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Health Benefits of Weight Training Increases bone density (Hurley 1994) Increases glucose uptake (Hurley 1994) Increases gastrointestinal transit time (Koffler 1992) Improved HDL levels (Stone 1982, Hurley 1988) Reduced resting blood pressure (Harris 1987) effects of weight training equal to aerobic exercise (Westcott 1995) Reduced low back pain (Risch 1993) requires isolated low back strength training Reduced osteoarthritis and rheumatoid arthritic pain (Tufis 1994) Reduced depression (Signh 1997) Life Strength Men and women reach peak strength around 20 to 25 years of age. After age 25, strength generally decreases an average of 1% per year. Therefore, a 65 year old would only have about 60% of the strength they had at age 25. Individuals who are more active, or those who continue to strength train, can considerably decrease this tendency for declining muscular strength. Strength training for older adults can reverse the loss of muscle mass and enhance their ability to perform activities of daily living. Welle S. Resistance training in older persons. Clinical Geriatrics 1998;6 (1):48-59. Radakovich J. Prescribing resistance training for elderly patients. Your Patient and Fitness 1997;11(2):27-30. Strength Correlates to Muscle Size A muscle's strength has a strong relationship to its cross sectional area in both men and women. Muscle enlargement with a corresponding increase in strength was first shown scientifically as early as 1897. Ikai M, Fukunaga T, Calculation of muscle strength per unit cross-sectional area of human muscle by means of ultrasonic measurements. Int Z Angew Phsiol, 26:26-32, 1968. Hetting T: Physiology of Strength. Springfield. Ill, C. C Thomas, 1961. Morpurgo B: U:ber Aktivita:ts-Hypertrophie der willkurlichen Muskeln. Virchows Arch. Pathol Anat Physiol, 150:522-544, 1897. Strength Recovery Strength recovery was noted in an early exercise physiology textbook. Elbow flexors were tested for strength and were worked to exhaustion. 69% of strength was regained after 30 seconds of recovery 82% of strength was regained after 2.5 minutes 87% of strength was regained after 7.5 minutes 95% of strength was regained after 42.5 minutes only 26% more than what had been regained after a 30 second rest Morehouse LE, Augustus TM (1971), Physiology of exercise, The C.V. Mosby Company, Saint Lois, 6th Ed, pg 60. Fiber Types Heavy resistance training can stimulate hypertrophy of both Type I and II fibers, with Type II fiber experiencing the greatest rate of hypertrophy. Also see Fiber Type Comparison. Gonyea & Sale 1882; Hakkinen & Komi 1985; Hakkinen, et al 1989; MacDougall et al. 1980; Thorstensson 1976. Combined Muscular Strength It is estimated that if all the muscles of the human body work together, that it could lift 11 tons, the equivalent of 4 SUVs.

Neuromuscular Efficiency Strength training increases neuromuscular efficiency Increased number of motor units recruited Increased firing rate of each motor unit Increased synchronization of motor unit firing Also see Motor Development. Muscular Endurance Resistance training incorporating high-volume, moderate-intensity, and short rest periods, may increase capillarization in the muscles (Schantz 1982; Tesch, et al. 1984). Bodybuilders who typically perform this sort of training were able to exercise at a higher percentage of their 1 rep max for 3 sets of 10 repetitions, compared to powerlifters when plasma lactate concentrations were equally elevated in both groups (Kreamer et al 1987). Interdependent Strength Strength gains from a particular exercise or movement appear to effect strength gains of other exercises for similar or even adjacent movements. Examples: Introduction of Weighted Chest Dips may increase strength in Bench Press, Incline Bench Press, and Shoulder Press. Introduction of Pullover may increase Chin-up strength. The increased strength for Chin-ups may also, in turn, increase strength for more remotely related exercises such as Chest Dips, Bench Press, or Arm Curls. Although the moments are not exactly the same, common muscles are involved with these different movements. This phenomenon would suggest that a particular new exercise added to a workout may indirectly increase strength for other more commonly performed exercises, even seemingly unrelated movements. Also see Interdependent Strength following injuries. Osteoporosis Approximately 20 million women in the United States are affected by osteoporosis, leading to multiple fractures and increased hospitalizations. Boning up on osteoporosis: a guide to prevention and treatment. Washington, D.C.: National Osteoporosis Foundation, 1991. Resistance training has been shown repeatedly to increase bone marrow density, which can decrease the morbidity and mortality resulting from osteoporosis. Hamdy R., Anderson J, Whalen K, Harvill L. Regional differences in bone density of young men involved in different exercises. Medicine and Science in Sports and Exercise 1994; 26: 884-888. Heinonen A, Oja P, Kannus P, Sievanen H, Manttari A, Vuori I. Bone mineral density of female athletes in different sports. Bone and Mineral 1993;23:1-14. Karlson M., Johnell O. Obrant K. Bone mineral density in weightlifters. Calcified Tissue International. 1993;52:212-215. Nelson ME, Fiatarone MA, Morganti CM, Trice I, Greenberg RA, Evans WJ. Effects of high intensity strength training on multiple risk factors for osteoporotic fractures. A randomized controlled trial. JAMA 1994;272(24):1909-1914. Pocock NA, Eisman J, Gwinn T, Sambrook P, Kelly P, Freund J, et al. Muscle strength, physical fitness, and weight but not age to predict femoral neck bone mass. Journal of Bone and Mineral Research 1989;4(3):441-448. Menkes A, Mazel S, Redmond RA, Koffler K, Libanati CR, Gundberg CM, et al. Strength training increases regional bone mineral density and bone remodeling in middle-aged and older men. Journal of Applied Physiology 1993; 74(5):2478-2484. Early Kinesiology Study FE Nipher, Assistant Professor of Physics in Washington University (1875). On the Mechanical work done by a muscle before exhaustion. American Journal of Science and Arts. 9(100), 130-137. This article was published in America's first scientific journal. The journal article mentions strength adaptation, daily work volume (kgr.-meters), dynamometer, and differentiates 'static work' versus 'dynamic work'. Nipher also later published a study on a form of serial positioning effect. Dumbbell Origin "The original dumbbell was an apparatus contrived like that for ringing church-bells; that is, a heavy fly-wheel with a weight attached, which was set in motion like a church-bell, until it acquired sufficient impetus to carry the gymnast up and down, and so bring the muscles into active play. There is one at New College, Oxford, to the present day. The modern weights, so called, produce similar results, in a less cumbrous and more agreeable manner." - Edwards' Words, Facts, and Phrases. Phyfe WHP (1901) Five Thousand Facts and Fancies, GP Putnam's Sons, pg 250.