Tiredness or fatigue is one of the most commonly reported symptoms in primary care. There are many different types of fatigue. For example, people may experience fatigue if they cannot sleep well or if they exercise intensively. But there are a lot of older people that feel fatigued all day every day for no apparent reason. This can be distressing and may reduce their quality of life. We don’t currently know a great deal about this problem. For example, we don’t know how daily physical activity levels are related to these experiences of fatigue. On one hand, people who are more active might be more likely to feel tired. But on the other hand, people who experience unrelenting fatigue may be forced to be less active. I am a post-doctoral research fellow working in the Geriatrics, Movement and Stroke (GeMS) group at NTNU, and through collaboration with CERG and the Generation 100 study, I was able to try and find out a bit more about fatigue.