Elder population! Hypertrophy equates to bigger muscles, therefore if a larger muscle mass is exercised then the strength gains will be better than if being in a normal or atrophic state. Having written this when performing isometric exercises which give some strength gains are better performed in terms of holding the position for longer, when the muscle mass is smaller, due to blood volume within the muscle. The answer to your question would be better defined if we were told what your objective is.

Hello, I am writing a response for you with the bibliographic references cited with the numerical system (to save space). My English is not very good, so I will use the translator to write to you.

According to scientific evidence, the optimal working weight against resistance to increase muscle mass in the elderly is 60% to 80% of 1RM (2 to 4 sets per exercise or muscle group, 2 to 3 days a week), This intensity is what allows you to perform between 8 and 15 repetitions and is what causes the most significant anabolic effects, while working with a lower load does not cause muscle hypertrophy; Logically, we will begin with an adaptation program (1,2). On the other hand, maximum strength training (with maximum weight) is the most effective for increasing maximum strength in older adults, but not the most effective for increasing the functionality of older adults (44). With power strength training, the most significant improvements in functional variables (speed of climbing stairs, getting up from the chair, and walking speed) are achieved (44). Resistance strength training (low weight), hypertrophy strength training (moderate weight) and maximum strength training (high weight) cause similar improvements in functional variables (45,46,47), but the most significant improvements in functionality, they are achieved with power training (44).

It is known that muscle hypertrophy occurs in response to the release of growth hormone (3-11) and in response to the release of testosterone (7,12-24), but their production of both hormones is reduced during aging. That is, the older we are, the less amount of growth hormone we produce (27-32) and the less amount of testosterone as well (25,26), even so, in the elderly, exercise can cause an increase in these hormones.

The type of exercise that most increases the concentration of growth hormone in the blood is lactic anaerobic exercise, that is, exercises that involve high intensity and repetitions or medium-long duration with short pauses (30,33-35), such as high intensity interval exercise (HIIT) (36,37).

Transferring this evidence to the practical field, it has been verified with exercise against resistance (muscle training - weights); that high-intensity and short-duration training (such as maximum strength) does not cause the release of a large amount of somatotropin, but training with a slightly lower intensity, but a greater number of repetitions and less time of pause (hypertrophy strength), are those that favor the release of GH (38), as long as the volume of work (number of repetitions and series) is significant, since, if the number of repetitions is very low, no increase is evident. significant although the intensity is not so high (39). In turn, it has been proven that isometric exercises are the ones that release the least amount of GH (40), so it could be considered that this type of exercise is the least useful, if the objective of the training is development. muscular.

Regarding the type of training to release testosterone, resistance exercise (strength training) seems to be the most effective as well; It has been shown that high volume of work, short breaks, high intensity, prolonged session and evening training are variables that positively affect the release of testosterone (12), although of all these variables, it seems that high volume work and short breaks are the variables that most positively affect the release of testosterone; since, it has been shown that hypertrophy strength training (60-80% of 1RM) causes more significant increases in blood testosterone than maximum strength training (80-100% of 1RM); and that resistance strength training (30-60% of 1RM) causes more significant increases in blood testosterone than hypertrophy strength training (38,41), although others find greater release of testosterone with hypertrophy strength training than with that of maximum strength or resistance strength (42).

Although the amount of testosterone and somatotropin released in response to strength training is more significant in young people than in older adults, an increase in these hormones in response to exercise is also evident in older adults (43).

In summary: Considering that lactic anaerobic exercise, such as hypertrophy strength exercise (60-80% of 1RM with 8 to 15 repetitions in the gym), is what causes significant increases in both somatotropin and testosterone in the blood, it could be considered the most appropriate type of exercise to increase muscle mass or at least prevent its loss. While, if the aim is to improve the functionality of the elderly, the ideal is to work on power strength.

REFERENCES

1. Ávila-Funes, J. A., & García-Mayo, E. J. (2004). Beneficios de la práctica del ejercicio en los ancianos. Gaceta médica de México, 140(4), 431-436.

2. Palop Montoro, M., Párraga Montilla, J. A., Lozano Aguilera, E., & Arteaga Checa, M. (2015). Intervención en la sarcopenia con entrenamiento de resistencia progresiva y suplementos nutricionales proteicos. Nutrición Hospitalaria, 31(4), 1481-1490.

3. Scarfó, R. L. (2005). Los factores de crecimiento muscular y los ejercicios de fuerza. Lecturas: Educación física y deportes, (83), 29

4. Fernández-Tresguerres Hernández, J. A., Ariznavarreta, C., Cachofeiro, V., Cardinali, D. P., Escrich, E., Gil Loyzaga, P., ... & Tamargo Menéndez, P. (2005). Fisiología humana. McGraw-Hill

5. Saladin, K. S. (2013). Anatomía y fisiología: la unidad entre forma y función (6a. McGraw Hill México.

6. Ocaña, A (2014). Hidratos de carbono, hormonas y rendimiento en las pruebas de resistencia.

7. Rosa, A. (2015). Fisiologia en el entrenamiento de la aptitud física muscular. Efdeportes. com, 1.

8. Haff, G. G., & Triplett, N. T. (Eds.). (2015). Essentials of strength training and conditioning 4th edition. Human kinetics

9. Arhancet Radesca, M. L., Delgado Blanco, S. N., & Díaz Gómez, V. (2016). Determinación de las variaciones séricas de glucosa pre y post competencia en el equino de resistencia (RAID)

10. Aguilar Macías, A. S., Miranda, M. D. L. Á., & Quintana Díaz, A. (2017). La mujer, el ciclo menstrual y la actividad física. Revista Archivo Médico de Camagüey, 21(2), 294-307.

11. Cuéllar, A. Y. D., Sibaja, C. M., & Aguirre, A. U. (2016). Endocrinología clínica de Dorantes y Martínez. Editorial El Manual Moderno.

12. Cervera, V. O. (1994). Testosterona: efectos fisiológicos en el organismo y sus respuestas al entrenamiento de fuerza. Apunts. Educación física y deportes, 3(37), 36-40.

13. Bhasin, S., Storer, T. W., Berman, N., Callegari, C., Clevenger, B., Phillips, J., ... & Casaburi, R. (1996). The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. New England Journal of Medicine, 335(1), 1-7.

14. Bhasin, S., Woodhouse, L., Casaburi, R., Singh, A. B., Bhasin, D., Berman, N., ... & Dzekov, J. (2001). Testosterone dose-response relationships in healthy young men. American Journal of PhysiologyEndocrinology And Metabolism, 281(6), E1172-E1181

15. Tipton, K., & Wolfe, R. R. (2001). Exercise, protein metabolism, and muscle growth. International journal of sport nutrition and exercise metabolism, 11(1), 109-132.

16. Storer, T. W., Magliano, L., Woodhouse, L., Lee, M. L., Dzekov, C., Dzekov, J., ... & Bhasin, S. (2003). Testosterone dose-dependently increases maximal voluntary strength and leg power, but does not affect fatigability or specific tension. The Journal of Clinical Endocrinology & Metabolism, 88(4), 1478-1485.

17. Herbst, K. L., & Bhasin, S. (2004). Testosterone action on skeletal muscle. Current Opinion in Clinical Nutrition & Metabolic Care, 7(3), 271-277.

18. Irie, T., Aizawa, T., & Kokubun, S. (2005). The role of sex hormones in the kinetics of chondrocytes in the growth plate: a study in the rabbit. The Journal of Bone and Joint Surgery. British volume, 87(9), 1278-1284.

19. Trunz-Carlisi, E. (2005). Guía de la musculación. Editorial Hispano Europea.

20. Kvorning, T., Andersen, M., Brixen, K., & Madsen, K. (2006). Suppression of endogenous testosterone production attenuates the response to strength training: a randomized, placebo-controlled, and blinded intervention study. American Journal of Physiology-Endocrinology and Metabolism, 291(6), E1325-E1332.

21. Axell, A. M., MacLean, H. E., Plant, D. R., Harcourt, L. J., Davis, J. A., Jimenez, M., ... & Zajac, J. D. (2006). Continuous testosterone administration prevents skeletal muscle atrophy and enhances resistance to fatigue in orchidectomized male mice. American Journal of Physiology-Endocrinology and Metabolism, 291(3), E506- E516.

22. Kadi, F. (2008). Cellular and molecular mechanisms responsible for the action of testosterone on human skeletal muscle. A basis for illegal performance enhancement. British journal of pharmacology, 154(3), 522- 528.

23. Vingren, J. L., Kraemer, W. J., Ratamess, N. A., Anderson, J. M., Volek, J. S., & Maresh, C. M. (2010). Testosterone physiology in resistance exercise and training. Sports medicine, 40(12), 1037-1053.

24. Pardo Beltrán, J. O. (2013). Efectos del entrenamiento de la fuerza en plataforma vibratoria sobre los miembros inferiores en personas sedentarias (Doctoral dissertation, Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación).

25. Bremner, W. J., Vitiello, M. V., & Prinz, P. N. (1983). Loss of circadian rhythmicity in blood testosterone levels with aging in normal men. The Journal of Clinical Endocrinology & Metabolism, 56(6), 1278-1281.

26. San Juan, O. C. (2003). Cambios hormonales de la testosterona y el cortisol en respuesta al entrenamiento de resistencia en atletismo. Universidad de Valladolid.

27. Craig, B. W., Brown, R., & Everhart, J. (1989). Effects of progressive resistance training on growth hormone and testosterone levels in young and elderly subjects. Mechanisms of ageing and development, 49(2), 159- 169.

28. Pyka, G., Taaffe, D. R., & Marcus, R. (1994). Effect of a sustained program of resistance training on the acute growth hormone response to resistance exercise in older adults. Hormone and metabolic research, 26(07), 330-333.

29. Wideman, L., Weltman, J. Y., Hartman, M. L., Veldhuis, J. D., & Weltman, A. (2002). Growth hormone reléase during acute and chronic aerobic and resistance exercise: recent findings. Sports medicine, 32, 987-1004.

30. Stokes, K. (2003). Growth hormone responses to sub-maximal and sprint exercise. Growth hormone & IGF research, 13(5), 225-238.

31. Macaluso, A., & De Vito, G. (2004). Muscle strength, power and adaptations to resistance training in older people. European journal of applied physiology, 91(4), 450-472.

32. Garcia, J. M., Merriam, G. R., & Kargi, A. Y. (2019). Growth hormone in aging. Endotext [Internet].

33. Vanhelder, W., Radomski, M. W., & Goode, R. C. (1984a). Growth hormone responses during intermittent weight lifting exercise in men. European journal of applied physiology and occupational physiology, 53, 31-34.

34. Vanhelder, W. P., Goode, R. C., & Radomski, M. W. (1984b). Effect of anaerobic and aerobic exercise of equal duration and work expenditure on plasma growth hormone levels. European journal of applied physiology and occupational physiology, 52(3), 255-257.

35. Kraemer, W. J., Marchitelli, L., Gordon, S. E., Harman, E., Dziados, J. E., Mello, R., ... & Fleck, S. J. (1990). Hormonal and growth factor responses to heavy resistance exercise protocols. Journal of Applied Physiology, 69(4), 1442-1450.

36. Peake, J. M., Tan, S. J., Markworth, J. F., Broadbent, J. A., Skinner, T. L., & Cameron-Smith, D. (2014). Metabolic and hormonal responses to isoenergetic high-intensity interval exercise and continuous moderateintensity exercise. American Journal of Physiology-Endocrinology and Metabolism, 307(7), E539-E552.

37. Rooijackers, H. M., Wiegers, E. C., van der Graaf, M., Thijssen, D. H., Kessels, R. P., Tack, C. J., & de Galan, B. E. (2017). A single bout of high-intensity interval training reduces awareness of subsequent hypoglycemia in patients with type 1 diabetes. Diabetes, 66(7), 1990-1998.

38. Kraemer, W. J., Gordon, S. E., Fleck, S. J., Marchitelli, L. J., Mello, R., Dziados, J. E., ... & Fry, A. C. (1991). Endogenous anabolic hormonal and growth factor responses to heavy resistance exercise in males and females. International journal of sports medicine, 12(02), 228-235.

39. Mulligan, S. E., Fleck, S. J., Gordon, S. E., Koziris, L. P., Triplett-McBride, N. T., & Kraemer, W. J. (1996). Influence of resistance exercise volume on serum growth hormone and cortisol concentrations in women. The Journal of strength & conditioning research, 10(4), 256-262.

40. Tanimoto, M., Madarame, H., & Ishii, N. (2005). Muscle oxygenation and plasma growth hormone concentration during and after resistance exercise: Comparison between “KAATSU” and other types of regimen. International Journal of KAATSU Training Research, 1(2), 51-56.

41. Smilios, I., Pilianidis, T., Karamouzis, M., & TOKMAKIDIS, S. P. (2003). Hormonal responses after various resistance exercise protocols. Medicine & Science in Sports & Exercise, 35(4), 644-654.

42. Beaven, C. M., Gill, N. D., & Cook, C. J. (2008). Salivary testosterone and cortisol responses in profesional rugby players after four resistance exercise protocols. The Journal of Strength & Conditioning Research, 22(2), 426-432.

43. Kraemer, W. J., Häkkinen, K., Newton, R. U., McCormick, M., Nindl, B. C., Volek, J. S., ... & Farrell, P. A. (1998). Acute hormonal responses to heavy resistance exercise in younger and older men. European journal of applied physiology and occupational physiology, 77(3), 206-211.

44. Steib, S., Schoene, D., & Pfeifer, K. (2010). Dose-response relationship of resistance training in older adults: a meta-analysis. Medicine & Science in Sports & Exercise, 42(5), 902-914.

45. HUNTER, G. R., WETZSTEIN, C. J., Mclafferty Jr, C. L., ZUCKERMAN, P. A., LANDERS, K. A., & BAMMAN, M. M. (2001). High-resistance versus variable-resistance training in older adults. Medicine & science in sports & exercise, 33(10), 1759-1764.

46. Kalapotharakos, V. I., Michalopoulos, M., Tokmakidis, S. P., Godolias, G., & Gourgoulis, V. (2005). Effects of a heavy and a moderate resistance training on functional performance in older adults. The Journal of Strength & Conditioning Research, 19(3), 652-657.

47. Henwood, T. R., Riek, S., & Taaffe, D. R. (2008). Strength versus muscle power-specific resistance training in community-dwelling older adults. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 63(1), 83-91.

Gracias David Poma