Stand holding medium-weight dumbbells at your sides, feet hip-width apart, core braced, knees slightly bent. This is the start. Hinge at your hips and push your butt backward, lowering your torso. Hinge until you feel a slight stretch in your hamstrings; focus on keeping your core braced as you do this. From this position, squeeze your shoulder blades and row the dumbbells to your ribcage. Pause, then lower the dumbbells and stand up, squeezing your glutes. That’s 1 rep. Do 3 sets.
While your body naturally produces vitamin D when you're under the sun, you're likely vitamin D deficient, especially if you have an office job or live in a region in which sunshine is a rare luxury. This deficiency affects overall health, and some studies suggest it may even hamper athletic performance and recovery from exercise. If you can't get enough vitamin D from the sun or from your diet, taking a supplement would be the next best thing.
Complete the exercises in each workout as Straight Sets. For example, you'll do one set of leg presses, rest for 30 seconds, do a second set, rest, do the third set. Then, move on to the next exercise. You'll complete all movements in both workouts this way. Complete 12 reps of all movements for 3 sets each, and rest for 30 seconds in between each set. Choose a weight load where the last two reps of every set are extra hard, where you wouldn't be able to do a 13th rep. You may find that you increase the weight load for each set while keeping the 12 reps for all three sets.