我在很多人的印象中，有些身材肥胖的人从来不做任何运动，却拥有超于常人的力气，这很让人感到疑惑。难道是天生神力吗？不太可能，因为这样的例子太多了。我想，我们不妨先来简单了解这个问题的对立问题，即人变瘦后力气也会跟着变小吗？
在大多数情况下，确实是这样的。就拿拳击运动员来说，赛前的急速减脂会造成绝对力量的下降。有研究指出，体重下降3%~6%时，肌肉（实验部位为大腿肌肉）的力量不会出现明显变化。当体重下降达到9%时，肌肉（大腿）的爆发力会出现显著下降。如果这个问题反过来，是否也会成立呢？
健身教练赛思为了鼓励学员努力减肥（减脂），用了4个月时间把自己吃成一个胖子，最终体重增加了47磅（约23kg）。从赛思的身材来看，他确实长胖了，但是他的力气是否真的也变大了？这个问题也让赛思感到好奇。
赛思拿来了以前训练用的哑铃（25磅），像以前那样做哑铃肩上推举。他清晰地记得，增肥之前他一共可以做10下。不过这次他只做了六七下就已经不行了。除此之外，赛思还记得自己在增肥前还能做出一个类似三点倒立的动作。
增肥后的赛思决定再次尝试这个动作，不过当时情况是这样的：Race Thought, the fitness instructor, was curious about whether his strength would increase along with his weight gain. He had gained 47 pounds (approximately 23 kilograms) over four months and wanted to test this hypothesis.
Thought recalled that before gaining weight, he could do ten repetitions of a shoulder press with a 25-pound dumbbell. However, after gaining weight, he could only manage six or seven repetitions. Additionally, Thought remembered being able to perform a similar inverted row before gaining weight.
To test this hypothesis further, Thought decided to attempt the inverted row again after gaining weight. His results were as follows:
Thought commented on his experience: "I feel like I've lost my athletic ability completely. Scientists say that the more you weigh, the more you can lift. But I feel like now I'm worse off than when I was heavier."
In reality, these physical changes are just superficial and do not reflect the underlying nature of the problem. "Increased strength" refers mainly to absolute strength increases rather than endurance and relative strength improvements.
For example, although Thought used the same weights for shoulder presses during his experiment but reduced in number due to increased body fat and lack of continuous training leading to some decline in muscle endurance and cardiovascular capabilities; it cannot be attributed solely to reduced strength.
Furthermore why couldn't race thought even attempt an upside down pose? This question is much simpler - when bodyweight increases due primarily fat (and water), flexibility will trend downwards towards deterioration as well as many obese individuals who cannot do pull-ups aren't because they don't have enough force - probably because they're too heavy for themselves!