I commute 4-5 miles each way - I wear regular shorts and tshirt in summer and change clothes in my office. In fall and winter I often just wear my work clothes (I teach) I keep a bar of soap and a washcloth and anti-perspirant at desk to rinse off with and reapply. I shower before riding in - keep pace slow to kee p from getting way sweaty. In the summer - in humid midwest - I get sweaty but this seems to work. I wear wicking underwear or I would change - cotton stays too wet. I keep shoes and belt at work - or I would forget them. I have a bike for commuting that I have a rack on - I hate to carry stuff on my back - even for a short ride. THere are also baskets that might fit over handlebars if you don't want a rack.