Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women. Issue 6 (June 2020)

• Record Type: Journal Article
• Authors: Nascimento, Matheus A.; Silva, Danilo R.P.; Ribeiro, Alex S.; Pina, Fábio L.C.; Gerage, Aline M.; Gobbo, Luís A.; Mayhew, Jerry L.; Cyrino, Edilson S.
• Is Part Of: Journal of strength and conditioning research. Volume 34:Issue 6(2020)
• Publication Date: 2020-06
• Subjects: DXA -- BIA -- strength training -- BMI; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000002581
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res 34(6): 1700–1708, 2020—The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m −2 ) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10–15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM ( F = 244.63, p < 0.001), although all equations had high correlations with DXA ( r = 0.78–0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM ( F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.