Matsuda J J, Zernicke R F, Vailas A C, Pedrini V A, Pedrini-Mille A, Maynard J A
J Appl Physiol (1985). 1986 Jun;60(6):2028-34. doi: 10.1152/jappl.1986.60.6.2028.
To investigate the adaptive responses of immature bone to increased loads, young (3-wk-old) White Leghorn roosters were subjected to moderately intense treadmill running for 5 or 9 wk. The training program induced significant increases in maximal O2 consumption and muscle fumarase activity in the 12-wk-old birds, demonstrating that growing chickens have the ability to enhance their aerobic capacity. The structural and mechanical properties of the runners' tarsometatarsus bones were compared with sedentary age-matched controls at 8 and 12 wk of age. Suppression of circumferential growth occurred with exercise at both ages, whereas exercise enhanced middiaphysial cortical thickening, especially on the bones' concave surfaces. Although cross-sectional area moments of inertia did not change with exercise, significant decreases in bending stiffness, energy to yield, and energy to fracture were observed. It was concluded that strenuous exercise may retard long-bone maturation, resulting in more compliant bones.
为了研究未成熟骨骼对增加负荷的适应性反应，对年轻（3周龄）的白来航公鸡进行适度强度的跑步机跑步训练，持续5周或9周。该训练计划使12周龄的鸡的最大耗氧量和肌肉富马酸酶活性显著增加，表明生长中的鸡有能力提高其有氧能力。将跑步鸡的跗跖骨的结构和力学性能与8周龄和12周龄的久坐不动的同龄对照鸡进行比较。在两个年龄段，运动都会抑制圆周生长，而运动则会增强骨干中部皮质增厚，尤其是在骨骼的凹面。虽然运动后惯性矩的横截面积没有变化，但观察到弯曲刚度、屈服能量和断裂能量显著降低。得出的结论是，剧烈运动可能会延缓长骨成熟，导致骨骼更易弯曲。
