1. Don't stretch like this before a workout.
2. Literally everyone should have a goal in mind when they exercise.
3. Don't crush yourself to the point of exhaustion every time you work out.
4. If you want to build muscle, do strength training before cardio.
5. To figure out how much weight you should be lifting, try to do 10 reps with perfect form.
6. Doing two different exercises back-to-back will help you get more done in the same amount of time.
A superset is when you do two sets of different exercises in a row without resting. While supersetting two moves that target the same muscle group (like two upper body moves) is a good way to focus in on one area, supersetting opposing muscle groups speeds up your total-body workout, says Roberts.
For instance, alternating a set of pushups with a set of squats is more efficient than doing three sets of pushups (resting in between) and then three sets of squats (and resting in between). Since you're switching between upper body and lower body, you'll get the same workout without having to rest as much.
7. And try to pick exercises that are actually multitaskers.
8. To activate your core muscles, pretend you're about to get punched in the stomach.
Your core muscles (the ones in your stomach and back) should be activated during pretty much every exercise. That's why you'll often hear trainers say things like "tighten your core!" or "belly button to spine!" That's kind of vague though, so one way to make sure you're doing it properly is to pretend you're bracing yourself for someone to punch you in the stomach, says Perkins.
Try it: You would tighten those ab muscles and pull your stomach up and in. This should help you actually engage your core in the correct position, instead of just sucking in.