Hi Happy,
Don't take it as a personal comment. There are many people who work hard during Ramadan and I have 2 such friends I always admire. Now I can add one more to the list. But most people display this attitude and I am also generally told that nothing works in Ramadan etc. But I think it is agreeable that when we fast everyday for a month, we tend to become tired. It's only natural.

My take is, there is no need to glorify with scientific explanations etc. Just take it to heart, be devout, and chug along.