Background

Recreational cycling is a popular activity which stimulates and improves cardiovascular fitness. The corresponding benefits for bone are unclear.

Purpose

This study examined the effect of running (high-impact) vs. cycling (low-impact), at the same moderate-to-vigorous exercise intensity, on markers of bone formation (N-terminal propeptide of type I collagen, PINP) and bone resorption (C-telopeptide of type I collagen, CTX-1), a non-collagenous bone remodeling marker (osteocalcin), as well as bone-modulating factors, including parathyroid hormone (PTH), irisin (myokine) and sclerostin (osteokine).

Methods

Thirteen healthy men (23.7 ± 1.0 y) performed two progressive exercise tests to exhaustion (peak VO₂) on a cycle ergometer (CE) and on a treadmill (TM). On subsequent separate days, in randomized order, participants performed 30-min continuous running or cycling at 70% heart rate reserve (HRR). Blood was drawn before, immediately post- and 1 h into recovery.

Results

PTH transiently increased (CE, 51.7%; TM, 50.6%) immediately after exercise in both exercise modes. Sclerostin levels increased following running only (27.7%). Irisin increased following both running and cycling. In both exercise modes, CTX-1 decreased immediately after exercise, with no significant change in PINP and osteocalcin.

Conclusion

At the same moderate-to-vigorous exercise intensity, running appears to result in a greater transient sclerostin response compared with cycling, while the responses of bone markers, PTH and irisin are similar. The longer-term implications of this differential bone response need to be further examined.

中文翻译：

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硬化蛋白和骨转换标志物对健康男性以相同的中等至剧烈运动强度骑自行车和跑步的反应

背景

休闲自行车是一项受欢迎的活动，可以刺激和改善心血管健康。对骨骼的相应益处尚不清楚。

目的

本研究检验了在相同的中等至剧烈运动强度下，跑步（高冲击力）与骑自行车（低冲击力）对骨形成标志物（I 型胶原蛋白的 N 末端前肽，PINP）和骨吸收（I 型胶原的 C 端肽，CTX-1）、非胶原骨重塑标志物（骨钙素）以及骨调节因子，包括甲状旁腺激素 (PTH)、鸢尾素（肌动蛋白）和硬化蛋白（骨因子） ）。

方法

13 名健康男性 (23.7 ± 1.0 岁) 在自行车测力计 (CE) 和跑步机 (TM) 上进行了两次累进性运动测试，直至力竭（峰值 VO _{2 ）。}在随后的不同日子里，参与者以随机顺序进行 30 分钟的连续跑步或以 70% 的心率储备 (HRR) 骑自行车。在恢复之前、之后立即和恢复后 1 小时抽取血液。

结果

PTH 在两种运动模式下运动后立即瞬时增加（CE，51.7%；TM，50.6%）。仅跑步后硬化蛋白水平增加（27.7%）。跑步和骑自行车后鸢尾素增加。在两种运动模式下，运动后 CTX-1 立即下降，而 PINP 和骨钙素没有显着变化。

结论

在相同的中等至剧烈运动强度下，与骑自行车相比，跑步似乎会导致更大的瞬时硬化蛋白反应，而骨骼标志物、PTH 和鸢尾素的反应相似。这种不同的骨反应的长期影响需要进一步研究。