Low bone mineral density and calcium intake in elite cyclists.
OBJECTIVE
High physical activity is associated with larger bone mineral content (BMC) and density (BMD) in young males though competitive road cyclists have been reported to have similar or lower BMD than controls.


METHODS
BMC and BMD were assessed in 73 highly trained (42 professional and 31 elite amateur) road cyclists (CYCLIST; age: 25.8+/-4.3 years; height: 179.7+/-6.3 cm; weight: 71.6+/-6.3 kg; %Fat mass: 9.5+/-3 %; VO(2max): 68.5+/-5.7 mlxkg(-1)xmin(-1)) and in 30 healthy males used as reference (REF: 28.3+/-4.5 years; 176.6+/-6.2 cm; 74.5+/-8.4 kg; 21.3+/-6.1%).


RESULTS
Daily calcium intake estimated from a food-questionnaire was higher in CYCLIST than in REF (942+/-374 vs 753+/-315 mgxd(-1); P=0.008). Compared to REF, CYCLIST had lower L1-L4 BMD (1.004+/-0.125 vs 1.240+/-0.163 gxcm(-2); P<0.0001) and femoral neck BMD (0.986+/-0.132 vs 1.098+/-0.137; P<0.003). In CYCLIST, daily calcium intake is correlated with total BMC and BMD (r=0.27-0.26, P=0.02) and femoral BMD (r=0.35; P=0.002). Divided by tertiles (high, medium and low Ca), CYCLIST with high Ca (1320+/-382 mgxd(-1)) had lower lumbar BMD values (-6.68%; P=0.02) and tended to have lower femoral neck BMD (-4.77%; P=0.09) and radius UD BMD (-5.9%; P=0.07) than REF.


CONCLUSIONS
There was no difference between medium Ca and high Ca for any BMC or BMD parameters. Differences between low Ca and high Ca could be detected only for Total BMC (-8.4%; P=0.01), Pelvis BMD (-7.4%; P=0.01) and femoral neck BMD (-9.9%; P=0.006).
Medelli
Jean
J
Department of Exercise Biology and Sports Medicine, University North Hospital, Amiens Cedex 1, France. medelli. jean@chu-amiens.fr
Shabani
M
M
Lounana
J
J
Fardellone
P
P
Campion
F
F
D015502:Absorptiometry, Photon; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005270:Femur Head / Q000000981:diagnostic imaging / Q000378:metabolism*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000378:metabolism*; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology*; D014142:Track and Field / Q000502:physiology*
D002136:Calcium, Dietary