A reminder that fasting goes along with power. The first Ramadan was performed while Muslims were engaged in the battle of Badr, where they were victorious.
This book (link below) talks about the relationship between power (strength) and fasting in a religious manner. It’s a short pdf worthwhile reading!
So fasting does not necessarily makes one weak. The mindset is the determining factor. If spirituality is strong, weakness will not be felt.
And don’t forget that fasting without praying doesn’t make much sense.