Do 30 - 40 minutes on the indoor bike, or spin bike, or elliptical machine, with the goal to achieve and maintain a Rate of Perceived Exertion (RPE) of 6 - 7.
See How to Calculate Your RPE for an overview of this heart-rate tracking methodology.
Lie on your back on a flat bench with a barbell on the rack over your upper body. The barbell should be at a level corresponding to the distance from your elbow to your hand when your elbows are bent at right angles at your sides. Take the barbell in your hands with your hands wider than shoulder-distance apart and your palms facing toward your feet. With the barbell still on the rack, contract your shoulder blades together and downward to raise your chest toward the bar. Engage your abdominals by pulling them in toward your spine to create a muscular "weight belt". You will use this technique to keep your back flat throughout the exercise—do not, at any time, permit your back to arch. Lift the bar off the rack and, keeping it steady, bend and lower your elbows to the side until they are at the level of your back. The bar should not touch or bounce off of your chest at any point. Keeping your head and neck in line with your spine and your back flat on the bench by engaging your abs, slowly press the bar directly toward the ceiling. Controlling the motion, return the bar to the position just above your chest, with your elbows at the level of your back.
Lie on your back on a flat bench with a dumbbell in each hand and your feet flat on the floor. Extend your arms straight up toward the ceiling, with your palms facing each other. Keeping your forearm, wrist, and the back of your hand in a straight line, lower both arms to the side. You will have a slight bend in your elbows as you do this. Keep your chest lifted and engaged. Lower until your elbows are level with your back, and then reverse direction, pressing the weights back up toward the ceiling, keeping your arms extended throughout, until your arms are again vertical.
Stand in a modified squat position, with your body bent at the knees and hips and your back flat. Your shoulders should be directly over your knees or only slightly in front them, and your upper body should be at an angle slightly less than 45 degrees. Hold a barbell in front of your body using an overhand grip, with your palms facing you and your hands shoulder-width apart. Lift the barbell up to your sternum by bringing your elbows back and your shoulder blades together for each rep. Keep your lower back and abs stable and engaged so that you maintain your back’s normal arch—make sure your back doesn't become rounded. At the top of your range of motion, your elbows will be behind you and your shoulder blades contracted. From this position, lower the barbell back to the starting position, keeping your back flat throughout.
Stand on the platform of a Gravitron machine, holding the parallel pull-up handgrips in each hand, with your palm facing inward in a neutral position. Step off of the platform and onto the foot rests, allowing your body weight to bring you down until your arms are fully extended. Quickly and powerfully pull yourself vertically upward while keeping your elbows close to your ribs, retracting your shoulder blades, and opening your chest. Try to keep your entire lower body (hips, knees, ankles) stable and still as you lift to ensure that you isolate your back muscles. At the top of your motion, your head should be above your hands, your chin level with the bars, and your neck in line with your spine. Your shoulder blades should remain retracted. Reverse motion and lower yourself with controlled speed back to the starting position while keeping the movement in the muscle; do not simply let go or allow your elbows to lock. Exhale on the flexion (the upward movement) and inhale on the extension (the downward movement). If you can manage a full set of these at the assigned number of repetitions, try adding a belt and a weight plate for an added challenge.
Holding dumbbells in both hands, stand with feet hip width apart. Bring the dumbbells to just above your shoulders, with your palms facing forward and your elbows bent down and to the side. Press both weights straight up from the shoulder toward the ceiling until your arms are extended and your elbows straight. Try to keep your shoulders down as you do this: no shrugging. Do not bring the weights around in an arc — they should not touch at the top of your lift; rather, push straight upward. From the top of your lift, bend your elbows and lower the dumbbells, again in a straight vertical line, to just above your shoulders.
Holding dumbbells in each hand with your palms facing in toward you, sit on a flat bench your feet together on the floor in front of you. Lean your upper body over your thighs, allowing the dumbbells to hang down on either side of your legs. Tilt the dumbbells at a slight angle so that your pinky will lead the hand in the outward movement. Your elbows should stay soft (slightly bent) throughout the exercise. From the starting position, simultaneously extend both arms up and out to the sides using the back of your shoulders to do work. Maintain the position of your arms as you lift and keep your traps relaxed throughout movement (do not shrug). Extend out until your arms are level with your back, and then reverse direction and slowly return to your starting position, maintaining flexion in your rear deltoids as you lower the dumbbells back down.