stl map clear erase:跑步为何瘦不下来？

有些人们一心想要减轻体重，开始了不辞辛苦的长跑。这是一个合理的假设—跑步燃烧大量的卡路里（平均每英里消耗100卡路里），因此你会想当然地以为跑步可以减重。

However, some new runners find that they don't lose weight or they lose a few pounds and then hit a weight loss wall. What's going on? There's no simple answer here because there could be a few things happening.

然而，一些跑步新手却发现他们连一磅肉都没减下来。这是怎么回事呢？其中也许有一些微妙的原因。

It could be you're eating more calories than you need. Even if you're running, if you aren't burning more calories than you're consuming, you're not going to see a difference on the scale. You may be hungrier than you were before you started running, and you're eating more calories than you realize. Try spreading out your calories throughout the day into 5 or 6 small meals so you don't get ravenous and overeat. And make sure you're snacking on healthy foods, like fruits and veggies, not junk food, which can trigger hunger.

你也许是摄入了超出身体所需的热量。哪怕是你在长跑，若你所燃烧的热量不如你所摄入的那样多，你是不会看到任何锻炼效果的。你的饥饿感会比刚起跑时更加强烈，从而失控地大吃大喝。不妨试着一天之中少吃多餐5到6次这样你就不会因馋虫作祟而胡吃海塞。你还要确保你吃的是水果蔬菜之类营养健康的小食品，而不是那些让你越吃越饿的垃圾食物。

You may also need to switch up your running routine a little because your body is not as challenged as when you first started running. If you always run the same distance and pace, try increasing the distance of at least one of your weekly runs and incorporating speed intervals in one run. You can start adding speed by warming up for a mile and then running at a faster pace (breathing heavy but still in control) for a minute and then recovering at an easy pace for a minute. Continue with this pattern for two miles. When that gets too easy, you could always increase the time of your speed intervals or do hill repeats instead.

你或许还需要给你的长跑运动量加点料，因为你的身体需要不断地挑战新的运动强度。若你总是保持同样的运动量和速度，不妨试着至少每周加一点距离和速度间隔。你可以先跑个加速度的一英里来热热身，再加速度跑个一分钟，然后再恢复到一个平缓的速度跑个一分钟。坚持这个过程跑完两英里。当你可以轻轻松松适应了这个运动强度以后，你可以一直保持着加速度的长跑运动。

Another explanation is that you're building more muscle mass, which is denser than fat. So while your weight stays the same, your body fat percentage has decreased and you're more toned than you were before. Try to pay attention to how you're feeling overall, and use measurements other than weight, such as inches lost or how your clothes fit, to mark your progress.

另一个原因是你练就了更多的肌肉，肌肉可比脂肪密集得多。因此随着你体重的保持，你身体的脂肪比例会逐渐减少，你也就会变得更加骨感。不妨转移一下你的注意力，不再纠结于体重指数，而改为从其他视角去衡量你的进展，比如看一看自己减了多少英寸，衣服的尺码是否合身。