Less fatigue at a lower weight

This sounds like it is one of those things that might sound good in theory but isn’t actually the case but If someone has lost weight say, 4-5 kg, would their day to day strain be less considering their muscles don’t have to work as hard to move around if they’re not being strained as much as their is less weight and load being placed on them potentially leading to an athlete being able to train under a high load seeing as they are recovering better? If anyone with better knowledge than me could answer, TIA.