In this meta-analysis, we investigated the effect of resistance training (RT) alone or included in a multimodal training on physical frailty outcomes, and whether different variables of RT prescription affect these outcomes. We identified 15 relevant studies searching through MEDLINE, Cochrane Central Register of Controlled Trials, SPORTDiscus, and PEDro database. Postintervention standardized mean difference scores were computed and combined using fixed effects meta-analysis. Analyses have shown positive effects of interventions on maximum strength, gait speed, and Timed Up and Go test. Further analyses have shown significant greater effect of shorter periods on maximum strength. Regarding RT prescription, percentage of one-repetition maximum showed significant effect on physical variables, whereas RT based on rate of perceived effort presented lower effect in the Timed Up and Go test. Although multimodal training is an effective intervention to increase physical capacity, caution should be taken regarding the period and the method to control RT intensity to optimize enhancements in frail older people.