Systematic review evidence indicates muscle fatigue can impair balance and functional task performance in older people. However, it is not known whether fatigue, induced by regular daily life activities, may similarly impair balance and gait and increase the risk of falling in older people. This study will determine whether a busy day of physical activity (‘real world’ fatigue) impacts balance and mobility measures in older people. The sample will comprise 50 participants aged 70+ years who will be asked to attend a balance laboratory before and after a planned busy and planned restful day, presented in random order, one week apart. For the busy day, participants will schedule several daily activities (based on the busiest days they have) into the one day. On the other day, participants will be asked to schedule few activities. Participants will be asked to wear an activity monitor on both restful and busy days to quantify the amount of time sitting, standing and moving. Outcome measure will include self-reported Fatigue and tests of thinking, strength, speed and balance. By specifically investigating everyday fatigue, this study will advance our knowledge from what is known from laboratory studies using ​“artificial” fatiguing protocols to document the effects of real world fatigue on balance, gait and cognition. It will determine the importance of fatigue as a fall risk factor in older people, and provide significant information with respect to the value of mitigating fatigue as a fall prevention strategy.