Yancey Antronette K, McCarthy William J, Harrison Gail G, Wong Weng Kee, Siegel Judith M, Leslie Joanne
Department of Health Services, UCLA School of Public Health, Los Angeles, California 90095, USA.
J Womens Health (Larchmt). 2006 May;15(4):412-29. doi: 10.1089/jwh.2006.15.412.
This study tested the efficacy of an 8-week culturally targeted nutrition and physical activity intervention on body composition.
A randomized, attention-controlled, two-group trial was conducted in a blackowned commercial gym with a sample of 366 predominantly healthy, obese African American women. A free 1-year membership to the study site gym was provided to participants in both groups. Data were collected at baseline, 2, 6, and 12 months.
Sample retention at 1 year was 71%. Between-group longitudinal analysis including only participants with complete data revealed a trend toward weight stability in the intervention group at 2 months compared with controls (+0.05 kg/m(2), p = 0.75; +0.32 kg/m(2), p = 0.08, respectively), disappearing at 12 months (+1.37 kg/m(2), p = 0.0001; +1.02 kg/m(2), p = 0.001, respectively). Within-group analysis demonstrated that intervention and control participants' fitness (1-mile run-walk) improved by 1.9 minutes (p = 0.0001) and 2.3 minutes (p = 0.0001), respectively, at 12 months. Mixed model regression analyses demonstrated a significant main effect of the intervention on fitness (p = 0.0185) and a marginally significant effect on body mass index (BMI) (p = 0.057), at 2 months, disappearing by 6 months. By 12 months, however, the controls exhibited a significant advantage in waist circumference stability compared with intervention participants (+1.1 cm, p = 0.2763; +2.1 cm, p = 0.0002, respectively).
The intervention produced modest short-term improvements in body composition, but the economic incentive of a free 1-year gym membership provided to all participants was a more potent intervention than the education and social support intervention tested. However, longer-term fitness enhancement remains elusive and demands research and policy attention. These findings have policy implications in that employer-/insurer-subsidized gym memberships may require interventions targeting other levels of change (e.g., physical or social/environmental) to foster sustainable fitness improvements.
本研究测试了一项为期8周的针对特定文化背景的营养和身体活动干预对身体成分的效果。
在一家黑人拥有的商业健身房进行了一项随机、注意力控制的两组试验，样本为366名主要健康的肥胖非裔美国女性。两组参与者均获得了研究地点健身房的免费1年会员资格。在基线、2个月、6个月和12个月时收集数据。
1年时样本保留率为71%。仅包括具有完整数据的参与者的组间纵向分析显示，与对照组相比，干预组在2个月时体重有稳定趋势（分别为+0.05kg/m²，p = 0.75；+0.32kg/m²，p = 0.08），在12个月时这种趋势消失（分别为+1.37kg/m²，p = 0.0001；+1.02kg/m²，p = 0.001）。组内分析表明，干预组和对照组参与者的体能（1英里跑走）在12个月时分别提高了1.9分钟（p = 0.0001）和2.3分钟（p = 0.0001）。混合模型回归分析表明，干预在2个月时对体能有显著的主效应（p = 0.0185），对体重指数（BMI）有边缘显著效应（p = 0.057），到6个月时效应消失。然而，到12个月时，与干预组参与者相比，对照组在腰围稳定性方面表现出显著优势（分别为+1.1cm，p = 0.2763；+2.1cm，p = 0.0002）。
该干预在短期内对身体成分有适度改善，但向所有参与者提供免费1年健身房会员资格的经济激励措施比所测试的教育和社会支持干预措施更有效。然而，长期的体能增强仍然难以实现，需要研究和政策关注。这些发现具有政策意义，即雇主/保险公司补贴的健身房会员资格可能需要针对其他改变层面（如身体或社会/环境层面）的干预措施，以促进可持续的体能改善。
