Myth 1. Stretch First- Recent studies indicate that pre-event stretching can actually impair performance in sports requiring explosive power, like jumping or sprinting. While flexibility training helps maintain a full range of motion around joints — for optimal results, stretch after your workout.
Myth 2: Don’t let your knees go past your toes while doing a squat or lunge - in everyday activities such as climbing stairs, the knee and torso naturally move forward slightly in parallel with each other for balance — and to propel the body forward and upward. Restricting this movement when performing squats and lunges increases hip stress and could increase the load on your lower back.( for more info, Knee Movement & Proper Form During Lunge Exercises)
Myth 3: To burn fat, exercise at a lower intensity - Forget the “fat-burning zone” — just get out there and move. Your body burns both fat and carbohydrate calories to meet the demands of exercise. The proportion of fat or carbohydrate burned in a given workout depends on exercise intensity and duration, but when it comes to weight control, the type of calories burned with exercise doesn’t really matter. If you burn more calories than you consume, you’ll lose weight. If you don’t, you won’t.
Myth 4: Strength training will make you gain weight - If you’re concerned about preventing weight gain, strength training is actually something you should be doing. On average, adults who don’t engage in any strength training exercises lose about 4-6 lbs. of muscle tissue per decade, silently chipping away at their resting metabolic rates. Unless caloric intake is also reduced, fat weight tends to increase. Alternately, regular strength training on the major muscle groups at least twice a week helps prevent loss of muscle tissue, and can even help to restore it.