You’re never going to squeeze in that workout on your lunch break if you don’t plan accordingly. Just grabbing a pair of sneakers on the way out the door won’t cut it. You need to be prepared to work, change clothes, workout, change clothes again, and return to work, all without bringing a cloud of body odor and sweat back to your cubicle. Luckily, it doesn’t take much to pack the perfect gym bag. You just need to know exactly what to throw inside.Pro tips: Don't rely on your pre-coffee brain to pack everything. Load up your bag before bed and put it by the front door or in your car. And if time is your main issue with catching a midday sweat, try one of these 20-minute workouts to get you in and out quickly.