Although the maximum graded exercise test was not performed after the ET, the differences between the cycle-ergometer workloads from the first and last exercise sessions may be indicative of endurance improvement. A significantly greater workload increase in the OG than in the YG (71.7 ± 36.8% vs. 49.3 ± 21.1%; p = 0.05) was observed.
Because the OG showed lower physical capacity at baseline, they started the ET program with lower absolute workload in almost all exercises (kg and W for resistance and aerobic exercise, respectively), although the initial relative workload was the same for both groups (60% of 1RM and 65-75% of RHR for resistance and aerobic exercise, respectively). Only the biceps curl exercise did not show significant difference in the initial absolute ET workload.
Despite the lower physical capacity of the OG, absolute workload increases were not significantly different between OG and YG with regard to leg press, seated row, knee curl, biceps curl, or cycle-ergometer exercise during the 13 weeks of training. The YG displayed higher absolute workload increase only for the bench press (p = 0.005), shoulder press (p = 0.008), calf raise (p = 0.001), and abdominal (p = 0.003). A tendency toward a higher absolute workload increase for the triceps push-down (p = 0.06) was also observed in the YG (Figure 2).
The RE relative workload increase was not significantly different between YG and OG during the training period, except for a tendency (p = 0.06) toward a greater increase in shoulder press relative workload in the YG. The increase in cycle-ergometer relative workload was different (p = 0.047) between groups, with OG displaying a greater increase during the 13 weeks of training (Figure 3).
The exercise intensity progression method used in this study was found to be safe because no injuries, muscle damage or major muscle pain were observed in the YG and OG during the study period.
The primary finding of this study was that the relative exercise intensity progression was similar in healthy young and older women during 13 weeks of training. Furthermore, our exercise program also promoted improvements in muscle strength and aerobic capacity that were similar between the 2 groups.
To the best of our knowledge, this study is the first in comparing the exercise intensity progression between young and older women. However, other studies have also demonstrated that healthy and frail elderly individuals do not show major orthopedic injuries or muscle damage when performing REs at the same intensity recommended for young adults (10,13,16,24,29). A recent review suggested that healthy older adults may exercise at similar volume and intensity as recommended for healthy young adults; however, information about how exercise intensity should be increased was not provided (11). Our findings support the above recommendation and suggest that healthy older women can safely exercise at similar intensity and increase intensity as recommended for healthy young women.
The 1RM strength improvement shown in this study was unaffected by age, with strength gains from 16.7 to 36.4% for the young and 16.1 to 41.9% for the older women in all 9 movements tested. Strength gains in the older women matched pretraining strength levels in the young women. In agreement with our findings, other studies analyzing age effects on muscle strength gain in response to resistance training demonstrated 17-49%, improvements with no differences between young and older adults, and with posttraining strength in older reaching the pretraining levels of young individuals (16,18,24).
It is important to emphasize that the relative workload increase curve for aerobic exercise was greater for OG than YG. There are at least 2 hypotheses that explain this finding. First, OG could acquire increased biomechanical efficiency during training period. Oxygen uptake and cardiovascular response to exercise correlates with biomechanical efficiency and the quantity of muscle recruited (7,26). Poor cycle ergometry (CE) and neuromuscular recruitment at the beginning of the study, because of the longer periods of physical inactivity (11), could yield greater cardiovascular response to exercise in older women; thus, a greater improvement in the neuromuscular recruitment in older women may occur during the training period and likely resulting in the increased cardiovascular adaptation to the CE observed in OG.
The second hypothesis is based on the blood lactate response to exercise. It has been shown that maximum steady-state lactate levels decline with aging (21). On the other hand, it is known that aerobic ET performed at higher blood lactate levels is associated with greater improvements in aerobic performance (5,34). According to this, older women probably exercised closer to the maximum steady-state lactate than the young women, and this may have promoted a faster cardiovascular adaptation to the CE.
Dr. Emmanuel G. Ciolac has been supported by Sociedade de Cardiologia do Estado de Sa˜o Paulo.
1. American College of Sports Medicine. ACSM stand position on exercise and physical activity for older
adults. Med Sci Sports Exerc
41: 1510-1530, 2009.
2. American College of Sports Medicine. ACSM position stand on the recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc
30: 975-991, 1998.
3. American College of Sports Medicine. ACSM position stand on progression models in resistance training. Med Sci Sports Exerc
41: 687-780, 2009.
4. American Heart Association. AHA scientific sStatement on exercise standards for testing and training: A statement for healthcare professionals from the American heart association. Circulation
140: 1694-1740, 2001.
5. Belman, MJ and Gaesser, GA. Exercise training below and above the lactate threshold in the elderly. Med Sci Sports Exerc
23: 562-568, 1991.
6. Binder, E, Schechtman, K, Ehsani, A, Steger-May, KMA, Brown, M, Sinacore, DR, Yarasheski, KE, and Holloszy, JO. Effects of exercise training on frailty in community-dwelling elderly adults: Results of a randomized, controlled trial. J Am Geriatr Soc
50: 1921-1928, 2002.
7. Cavanagh, PR and Kram, R. Mechanical and muscle factors affecting the efficiency of human movement. Med Sci Sports Exerc
17: 326-331, 1985.
8. Ciolac, EG and Guimarães, GV. The role of resistance training on ageing. Rev Soc Cardiol Estado de São Paulo
12: 5-26, 2002.
9. Conboy, IM, Conboy, MJ, Smythe, GM, and Rando, TA. Notch-mediated restoration of regenerative potential to aged muscle. Science
302: 1575-1577, 2003.
10. Fiatarone, MA, O'Neil, EF, Ryan, ND, Clements, KM, Solares, GR, Nelson, ME, Roberts, SB, Kehayias, JJ, Lipsitz, LA, and Evans, WJ. Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med
330: 1769-1775, 1994.
11. Fiatarone-Singh, MA. Exercise comes of age: Rationale and recommendations for a geriatric exercise prescription. J Gerontol A Biol Sci Med Sci
57: M262-M282, 2002.
12. Fletcher, GF, Balady, GJ, Amsterdam, EA, Chaitman, B, Eckel, R, Fleg, J, Froelicher, VF, Leon, AS, Pina, IL, Rodney, R, Simons-Morton, DA, Williams, MA, and Bazzarre, T. Exercise standards for testing and training: A statement for healthcare professionals from the American Heart Association. Circulation
104: 1694-1740, 2001.
13. Häkkinen, K, Newton, RU, Gordon, SE, McCormik, M, Volek, JS, Nindl, BC, Gostshalk, LA, Campbell, WW, Evans, WJ, Häkkinen, A, Humphries, BJ, and Kraemer, WJ. Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older
people. J Gerontol A Biol Sci Med Sci
53: B415-B423, 1998.
14. Hunter, GR, Wetzstein, CJ, Mclafferty, CL Jr, Zuckerman, PA, Landers, KA, and Bamman, MM. High-resistance versus variable-resistance training in older
adults. Med Sci Sports Exerc
33: 1759-1764, 2001.
15. Karvonen, M, Kentala, K, and Mustala, O. The effects of training on heart rate: A longitudinal study. Ann Med Exper Biol Fenn
35: 307-315, 1957.
16. Knight, CA and Kamen, G. Adaptations in muscular activation of the knee extensor muscle with strength training in young and older
adults. J Electromyogr Kinesiol
11: 405-412, 2001.
17. Kohrt, W, Malley, M, Coggan, A, Spina, RJ, Ogawa, T, Ehsani, AA, Bourey, RE, Martin, WH III, and Holloszy, JO. Effects of gender, age, and fitness level on response of O2
max to training in 60-71 yr olds. J Appl Physiol
71: 2004-2011, 1991.
18. Kosek, DJ, Kim, J, Petrella, JK, Cross, JM, and Bamman, MM. Efficacy of 3 days/wk resistance training on myofiber hypertrophy and myogenic mechanism in young vs. older
adults. J Appl Physiol
101: 531-544, 2006.
19. Lord, SR, Ward, JA, and Williams, P. Exercise effect on dynamic stability in older
women: A randomized controlled trial. Arch Phys Med Rehabil
77: 232-236, 1996.
20. Marsh, DR, Criswell, DS, Carson, JA, and Booth, FW. Myogenic regulatory factors during regeneration of skeletal muscle in young, adult, and old rats. J Appl Physiol
21. Mattern, CO, Gutilla, MJ, Bright, DL, Kirby, TE, Hinchcliff, KW, and Devor, ST. Maximal lactate steady state declines during the aging
process. J Appl Physiol
95: 2576-2582, 2003.
22. Miller, JP, Pratley, RE, Goldber, AP, Gordon, P, Rubin, M, Treuth, MS, Ryan, AS, and Hurley, BF. Strength training increases insulin action in healthy 50-to 65-yr-old men. J Appl Physiol
77: 1122-1127, 1994.
23. Nelson, ME, Fiatarone, MA, Morganti, CM, Trice, I, Greenberg, RA, and Evans, WJ. Effects of high-intensity strength training on multiple risk factors osteoporotic fractures: A randomized controlled trial. JAMA
272: 1909-1914, 1994.
24. Newton, RU, Häkkinen, K, Häkkinen, A, McCormick, M, Volek, J, and Kraemer, WJ. Mixed-methods resistance training increases power and strength of young and older
men. Med Sci Sports Exerc
34: 1367-1375, 2002.
25. Pate, RR, Pratt, M, Blair, SN, Haskell, WL, Macera, CA, Bouchard, C, Buchner, D, Ettinger, W, Heath, GW, King, AC, Kriska, A, Leon, AS, Marcus, BH, Morris, J, Paffenbarger, RS Jr, Patrick, K, Pollock, ML, Rippe, JM, Sallis, J, and Wilmore, JH. Physical activity and public health: A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA
273: 402-407, 1995.
26. Perry, SR, Housh, TJ, Johnson, GO, Ebersole, KT, Bull, AJ, Evetovich, TK, and Smith, DB. Mechanomyography, electromyography, heart rate, and ratings of perceived exertion during incremental cycle ergometer. J Sports Med Phys Fitness
41: 183-188, 2001.
27. Pratley, R, Nickas, B, Rubin, M, Miller, J, Smith, A, Smith, M, Hurley, B, and Goldberg, A. Strength training increases resting metabolic rate and norepinephrine levels in healthy 50- to 65-year-old men. J Appl Physiol
76: 133-137, 1994.
28. Roth, SM, Ivey, FM, Martel, GF, Lemmer, JT, Hurlbut, DE, Siegel, EL, Metter, EJ, Fleg, JL, Fozard, JL, Kostek, MC, Wernick, DM, and Hurley, BF. Muscle size response to strength training in young and older
men and women. J Am Geriatr Soc
49: 1428-1433, 2001.
29. Roth, SM, Martel, GF, Ivey, FM, Lemmer, JT, Metter, EJ, Hurley, BF, and Rogers, MA. High-volume, heavy-resistance strength training and muscle damage in young and older
women. J Appl Physiol
88: 1112-1118, 2000.
30. Roubenoff, R. Origins and clinical relevance of sarcopenia. Can J Appl Physiol
26: 78-89, 2001.
31. Seynnes, O, Fiatarone-Singh, MA, Hue, O, Pras, P, Legros, P, and Bernard, PL. Physiological and functional responses to low-moderate versus high-intensity progressive resistance training in frail elders. J Gerontol A Biol Sci Med Sci
59A: 503-509, 2004.
32. Singh, N, Clements, K, and Fiatarone-Singh, M. The efficacy of exercise as a long-term antidepressant in the elderly: A randomized controlled trial. J Gerontol A Med Sci
56A: M1-M8, 2001.
33. Tamaki, T, Uchiyama, S, Uchiyama, Y, Akatsuka, A, Yoshimura, S, Roy, RR, and Edgerton, VR. Limited myogenic response to a single bout of weight-lifting exercise in old rats. Am J Physiol Cell Physiol
278: C1143-C1152, 2000.
34. Weltman, A, Seip, RL, Snead, D, Weltman, JY, Haskvitz, EM, Evans, WS, Veldhuis, JD, and Rogol, AD. Exercise training at and above the lactate threshold in previously untrained women. Int J Sports Med
13: 257-263, 1992.