I truly feel blessed today. God granted me the energy for VCS singing time. I was worried about it. My fingers are sore, and yesterday I was having trouble making the chords to make my guitar sound good, but today I was able to do it. And no back pain or hip pain either!
So, God sustains us. We should remember that. Not just in extraordinary circumstances, but every minute of every day. He keeps us alive and no matter what, we depend on Him.
I think if you've been blessed with lots of energy, you should give thanks to God for it, and if you are ill, you should do what God commands, and "Be still and know that I am God."
Either way, it's a blessing.