Employers who seek optimal efficiency and productivity from their older workers should put them on morning shifts. Why? Because recent research at John Morris University in Liverpool, UK, has shown that people aged 47 years and above are less likely to adapt to the disturbed sleep patterns and biorhythms caused by shift work than their younger colleagues. This conclusion has been linked to the decrease in the amplitude of circadian rhythms. Older people tend to get up early and have an earlier energy peak. According to Tom Reilly of the Centre for Exercise Science at the university, who headed the research team, it is not that older people are unsuitable for shift work but that they are likely to make more errors when they work late during the night shifts ( Occupational and Environmental Medicine , Vol 54).