一生骨頭強化計劃──30歲之前以運動建立高峰骨質密度及骨質含量

Lifetime bone strengthening program-Building optimal bone mineral density and content through exercise before the age of

骨質疏鬆患者逆轉似乎相當困難，因此對於骨頭的強化必需進行策略性規劃，尤其是一生的骨質強化。為了預防骨質疏鬆，在30歲之前必須建立最佳化的骨質密度及骨質含量。骨質強化愈早愈好，否則，除錯失青春期的長期骨質含量疊加堆積外，年齡愈大對於應變反應愈遲鈍，強化骨質密度及骨質含量愈形困難。為了預防骨質疏鬆，30歲前宜建立最大的高峰骨量(peak bone mass)。從骨質的發展而言，此階段分成2期，其一為青春期之前至青春末期的快速成長期，這是一生中骨質密度及骨質含量發展最速期；其二為青春末期至30歲之微幅成長期，此期仍屬骨質成長期，唯增幅較低。在承受力學應變(strain)之下，骨頭得以調整質量及結構；應變形式有四種，即應變幅度(strain magnitude)、應變率(strain rate)、負重頻率(loading frequency)及非習慣性應變分佈(strain distribution)。本文探討這些應變變項衍生之訓練法，及其對於骨質產生適應之影響。運動是強化骨頭的關鍵方法，其訓練法有四大類，即阻力訓練、負重(weight-bearing)訓練、衝擊式訓練法(impact training)與全身振動(whole body vibration, WBV)訓練法。相較於成人，少年或青少年骨頭對於力學刺激較為敏銳，這些方法似乎較能收提升之效。四種訓練法亦可組成複合訓練法(complex training)，各類型複合訓練法應該更具潛力，然而仍需試驗證明其效果，並找出最佳訓練組合。持續性有氧運動訓練效果不及上述訓練法，過量之非衝擊性耐力訓練甚至對骨質產生負面效果。強化心肺功能的有氧耐力訓練，並非是強化骨質的好選項，然而，如要同時提升心肺與骨頭，各類型的間歇訓練法可能是個好選項。

Once people lose their bone mass substantially and become patients with osteoporosis, the reversal of the condition is nearly impossible. Thus, strategic planning for strengthening bone structures for life is essential. To prevent osteoporosis, people must build optimal bone mass by the age of 30 and store as much bone mass as possible. The strengthening of bone structure should begin as early as possible. During adolescence, the bone mass accumulates substantially. However, as people age, their bone reaction to strain becomes dull, and strengthening bone mass becomes more difficult. To prevent osteoporosis, one should establish optimal bone structures and store maximum bone mass by the age of 30. Before the age of 30, bone development can be divided into two stages. The first stage is before adolescence to late adolescence. This is the period in one’s life during which bone mass develops the fastest, so it is the key to building bone mass. The second stage is from late adolescence to the age of 30. This stage is still a bone mass growth period, but the growth rate is much lower. To bear strain, bones must adjust their mass and structure. Strain has four types, namely strain magnitude, strain rate, loading frequency, and non-habitual strain distribution. This study explored the training methods derived from these strains and their impacts on bone adaptations. Exercise is the key to strengthening bone mass. This study employed 4 exercise training methods, namely resistance training, weight-bearing, impact training, and wholebody vibration. Compared to adults, adolescence’s bones were more acute to mechanical stimulations, and these methods seemed to be able to increase bone mass. These 4 training methods can be combined into complex trainings. Complex trainings are assumed to have greater potential than individual trainings, but their results and the optimal complex training combination still must be tested and identified. Compared to the aforementioned training methods, continuous aerobic exercise training had inferior results. Excessive non-impact endurance training even generated negative impact on bone mass. Thus, aerobic endurance training that reinforces cardiopulmonary function is not ideal for strengthening bone mass. To simultaneously improve cardiopulmonary function and bone mass, interval training might be a favorable option.