Outside the office I swim 3 times a week for an hour fairly fast (for me) with no more than 5 minutes rest throughout. Otherwise I'm fairly lethargic the other

Outside the office I swim 3 times a week for an hour fairly fast (for me) with no more than 5 minutes rest throughout. Otherwise I'm fairly lethargic the other 4 days. In the office I make sure I get up and have a walk at least once an hour, either to get a drink, use the toilet or just have a wander round. It makes sure I don't spend too long slouching, dozing off and makes me take my eyes off the screen.