Back pain is common among elite cyclists. Experiences of athletes and observations of coaches show that it may influence training quality and sometimes even limit performance during competition. Therefore the following study questions were investigated: 1) How many athletes of the Swiss cycling national teams suffer back pain during training or competition? 2) How good is athletes’ core strength? 3) What correlation exists between back pain and core strength? 4) Does an intensified core strength training reduce back pain? A total of 111 elite cyclists, 45 athletes (38 m, 7f; 19.6 ± 3.5y) of technical disciplines (BMX, Trial, Downhill, 4X) and 66 athletes (39 m, 27f; 19.5 ± 5.8y) of endurance disciplines (road, MTB, Cyclo-cross) all members of Swiss cycling national teams, took part in in the study.