May I say then to those who are now or will be facing deep trials: May the Lord bless you that you may continue to hang on. There is purpose in it all, and he has promised us that the severity of it all will not be greater than we can endure...
And finally this promise from the Master: “And again, be patient in tribulation until I come; and, behold, I come quickly, and my reward is with me, and they who have sought me early shall find rest to their souls. …” (D&C 54:10)
Elder Loren C. Dunn, "Hanging On", General Conference, April 1974

In the very midst of a trial, it's difficult to see the positive. It's difficult to see that there's a purpose in it somehow. It's difficult not to focus on the negative, on our own plight and how that plight affects our perceived way of life.
It seems that many of these daily thoughts focus on enduring. The fact is, that mortal life is chock full of trials and challenges. How else can we progress? When Adam and Eve were exiled, Heavenly Father said "by the sweat of thy brow". Why do we sweat? Sweat is necessary to regulate body temperature.
So, to me that scripture doesn't just mean literally sweating from hard work, although that is necessary. But, it also means to me, figurative sweat as things get hard. Your emotional, mental, and spiritual self needs to regulate temperature as things get intense. So sweat is a way we cope with stress.
Heavenly Father is telling us that if we want to grow, we need to sweat. As stresses weigh us down and concern us, even challenge us, "sweat of thy brow" can mean there will be stress, there will be difficult times, there will be challenges. That is the only way that we achieve our "bread", or our reward. It will not just be handed to us without the work, physical or otherwise.