Ask any athlete. He'll tell you that! He's pushed his body to what can be called the maximum. His side and body has hurt. His lungs would have ached, and probably had cramps in his legs. And just when he felt like he couldn't go on, he's heard his coach saying, "Come on! Move it! Get going !!"
Athletes call that "hitting the wall." It's a time when the body says, "That's it. That's all I can do. I can't go any further. I can't go any faster. I quit."
I can do all things through Christ which strengthens me. - [Philippians 4:13]
But the seasoned athlete knows that "the wall" isn't the end. It's a signal that he's on the verge of a breakthrough. If he'll toughen up and push himself a little more, he'll get a second wind. Suddenly, he'll go faster than before. He'll reach a level of excellence he couldn't have reached any other way.