The effects of obesity, age, and relative workload levels on handgrip endurance

• The impacts of obesity and age on handgrip endurance across relative workload levels were examined.
• Obesity was associated with increased fatigability and perception of effort in younger adults.
• Current prediction models overestimate endurance times for the younger obese adults.

The purpose of the study was to examine obesity and age effects on handgrip endurance across a range of relative workload levels. Forty-five non-obese and obese younger and older females performed fatiguing handgrip exercises at 20, 40, 60, and 80% of relative handgrip strength. The younger obese group demonstrated ∼7% greater strength, 32% shorter endurance times, and ∼34% faster rate of strength loss, accompanied by heightened perception of effort, than the younger non-obese group. However, these obesity-related differences were not observed in the older age group. Moreover, there were no interactions between relative workload levels, obesity, and age on any of the fatigue measures. Findings obtained here suggest that work-rest schedules computed from existing force endurance prediction models may not be protective of the younger obese working population.