Myth #1 Sit-ups and Crunches are great exercises for the abs.
The truth is your core is made up of more than just the rectus abdominis (the 6-pack muscles). Your core is made up of the transverse abdominis, external & internal obliques, the multifidus (small muscles in your deep back to stabilize the lumbar spine), erector spinae, and diaphragm! Crunches don't work all of your core muscles and can hurt you in the long run by putting strain on tight hips, low back, and neck muscles. Better options include: the Curl Up, Bird-dog, and Side Plank
Myth #2 The longer you can hold a plank, the better.
The truth is, professor and spine specialist Stuart McGill, PhD, teaches that to see results from planks, holding the position longer than 10 seconds is pointless: “There’s no utility to this kind of activity other than claiming a record,” he said. Instead, he believes plank benefits come from short, frequent holds, AKA the proven-effective method of interval training. He suggests multiple reps of 10-second planks to fire up your abs, glutes, and hamstrings.
Myth #3 Not feeling sore means you didn't get a good workout.
The truth is you can have a great workout and not be sore the next day. Proper recovery will help prevent achy muscles. To help minimize soreness, be sure to stay hydrated, get enough sleep, and replenish your body's nutrients like magnesium.
Myth #4 Strength training means using only heavy weights and machines.
The truth is you don't need only heavy heavy weights or gym equipment to increase strength. Alternatives would include bodyweight exercises, resistance bands, and medicine balls. Resistance band training promotes total-body activation, challenges your muscles, and helps you maintain pliability without excessive loading of your joints.
Myth #5 You need to give 100% to every workout.
The truth is you should stay present to keep good form, however, not every session should be the same level of intensity to avoid over-training. To give your body time to recover, it is recommended to have 2-3 intense sessions a week mixed with mobility work, pliability work, and cardio.