I had a similar problem a couple summers ago, I'm 5 10 and stay right at about 170 pounds. I was interning in spearman, Texas for an oil company and needed a way to keep my strength and muscle gains up. Without a weight room near by I used anything I had with me. I found great success using pushups to get upper body strength. One workout I did was pushups starting with 25 pushups while my feet were on a chair or bed, then without a break between 25 while feet were on the ground then 25 while my hands were on the chair. By the time your hands are on the chairs for the last part youll find your using all your strength to push yourself up. Doing that rotation about 4 times is the best strength workout I've ever done. Couple that with pullups on the chinup bar should help. use your dumbells to do squat jumps with the weight in your hand. get a jump rope that helps with quickness and explosiveness as well.
