Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Hormones and Hypertrophy, Why does every session count? 1 Hypertrophy and Hormones – Why does every session count? Hypertrophy is important an individual who wants to lose body fat, change shape, health. This is because hypertrophy is an increase in the size of a muscle, it increases metabolic rate and has been correlated to immune function Hormones play a key role in driving hypertrophy adaptation and these hormones can be controlled through different programming styles (see below). Often these differences in program structure are designed to affect the release of particular hormones. Number of Intensity 1RM% Reps Sets exercises Six 70-80% 8-10 3-4 Rest Endocrine period response 2-3 min Increased reps testosterone, cortisol and catecholine release Six 70-80% 10-12 3-4 45 increase in sec1min Growth hormone, cortisol Six 80-95% 1-5 4-6 3- 4min Increased Cortisol and testosterone 2 Hypertrophy is the result of changes to the muscle architecture e.g. pennation angle and/ or the size of individual muscle fibers (ref). This leads to an increase in the size of the muscle. The structural changes and Pennation angle is the line of pull of a muscle fiber towards the tendon. the increase in size of the muscle (tissue remodeling) occur over a period of weeks or months. However the tissue re-modeling process is initiated by the secretion of hormones into the blood by the glands of the endocrine system after just one session. In addition, the acute endocrine response to a hypertrophy session can be used to improve performance in competitive play. An increase in testosterone has been shown to improve coordination, the force of muscular contractions and reaction time (Kramer and Ratamese 2005, Turener et., al. 2010) In addition, the acute endocrine response to a hypertrophy session can be used to improve performance in competitive play on the same day (Turner et., al. 2010). 3 Fig 1. Illustrates the name and location of the major Endocrine glands. The endocrine system is a network of glands responsible for regulating a water balance, blood pressure and a number of biological processes (ref). During a A Metabolite is a byproduct of muscular contractions e.g. blood lactate and Hydrogen ions. hypertrophy session (H.S.) the endocrine system is stimulated by the increase in metabolites and damage to muscle fibers. The immediate hormonal response of the Endocrine system to a bout of hypertrophy training is called the acute response (Kraemer and Ratamese 2005, Turner et., al 2010). During the acute response catabolic hormones are released into the blood by endocrine glands. The catabolic phase is followed by the release of anabolic hormones. This process of catabolism and anabolism allows the tissue remodeling to take place (response (Kraemer and Ratamese 2005, Turner et., Catabolic hormones break down muscle tissue Anabolihhormoes al 2010). The hormones that are released during the acute response can be classified as breakers, builders and boosters. Breaker Cortisol (Glucocorticoid steroid) Causes inflammation and releases energy from muscle tissue Anabolic hormones stimulate growth and repair muscle Builders Booster Testosterone (Steroid hormone) IGF (Peptide hormone) Catecholines epinephrine and norepinephrine,, increase heart rate and blood pressure Reduce inflammation and aids tissue repair and increase the size of a muscle. 4 testosterone- increases coordination and The force of muscle contractions Fig 2. Illustrates the different types of Endocrine hormones during the acute phase. In order to design the appropriate workout for an athlete; the coach must understand the hormones released during the acute response and the factors that can have a positive or negative effect. It is believed that the cortisol to testosterone ratio should be at an appropriate level during the acute phase (Tuner et, al., 2010). If cortisol is too high for a long period of time this may break down muscle tissue excessively and have a negative effect on muscle growth (Tuner et. al., 2010). However it has also been shown that high cortisol levels immediately after a H.S. lead to elevated testosterone levels (Durand et, al 2003). Which suggests the ratio of C:T during the acute phase is not a critical factor (Kramer and Ratamese 2005). As the research is unclear in this area it would be prudent for the strength and conditioning coach to avoid training athletes for excessive periods of time e.g. 2-3 hours unless it is needed for the sport. Table 1. – Lists the factors that can affect the acute endocrine response to hypertrophy session. Factor Recommendation The type of Exercises that use large muscle groups will create a larger 5 exercise testosterone response and greater metabolic cost Percentage of 75-85% of 1Rm is needed to trigger an acute response 1RM Exercise order Avoiding alternating muscle groups e.g. doing upper then lower body exercises will promote pooling of metabolites in the working muscles and increase IGF levels in the blood Training history Experienced resistance trained athletes will have a larger acute response than endurance or untrained athletes Age Younger athletes e.g. 20-30 years old will have a larger acute response than older athletes. Gender Men will have a greater Testosterone response than women. Women rely on IGF mechanism for muscle growth. Genetics Some individuals will have a greater response than others. Sets Higher number of sets e.g. 2.4 will create have a larger acute response than 1-2 sets (ref). Rest period Rest periods of 2 minutes are better for testosterone release. There are many factors that can influence an athlete’s acute response to a hypertrophy session e.g. exercise selection, order, age and gender. Most of the current research is in agreement of how the aforementioned factors can affect acute response. However there is some disagreement in the appropriate number of sets and the length of rest periods. This is due to the procedures used during the research design and subject groups used. An acute response to a H.S. has been shown with 6-10 repetitions 6 Similarly a previous study on H. S. done in circuit form has shown to produce acute endocrine response . However this could be due to the subjects being untrained. A study in 1992 involving you and old men doing ten repetitions of squats with 80%1RM raised C, T and IGF in resistance trained men. Research into the acute response of a H.S. has showed that multiple sets e.g.4-6 performed by an experienced athlete lead to a greater response (Durand et. al, 2003, Hameed et. al., 2003). Listed below is an example of a resistance session for a young male flanker with three years previous experience who needs to improve shoulder mid and upper back strength. Exercise Reps Sets Rest period A1 Hang clean 6-8 4 B1 Chin up 8-10 4 B2 Standing 8-10 4 8-10 4 2 min 2min barbell press. C1 Partially supinated shoulder press dumbbells C2 Bent over row 7 C3 Single arm 810 4 90sec row The individual who wants to use hypertrophy training to improve body composition (reduce body fat), improve muscle tone and overall health. Must consider their current fitness level, training experience, gender and age before choosing a program. The exercises chosen during the session must be functional for the individual and create the correct hormonal environment for fat loss and muscle growth. References and Acknowledgements 8 Durand, J.R., Castracane, V.D., Hollander, B.D., Trynieck L. J., Bamman, A.M., O’Neal, S., Heibert, E.P., Kraemer, R., (2003), Hormonal response to Eccentric and Concentric Muscle Contractions, Medicine and Science in Sport and Exercise, 35(6), 937-943. Hameed, M., Orwewll, W.R., M. Connold, Goldspink, G., Harridge S.D.R., (2003), Expression of IGF-splice variants in young and old human skeletal muscle after a high resistance exercise bout, The Journal of Physiology, 547, 247-254. Holm, L., Reitelsder, S., Pederson, Doessing, S., Peterson, S.g., Flyvjerg, A., Anderson, J.L., Aagard, P., Kjaer., 2008, Changes in Muscle Size and MHC Composition in Response to Resistance with Heavy and Light Intensity, Journal of Applied Physiology, 105(5), 1455-1461. Kraemer, J. W., Hakkinen, J., Newton, U. N., Nindl, B., Volek, S., Mc Cormick, M., Gotshalk, A. L., Gordon, E.S., Fleck, J.S., Cambell, E.W., Putikian. M., Evans, J.W., (1999) Effects of heavy-resistance training on hormonal response patterns in younger versus older men, The Journal of Applied Physiology, 87, (3), 982-992. Kraemer, J.W., Ratamess, A.N., (2005), Hormonal Response and Adaptations to Resistance Training, Journal of Sports Medicine, 35, (6), 937-943,2003. References and Acknowledgements 9 Kreiger,W.J., (2010), Single vs. Multiple Sets of Resistance Training for Muscle Hypertrophy a Meta- Analysis, Journal of Strength and Conditioning Research, 24, (4), 1150-1159. Mcguigan, R.M., Egan, S, A, Foster, C., (2004), Salivary cortisol responses and perceived exertion during high intensity and low intensity bouts to resistance exercise, Journal of Sports Medicine, 3, 15-18. Pyka, G., Wisewell, R. A., Marcus, R., (1992), Age Dependent Effect of Resistance Exercise on Growth Hormone Secretion in People, Journal of Endocrinology, 75, (2), 404-407. Shulmberger, A., Stec, J., Scmidtbleicher, D., (2001), Single Set Versus Multiple Set Strength Training in Women, Journal of Strength and Conditioning Research 15, (5), 284-289. Turner, A., Comfort, P., Moody, J., Jeffreys, (2010), Neuroendocrinology and Resistance Training in Adult Males, U.K. Strength and Conditioning Association, Spring, (17). 10