The objectives of this case series study were to test whether an elastic back exosuit could increase a wearer’s endurance when lifting heavy objects and to assess whether lifting more cancels out the exosuit’s risk reduction benefits. We found that 88% of participants increased their lifting repetitions while wearing an exosuit, with endurance increases ranging from 28 to 75%. We then used these empirical data with an ergonomic assessment model based on fatigue failure principles to estimate the effects on cumulative back damage (an indicator of low back disorder risk) when an exosuit is worn and more lifts are performed. Participants exhibited 27–93% lower cumulative back damage when wearing an exosuit. These results confirmed that wearing an exosuit increased participants’ lifting capacity without canceling out injury risk reduction benefits. Back exosuits may make it possible to simultaneously boost productivity and reduce musculoskeletal disorder risks, which is relevant to workers in civilian and defense sectors.