Arnold, if you want to build mass you need to lift heavy weight and eat everything in sight - eat every 2 hours, and top it up with Cyclone or such products which will combine both creatine to maintain your energy levels and whey protein for muscle repair. Working out in the hotel room just wont cut it as you need to be lifting weight you can manage no more that 6 - 8 reps per set. I suspect you'll need to start with gym weights machines to build your stabilising muscles first - you wont see big gains from these but you need them before going on to free weights. You should be able to complete a full body work out in 45 minutes to 1 hour, allowing only 1 - 2 minutes of rest between sets. Get to a gym 3 times a week and eat protein rich foods every 2 or 3 hours, plus a protein shake after your workout. You will not build mass with anything less, so it's up to you to commit to it, and if that means paying to use a gym then you pay for the gains. Don't waste money on bullworkers or other such gimmick devices. There is only 1 way to mass and that is to lift heavy free weights and eat enough to fuel your muscular development.