Have you ever wished you could take a pill that mimics all the positive benefits of exercise without ever having to set foot on the Stairmaster?

Scientists at the Howard Hughes Medical Institute have identified two drugs that imitate many of the physiological effects of working out at the gymnasium, such as increasing the ability of cells to burn fat.

The drugs could offer protection against obesity and metabolic disorders, in addition to helping counter the effects of muscle-wasting diseases such as muscular dystrophy.

The drugs, which can be given orally, work by genetically reprogramming muscle fibres so they use energy more efficiently and can contract repeatedly without fatigue.

In laboratory experiments reported in the journal Cell, mice taking the drugs ran faster and longer than normal animals on treadmill tests. For instance, mice given AICAR, one of the two drugs, ran 44 per cent longer than untreated animals.

The second compound, GW1516, had a more dramatic impact on endurance, but only when combined with exercise.

As with exercise, the two drugs trigger a rise in levels of mitochondria, the structures in charge of producing energy; a shift in metabolism that takes advantage of lipids as an energy source; and an increase in blood flow, which allows the steady delivery of fat to burn.

你是否曾经盼望过，只要吞下一粒药，你甚至不用踏上台阶机，就能取得酷似锻炼带来的所有积极效果？

霍华休斯医学研究中心(Howard Hughes Medical Institute)发现了两种药物，可以模仿在健身房锻炼后产生的许多生理反应，例如增强细胞燃烧脂肪的能力。

除了帮助抵御肌肉营养失调等肌萎缩疾病的影响外，这些药物还能预防肥胖和新陈代谢紊乱。

这些药物可以口服，它们的作用原理是对肌肉纤维进行基因重组，从而使肌肉纤维能更有效地使用能量，并能反复收缩，而不会产生疲劳。

根据《细胞》(Cell)杂志发表的实验室实验，在跑步机测试中，服用了药物的老鼠比普通老鼠跑得更快、更持久。譬如，服用了AICAR（两种药物的一种）的老鼠，比未服用的老鼠跑动时间长44%。

第二种药物GW1516对耐力的影响更神奇，但仅在与锻炼结合时有效。

和锻炼一样，两种药物都会导致线粒体水平提高，新陈代谢发生改变，血液流通速度加快。其中，线粒体结构负责能量的生成，新陈代谢利用脂质作为能源，而血液流通则保证了供燃烧的脂肪的稳定输送。