When bench pressing you use your chest, shoulders, and triceps to raise the weight, but your glutes, hamstrings, upper back, and core also work to keep you stable. Using so many muscles means you burn more calories and get a bigger effect on your metabolism than you would with simple stretch exercises. Basing your routine around compound movement gives your workout a higher metabolic burn leading to greater loss of fat.
When lifting weights, your body produces extra hormones which help your body to burn fat more efficiently. The lactic acid produced when lifting weights close to the point of muscular failure also leads to increased production of fat-burning hormones.
Only a 5-minute session of Simple Chest pressing burns 37 calories if you weigh 150 pounds, that's without any extra cardio or making changes to your diet. You can also use Gyms, Home Training, or Workout Accessories to make deadlifts, push-ups, rows, squats, and lunges less hard to help you burn calories easily.
Arrange your workout in a series, moving from one to another without resting. This keeps you active and burning calories. And alternate strength workouts with cardio fitness to burn more calories.