wait I was coming to the topic
so what you feel in the afternoon is called afernoon slump and more than 50% of population feels the same way
You have to understand there’s no way to avoid it completely but you can minimise it by following these steps;
Most important take good sleep at night. 8 hours or a little more is best if you want to be productive all day.
shift your workout to afternoon or late morning like I workout 11am-12 pm then take a cold shower which helps me stay alert even after lunch.
drink a lot of water whenever you feel sleepy in the day. gulp down a glass forcefully and you’ll feel much better
these are the main points @prothekter_aden