, muscles, and tendons to increase an athlete’s power output without necessarily increasing their maximum strength.
Though males and females have the same musculoskeletal structures, there are some unique differences that actually make female athletes more prone to injury. In regard to skeletal differences, males usually have wide shoulders and narrow hips, whereas a female generally has a wide pelvis in relation to the width of her shoulders. The females wider pelvis is necessary for childbirth. This wider pelvis in females leads to an increased inward slant of the thigh and, therefore, an increased Q-angle of the knee. An increased Q-angle produces excessive lateral forces on the quadricep’s mechanism and abnormal tracking of the patella. This is one of the reasons why chondromalacia patella or patellofemoral syndrome is more common in women. As stated above, a female’s thighs tend to slant inward towards the knees more than a male’s. This puts additional strain on a woman’s hips and their ligamentous support.
The average body fat content of the female is approximately 26 per-cent, compared with that of the male at 14 percent. The female has a lower lean body mass indicating less muscle mass. The greater muscle mass in males is due to the predominant effect of the androgen hormones, whereas estrogen, predominant in females, results in increased body fat. As it turns out, this difference in hormones is key to understanding why female athletes are more easily injured and repair more slowly than their male counterparts. Testosterone stimulates fibroblastic proliferation, whereas estrogen, especially estradiol, inhibits it. It is for this primary reason that female athletes can benefit from Prolotherapy for their sports injuries. Estrogen makes a woman a woman, but they have a definite negative effect when it comes to healing sports injuries.
Females also have a smaller proportion of muscle in relation to body size because of the hormonal differences. Having less muscle tissue means there is less muscle to stabilize the joints if the ligaments are injured. This causes more stress to be placed on injured ligaments in women.
Females have a low metabolic rate, the rate of conversion of food to energy under conditions of total rest. This could be one explanation why females heal sports injuries slower than men. Females performing strength training gain increased strength with relatively less muscle hypertrophy. Because females have significantly less testosterone, when a woman does weight strength training, she will get stronger, but she cannot turn herself into a body shaped like a man because the hormones are just not there. Recent epidemiological studies have recognized a significantly higher anterior cruciate ligament (ACL) injury rate in female athletes as compared with male athletes in sports such as basketball, hand-ball, gymnastics, and soccer. Although various causes of this phenomenon have been postulated, including differences in ligament or muscle strength, conditioning, endurance, anatomy, and training techniques, the most plausible appears to be the hormone factor.
Unique to the female athlete is her exposure to a constantly changing hormonal milieu throughout her reproductive years. For most of her life, the female athlete is exposed to rhythmic variation in either endogenous hormones during a regular menstrual cycle or exogenous hormones via oral contraceptives. It has been only recently that it was discovered that there are estrogen receptors on the fibro-blasts of the human ACL, suggesting that female sex hormones may have an effect on the structure and composition of this ligament. Dr. Stephen Liu and associates, at the UCLA School of Medicine, made this discovery and went the next step to find out exactly how estrogen affects ligament growth. They investigated the effects of 17B-estradiol on the cellular proliferation and collagen synthesis of fibroblasts derived from the rabbit anterior cruciate ligament. Measuring 3H-thymidine and 14C-hydroxyproline incorporation assessed fibroblast proliferation and collagen synthesis, respectively. They found that collagen synthesis was significantly reduced with increasing local estradiol concentration. Declining collagen synthesis was first noted at a 17B-estradiol concentration of 0.025 ng/ml. Within physiologic levels of estrogen (0.025 to 0.25 ng/ml), collagen synthesis was reduced by more than 40 percent of control, and at pharmacological levels of 2.5 and 25 ng/ml, as typically occurs in female atheletes taking birth control pills or estrogen replacement therapy, by more than 50 percent of control. A significant reduction of fibroblast proliferation was also observed with increasing estradiol concentrations. These results are startling.
Estrogen, the female hormone, dramatically inhibits fibroblasts. These fibroblasts are what make the collagen that makes up the ligaments and tendons, which are injured during sports. Estrogen was shown in the above study to inhibit the fibroblastic growth and thus collagen formation in a dose-dependent manner. The more estrogen a woman has, the more inhibition will occur. This has direct effects for all women taking birth control pills. Birth control pills have pharmacological levels of estrogen, which are far in excess of a woman’s normal production. The simplest way for a female athlete, who is on artificial estrogen, to overcome sports injuries, is to stop taking them. Inevitably, women are placed on birth control pills because of menstrual irregularities, which are easily treated with natural medicine techniques including diet manipulation and nutritional supplements.
The female athlete inevitably comes up essential fatty acids deficient. This means they need to injest more good fats in their diets in the form of omega-3 fatty acids as is found in fish oils. They are encouraged to drink cod liver oil and eat more fish. Better kinds of fats are also found in nuts and seeds, flaxseed oil, and olive oil. Just this mild change in diet is typically all that is needed to get rid of menstrual cramps and other menstrual irregularities. Sometimes, however, more sophisticated dietary manipulation, herbal supplementation, or other natural medicine techniques may be needed.
This weekend the U12 and U9 Wildcats went to their first tournament; the Placer United Invitational. The tournament was originally billed as a Division 3 tournament, but I just looked at the website and it says “Div. 1 and 3 teams are welcome to apply.” I assure you it was advertised as a Div. 3 tournament when I signed the team up. Boy did the Div. 1 teams show up, because we were definitely not in their league yet. Our best and first game was a 5-1 loss to a Clovis-Fresno team.
Our second loss came at the hands of Elk Grove – Everton FC at 2:40 in the afternoon with a mild temp of 110 degrees. The Elk Grove team had 4-5 players that were 5’10″ and not one was below 5’2″. My only thought here is that they are going to be a U13 team at the age cutoff date of July 31. Either that or the player passes are ornamental and just a formality to create the illusion of propriety. I was walking by a girl and she said to her parents, “They are only 10 and 11 year olds.” Which is an odd comment coming from an alleged 11 year old. The coach of the team restrained his team, but it didn’t stop his goalie, all 5’10″ of her, from dribbling from her goal, through our team and scoring. At this point the score was at least 10-0, so the drive through our exhausted and overheated players was probably unnecessary.
Although game 2 was a drubbing, our girls gave them a heck of a battle for a good 10 minutes. Stopping shot after shot and running as hard as their legs, lungs and hearts allowed. Because of the heat, the game had been broken-up in to quarters. We talked at the last quarter and the girls went out and gave their all – there is nothing more we could have asked from our warriors.
Game 3 came at 8am on Sunday morning. Our girls learned a lot the day before and our defense was much better organized. We still were soundly defeated by Deanza Force, but the players had more respect for their coach and us when it was obvious they had the game well in hand.
Each of our players left a part of themselves on the field this weekend. Whether it was Beena, who was in so much pain when she ran that I could feel it, to the burning lungs of Zabrina and Amara as they pressured the ball in the hellish heat. Kayla, our 9 year old wonder, was a force and didn’t back down when challenged by the much older girls. Our goalies, unfortunately, couldn’t have gotten more practice and boy did they show-up. From Riley’s 1v1 dash at an Everton monster to make her miss the shot to Katherine’s “Kat” like reflexes to block shot after shot, we were impressed.
Although it was a tough weekend, both physically and emotionally, we need to use this as a wake up call to the talent that is out there and that we have a lot of work to do. The girls definitely have the heart, now we just need to work on the game.
