Many people choose to get their workout in by lifting weights, but lifting brings up the age-old question: Should I lift low reps and high weight, or high reps and low weight? The catch is, both ways of lifting are right. What really makes the difference is your end goal.
Not that you want an anatomy lesson, but here is a quick note to help understand what is going on.
Your muscle tissue is made up of two main muscle fibers: Type I and Type II fibers. Type I muscle fibers are slow-twitch muscle fibers. They are activated when the muscle is engaged and are slower to fatigue. Type II muscle fibers are fast-twitch fibers. They are activated when the force is too great for the slow-twitch fibers. These fibers fatigue quickly but have greater power, allowing them to pick up heavier loads.
If your goal is to lose weight, before I reveal which way of lifting is best, it is important to remember that muscle weighs more than fat. If you are eating healthy and lifting, you are most likely losing fat and gaining muscle, which is still a trip in the right direction. With that being said, with a goal of weight loss, it is important to perform high reps and low weight. Your reps should vary between 12-15 per set. Lifting lower weights will engage your slow-twitch fibers and will increase your muscle endurance. After a few weeks, you can start increasing your weight and lowering your reps.
Inversely, if you want to increase your muscle mass, it is most beneficial to lift heavy weights with low reps. It is even better for you if you mix up the workouts. For example, if you do high weight and low reps during your first week of training, try to perform mid low weight and high reps on the second week. If you keeping working the same workout style over and over, your body and mind will have gotten used to that single routine. This will cause your progress to plateau.
Another point that is really important is that going to the gym every possible moment to gain a lot of muscle is not always what is best for you. The high weight and low rep style can put a lot of stress and pressure on your joints, which requires you to take a longer recovery time.
Obviously, everyone’s body is personal to them and reacts to things differently. Have fun in the gym and find out what workouts are right for you.