A massive 30-year study suggests there may be a sweet spot for strength training: about 90-120 minutes per week. Credit: Shutterstock A long-running study suggests that 90 to 120 minutes of strength (resistance) training each week may be the ideal range for reducing the risk of death. The research, published online in the British Journal of Sports Medicine , followed participants for up to 30 years. The benefits were even greater when strength training was combined with aerobic exercise.