I work a distance from home and find it difficult to commit to getting to the gym after work, which I'm trying to do because I want to build more muscle. I was thinking that a good, strong resistance band looped over my chair leg could let me work my biceps here in the office after hours, when most have gone home. This way I can do 30mins training and then go straight home. Can anybody tell me what I should look for in a good, strong resistance band? Or any known durable brands? I was gonna order some online. To give you an idea of resistance level I currently use a barbell to bicep curl 45kg, so I'm guessing something equivalent to 15-20kg would be good.
EDIT: To answer Moses' question, the problem with getting to the gym after work is the time of night I get there. Between the office and home there is often a lot of traffic, so I get to work early and I don't leave until late to avoid sitting in queues. So I usually leave at almost 7pm. Get to the gym at 8pm, do a workout for an hour, return home and cook, sleep... back up early to return to the office.
My thinking is that I can do some bicep curls or similar here in the office while I wait for the traffic to clear. It is not ideal and I'd rather be using the gym equipment, but it is not possible every night of the week.