Purpose: To determine the effect of a 12-month moderate resistance training program on phenotypic and functional immunological parameters of previously sedentary, clinically healthy, elderly women.
Methods: A total of 42 clinically healthy, sedentary females (aged 60-77 yr old) were randomly assigned to either a moderate-intensity resistance training program or a control group during a 12-month longitudinal, randomized, controlled, intervention study. Resistance training program consisted of three sets of 12 repetitions at 54.9 ± 2.4% 1RM for five different exercises performed three times per week during 12 months. Natural killer cell cytotoxic activity (NKCA), lymphoproliferative response to the mitogen phytohemaglutinin (PHA), and quantification of the lymphocytes (CD3+, CD3−CD19+, CD56+) and subpopulations (CD4+, CD8+, CD56dim, CD56bright) as well as cellular expression molecules (CD25+, CD28+, CD45RA+, CD45RO+, CD69+, CD95+, HLA-DR+) were determined by immunological assays.
Results: The experimental group increased muscle strength in 44% and 48% after 6 and 12 months, respectively (P < 0.05). There were no statistically significant differences between the groups or according to the time for quantitative (CD3+, CD3−CD19+, CD56+, CD4+, CD8+, CD45RA+, CD45RO+, CD56dim, CD56bright, CD95+, CD28+, CD25+, CD69+, HLA-DR+) and functional immunological parameters (natural killer cell cytotoxic activity and lymphoproliferative response).
Conclusion: A 12-month moderate resistance training program increases muscle strength, but it does not change immune phenotypic and functional parameters of previously sedentary, clinically healthy, elderly women.
1Department of Experimental Physiopathology, 2Laboratory of Investigation in Dermatology and Immunodeficiencies, and 3Clinics Hospital, Medical School of the University of S`o Paulo, S`o Paulo, BRAZIL
Address for correspondence: Gil Benard, Tropical Medicine Institute, IMT, #470 Enéas de Carvalho Aguiar Avenue, Third floor, 05403-000, São Paulo, SP, Brazil; E-mail: firstname.lastname@example.org.
Submitted for publication April 2007.
Accepted for publication July 2007.