Performance losses in middle age are often attributed to biological ageing. Running-time analyses in long-distance runners aged 20–80 years (n > 500,000) show that in fact no significant performance reductions occur before the age of 54 years. Moreover, further investigations carried out in the context of the PACE project (http://www.dshs-koeln.de/en/pace) reveal that performance losses in middle age are primarily caused by unhealthy lifestyle and lack of training. The increasing number of overweight, untrained individuals indicates that current preventive efforts are insufficient. Maintaining health and performance is becoming an urgent problem in modern society and a solution to this cost-intensive problem is not yet in sight.