Effects of short term elastic resistance training on muscle mass and strength in untrained older adults: a randomized clinical trial.
BACKGROUND
The current recommendations on resistance training involving older adults have reported an improvement of body composition variables. Despite this, there is a lack of knowledge on how elastic resistance training (ERT) affects the muscle mass in older adults population. The purpose of this study was to determine the effects of a short-term ERT on muscle mass of health and untrained older adults.


METHODS
Forty older adults were randomized into two groups of 20 individuals each: Control Group (CG = 66.2 ± 6.6 years) and Training Group (TG = 69.1 ± 6.3 years). TG underwent an ERT twice a week during 8 weeks and control group did not receive any specific intervention. The primary outcome was the upper and lower limbs muscle mass, measured by Dual-energy x-ray absorptiometry. The secondary outcomes were knee isokinetic peak torque (PT) at 60°/s and 120°/s speeds and isometric handgrip strength. A 2×2 mixed model (group [TG and CG] × time [pre and post]) analysis of variance (ANOVA) was applied to determine the effect on primary and secondary outcomes.


RESULTS
The results of the ANOVA showed no significant effects in group x time interaction for (1) upper limbs fat free mass (F [1.38] = 1.80, p = 0.19, effect size [ES] = 0.1) and for (2) lower limbs fat free mass (F [1.38] = 0.03, p = 0.88, ES = 0.02). Regarding muscle strength, the ANOVA showed no significant effects in group x time interaction for (3) PT at 60°/s (F [1.38] = 0.33, p = 0.56, ES = 3.0), for (4) PT at 120°/s (F [1.38] = 0.80, p = 0.38, ES = 4.1) and for handgrip strength (F [1.38] = 0.65, p = 0.42-value, ES = 0.9). Analysis of PT in TG showed a significant change of 4.5%, but only at 120°/s (p = 0.01) when comparing pre and post-training (time interaction).


CONCLUSIONS
Eight weeks of ERT did not show significant changes in muscle mass and strength of untrained older adults.


BACKGROUND
NCT02253615 (09/25/14).
University of Brasilia, College of Physical Therapy, Campus Ceilândia, QNN 14, Ceilância Sul, DF, 72220-140, Brazil. wrmartins@me.com.|University of Brasilia, College of Physical Education, Campus Universitário Darcy Ribeiro, Brasilia, DF, 70904-970, Brazil. wrmartins@me.com.
Wagner Rodrigues
WR
Martins
University of Brasilia, College of Physical Education, Campus Universitário Darcy Ribeiro, Brasilia, DF, 70904-970, Brazil. mari7@unb.com.
Marisete Peralta
MP
Safons
University of Brasilia, College of Physical Education, Campus Universitário Darcy Ribeiro, Brasilia, DF, 70904-970, Brazil. martim@unb.br.
Martim
M
Bottaro
University of Brasilia, College of Physical Therapy, Campus Ceilândia, QNN 14, Ceilância Sul, DF, 72220-140, Brazil. juscelino@me.com.
Juscelino Castro
JC
Blasczyk
University of Brasilia, College of Physical Therapy, Campus Ceilândia, QNN 14, Ceilância Sul, DF, 72220-140, Brazil. lrdiniz@gmail.com.
Leonardo Rios
LR
Diniz
Physical Education Department, Federal University of Pernambuco, Jornalista Anibal Fernandes Av, Campus Recife 50670-901, Recife, PE, Brazil. romulo.fonseca@ufpe.br.
Romulo Maia Carlos
RM
Fonseca
University of Brasilia, College of Physical Therapy, Campus Ceilândia, QNN 14, Ceilância Sul, DF, 72220-140, Brazil. anaclara@unb.br.
Ana Clara
AC
Bonini-Rocha
University of Brasilia, College of Physical Education, Campus Universitário Darcy Ribeiro, Brasilia, DF, 70904-970, Brazil. rjaco@unb.br.
Ricardo Jacó
RJ
de Oliveira
D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000704:Analysis of Variance; D001823:Body Composition; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology; D009133:Muscular Atrophy / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D055070:Resistance Training / Q000379:methods*; D016896:Treatment Outcome; D034941:Upper Extremity / Q000000981:diagnostic imaging / Q000503:physiopathology