How Much Weight Should You Be Lifting?
For those of you not interested in details, here’s the short answer: You should always lift as much weight as you can for the number of repetitions targeted by an exercise. If you aren’t doing this, you’re only getting a fraction of your workout’s potential.
Because the independent variable isn’t weight, it’s reps. Trainers often say, “Failure is not an option,” meaning that if you never fail during a set, you never know how much weight you should be lifting. You shouldn’t fail on every set, but occasionally failure lets you know you’re pushing to your limit, which is the key to results, whether your goal is to lose or gain weight.
A good rule of thumb is to begin each set with enough weight to barely reach the low range of the targeted repetitions determined by your trainer (eight to 12 or so). When you can reach the highest rep at that weight, it’s time to add just enough that you’re back at the low number. Repeat this process for as long as you’re doing that workout.
Now let’s take a more detailed look at why this is important and how much it matters, whether your goal is to gain mass, lose weight, or just get strong or ripped.
Time and repetitions
Most weight training exercises target a certain number of repetitions for each set. This number might stay constant over the course of a workout or change depending on the exercise. Either way, a basic understanding of why this is being asked of you will help you get the most out of your workout program.
Time, not numbers, is the actual factor that matters. Repetitions are used as a substitute for time because it’s far easier to count than it is to look at a clock. Occasionally trainers will use time but, for the sake of most of our goals, repetitions work well enough.
As a general rule, strength gains are achieved in fewer reps (less time), while muscular endurance improvements are achieved via higher reps. In between is the sweet spot for hypertrophy, also known as muscle growth.
A very brief physiology lesson will help you understand how these three protocols train your body differently and explain why you constantly need to change the amount of weight you’re using to get the most out of each workout.
The Short Attention Span School of Weight Training Physiology
Hypertrophy is what most workouts target because it’s the quickest means of changing your ratio of muscle to fat. Whether your goal is to lose or gain weight, beginning your workout program focused on hypertrophy changes your metabolism, which is the main objective in body transformation. Once your metabolism gets moving, your diet and remaining exercise program will determine whether you gain or lose weight and how quickly that change occurs.
What this means is that even if your goal is to lose weight, you should push hypertrophy workouts as hard as you can. Never take it easy, especially using the (much too common) rationale that “I don’t want to gain too much muscle,” because adding muscle accelerates fat loss, which is where the saying “muscle burns fat” comes from.
Furthermore, gaining bulk is a very difficult thing to do. Some people, especially women, tend to overthink this issue. Most bodybuilders would sell their soul for a few additional inches of muscle mass, so nothing frustrates them more than when others suggest that it can happen by accident.
Bigger muscles aren’t necessarily stronger
Combining low reps (or little time) with very high force loads (weight or the equivalent) is how you make muscles strong. The larger your muscles, the more capacity for strength they have. To be strong for their size, however, they must be trained to be efficient, which is done by using eccentric (negative) forces, plyometric (explosive) forces, or very low reps done with very high weight.
Scientifically speaking, this style of training is called recruitment (aka power); more specifically it’s the recruitment of high-threshold muscle cell motor units. It’s somewhat dangerous and very taxing on the body, which can be hard to understand because you don’t get “pumped” the way you do during hypertrophy training. But using heavy weight forces adaptations to your nervous system, which requires careful planning in order to stay healthy.
It’s the realm of sprinters, powerlifters, and other explosive athletes and is almost never used for those trying to change body composition. This means you’ll rarely encounter this style of program unless you’re training for a “power sport” or doing CrossFit.
Alternately, muscular endurance—when sets last longer than a minute (generally over 15 repetitions)—targets something called the glycolytic energy system, where both glycogen and oxygen come into play. This isn’t efficient for muscle growth—though some will still occur—and instead trains more endurance-oriented pathways in the body. Training using high reps increases muscular endurance efficiency and limits muscle growth potential. For this reason, it’s not often used for body composition change, but is sometimes used in conjunction with hypertrophy sets in order to increase something called time under tension (more on this later).
As you might surmise, high-rep weight training is actually very effective at creating a “toned” or “ripped” look. The reason it isn’t often used is because it takes a lot of time and, for pure body composition change, it’s more time efficient to do hypertrophy work in circuits or in a program combined with cardio workouts than to focus on muscular endurance alone. Therefore, it’s mainly only used by those who perform sports and activities that last between one and three minutes in length.
Mixing up your repetitions
Earlier, I mentioned time under tension, a term that refers to the cumulative effect of weight training workouts. It basically refers to the ratio of time your muscles have spent contracted during a given workout. Keeping this number high, while still using heavy force loads (weight/resistance), is one of the keys to creating muscular hypertrophy.
In order to do this, endurance sets are often added to hypertrophy sets, usually performed first. Referred to as pre-fatiguing the muscles, it’s a good way to increase time under tension when there’s a lack of equipment, such as available weight, a common scenario at home and in crowded gyms.