PROFESSIONAL FOOTBALL (SOCCER) PLAYERS HAVE A MARKEDLY GREATER SKELETAL MINERAL-CONTENT, DENSITY AND SIZE THAN AGE-MATCHED AND BMI-MATCHED CONTROLS

total skeletal bone mineral content (BMC), bone mineral density (BMD), bone size, and body composition were measured by dual-energy x-ray ab sorptiometry (DXA) in all professional male football players of a Ist division team (n = 24) and age- and BMI-matched (n = 22) controls (les s than 3 hours of recreational sport activities per week). Average (+/ -1 SD) age of the athletes was 22.6 +/- 2.5 years. Intensive training is conducted during 48 weeks a year for 20-22 hours/week. The length, of the registered playing career before the study was 8.2 +/- 2.7 year s. Total skeleton BMC was 18.0% (P < 0.001) greater in the football pl ayers. The difference resulted from the sum of 5.2% (P < 0.02) increme nt of bone size and 12.3% (P < 0.001) increment of BMD. The analysis o f skeletal subareas revealed that the difference of the BMC and BMD wa s greater at the level of the pelvis and legs compared with the arms o r trunk. The BMC and BMD of the head was equal for both groups. Also, the bone size of the legs and pelvis was significantly greater for the players compared with controls; there was no difference at the level of the arms or head. Within the group of football players the incremen t of total skeleton BMD was similar in the young players, with less th an 7 years of practice (age 20.6 +/- 0.9 years) compared with relative older players (age 24.6 +/- 1.9) with more than 7 years of practice. Lean body mass was significantly greater in the players (63.3 +/- 4.0 kg) compared with the controls (56.7 +/- 3.6, P < 0.001) whereas fat m ass was markedly lower (9.4 +/- 2.9 kg versus 14.9 +/- 6.3 kg), P < 0. 002). The BMD of the controls was significantly correlated to total we ight, height, and lean mass whereas the BMD of the players was only co rrelated to muscle mass. The calcium intake from dairy products was si milar in both groups. The range of calcium intake was wide among the p layers (184 -2519 mg/day) but it was not significantly correlated to B MD (r = 0.03). Ln conclusion, male professional football players devel op a significant increment of BMC as a result of increased bone size a nd density. This is already present at the end of the second decade an d maintained at least to the end of the third decade in active players . As in other high impact loading sports, the effect on area is specif ic involving mainly the pelvis and legs. The increment was totally unr elated to the calcium intake from dairy products. The fate of the incr eased BMC after intensive training is discontinued should be assessed. However, if the findings of the present cross-sectional study are sup ported by detailed longitudinal investigations, the presently reported observations might be important for the prevention of future osteopor otic fractures.