I get asked this question a lot. Especially by those new to lifting. But, the data behind my responses will be valuable to anyone participating in a resistance training program. So let’s get into it- how much weight should i lift? Well, it depends…
For the sake of simplicity, we will split the general population into two groups. One, individuals whose main goal is muscle growth and hypertrophy. These would be the lifters whose main goal is training for “looks” or “aesthetics”. Two, individuals whose main goal is to develop strength/power and who care less about developing an aesthetic look. This post focuses on the first group.
We will begin with the concepts of “intensity” and “volume” with respect to a lifting session. These two variables go hand in hand, but a not synonymous with one another. Intensity can be described as the total energy output needed to perform a particular workout or set. Increasing volume within a particular workout will increase intensity, but if an individual is already working at their capacity with respect to intensity, we can add an additional day to their weekly training routine to increase total volume per week without increasing intensity. A study performed by wernbom and colleagues in 2007 looked at growth of the quads and biceps in individuals using varying rep ranges on each muscle group. For the quads, a rep range between the 40-60 per session yielded the most muscular growth, while 42-66 reps produced the greatest growth in the biceps. Note that this is the total amount of reps in an entire workout, not one set. These reps will be divided up into 1-3 exercises. From my experience, hitting the quads with two exercises, each with 3 sets of 10 reps would be optimal for those seeking hypertrophy. Now for the amount of weight needed. The key to promoting muscular growth is progressive overload. Meaning, we want to load the target muscle with more volume than it is accustomed to. Ideally we will stay in our optimal rep ranges, and add more weight to overload the muscle via volume. This will keep the intensity high, and create a catalyst for growth.
So now the natural question that arises is, should i lift until i fail? Or should i choose a weight that allows me to complete the optimal amount of sets and reps without hitting failure. Should you be lifting 60% of your one rep max? Or 80?
Well, this depends. For the most part, assuming your goal is hypertrophy (muscular growth as opposed to just strength) it comes down to your lifting experience.
A study done by sundstrup et al (2012) showed that electromyography (the recording of the electrical activity of muscle tissue,) was significantly less in the final reps of a failure set performed by an inexperienced lifter. In a study performed by drinkwater et al (2005) participants were athletes that had years of lifting experience. They were split into two groups, one group followed a non-failure routine, and one group followed a failure routine. Over time, the group that trained until failure showed greater fatigue , greater growth, and greater increases in strength (almost twice as much as the other group). So, for more experienced lifters, approaching failure is optimal in order to achieve muscular hypertrophy.
So, in a nutshell:
If you’re new (1 year or less lifting experience) and seeking muscular growth and development: utilize a rep range of 40-65 per muscle group. Do not hit failure. Focus on good form over heavier weights.
If you’re experienced (2 + years of lifting experience) and seeking muscular growth and development: utilize a rep range of 40-65 per muscle group. Work until failure (without sacrificing form). Incorporate drop sets, rest-pause sets, and forced reps (with a spotter) to break through plateaus.
Wernbom, m., augustsson, j., and thomee, r. (2007). The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans. Sports med. 37, 225–264. Doi: 10.2165/00007256-200737030-00004
Sundstrup, e., jakobsen, m. D., andersen, c. H., zebis, m. K., mortensen, o. S., and andersen, l. L. (2012). Muscle activation strategies during strength training with heavy loading vs. Repetitions to failure. J. Strength cond. Res. 26, 1897–1903. Doi: 10.1519/jsc.0b013e318239c38e
Drinkwater, e. J., lawton, t. W., lindsell, r. P., pyne, d. B., hunt, p. H., and mckenna, m. J. (2005). Training leading to repetition failure enhances bench press strength gains in elite junior athletes. J. Strength cond. Res. 19, 382–388. Doi: 10.1519/r-15224.1