Many people who start resistance training want to increase their strength and improve their body composition by building muscle. Unfortunately, many of those people fail to achieve their goals. People fail to increase their strength or muscle mass for a variety of reasons, but one of the most common is not lifting heavy enough weights to trigger growth and adaptation.
In resistance training, the amount of weight used during a particular exercise correlates with intensity, and in sports science research and athletic training programs, intensity is often expressed as a percentage of 1-rep maximum (1RM). That’s the maximum amount of weight that can be lifted during a particular exercise, with good form, for only one repetition. Once 1RM has been determined, a percentage of that maximal weight is prescribed for each exercise in a session. For example, an athlete’s program might call for four sets of bench press at 80% of 1RM.
Some studies have found that resistance as low as 45% of 1RM can be beneficial for increasing strength in the early stages of training,1 but that level of resistance is unlikely to be effective after the first few weeks. To make meaningful, ongoing gains in strength and muscle size, beginners (people with little or no resistance training experience) should be lifting at least 60-70% of their 1RM. Experienced lifters (who have at least 6-12 months of weight training experience) should be lifting at least 70-80% of their 1RM.2
Lifters Go Too Light
A few research studies have tested whether the average person chooses weights that meet these guidelines for resistance training.
- Glass and Stanton3 had 13 men and 17 women with no resistance training experience choose their own resistance for five different exercises: bench press, leg press, seated row, shoulder press, and bicep curl. They were allowed to perform as many repetitions as they wanted, with the instruction that they should “choose a load that you feel will be suf?cient to improve your muscular strength”. The participants selected weights that were an average of 42-57% of their 1RM, and performed between 10 and 25 repetitions, depending on the exercise.
- Focht4 had 19 women with no resistance training experience choose their own resistance to perform 10 reps on the chest press, leg extension, lat pulldown, and shoulder press. Those participants selected weights that were an average of 56% of their 1RM.
The average participant in each of these studies chose resistance that was too light to make significant, ongoing improvements in strength or hypertrophy. These findings aren’t exactly surprising. The participants in these studies had no resistance training experience, and developing the ability to select appropriate resistance and to push yourself in the gym takes time and practice. I would hope that with some training experience and guidance, people would learn to select appropriate resistance for their goals. Unfortunately, two other studies indicate that that’s not necessarily the case.
- Ratamess et al.5 recruited 46 women who had been resistance training for at least three months. One group of these women had been training with a personal trainer for at least the previous three months, and the other group had been training on their own. The average length of time that the personal training participants had been working with a trainer was 15 months. The average total resistance training experience for the personal training group was 4 years, while the average total resistance training experience for the non-personal training group was 4.5 years. Each participant was asked to choose a resistance that they would normally use for 10 repetitions. Four exercises were tested, all of which were machine-based. They included the chest press, leg press, seated row, and leg extension. In the non-personal training group, average chosen resistance was 38-48% of 1RM, and in the personal training group, average resistance was 43-57% of 1RM, depending on the exercise.
- Dias et al.6 recruited 12 men and nine women with at least 12 months of resistance training experience. One group of participants had been training with a personal trainer for at least two days per week for the previous six months, and the other group had been training on their own for at least six months prior to the study. Each participant was instructed to choose a resistance that they would typically use in their own workout for 10 reps on the leg press, bench press, leg extension, and bicep curl. The non-personal training group selected resistance that was 42-61% of their 1RM, and the personal training group selected resistance that was 48-62% of their 1RM, depending on the exercise.
In both studies, participants expressed that their goals were to increase strength, hypertrophy, or “muscle tone,” but the average participant, regardless of whether they had been training with a personal trainer, didn’t select heavy enough resistance to achieve those goals, considering their training experience. The authors of both studies reported that their participants were “surprised” or “astonished” at how much weight they were able to lift during the 1RM tests, and that most of the participants had never trained at an intensity close to those values.
Trainers Help, But Some Fall Short
Both studies reported that personal training did confer benefits. The personal training participants’ 1RMs were greater (11-16% and 6-26% greater in the Ratamess and Dias studies, respectively), and they selected relatively heavier resistance, on average, than the non-personal training participants.
Still, these findings are disheartening. It is disappointing that some of these study participants had been working with a trainer for years, and yet were unable to select appropriate resistance to meet their goals, and even reported afterwards that they had never lifted weights close enough to their 1RM to prompt ongoing strength or muscle gains.
A trainer’s job is to help their clients get the results they want, to educate them on how to train effectively, and to provide support and motivation. While there are many incredible trainers out there doing a great job every day, these studies seem to show that some trainers don’t live up to those expectations.
Muscles Don’t Tone
There’s a lot of readily available misinformation about fitness, and some people seem determined to believe that misinformation and train in ways which may not be appropriate for their goals. Some people have a misunderstanding of resistance training and many, especially women, may be hesitant to lift heavy weights. If they aren’t interested in increasing strength or size, low-to-moderate resistance may be appropriate. But often, people don’t want to lift heavy weights, and yet they want to get stronger, increase muscle size, or get “toned.”
A quick note about “muscle toning.” It doesn’t exist. This myth has been plaguing fitness professionals for too long, and it’s time we dispel it once and for all. Muscles don’t get toned, they don’t get longer or leaner. They get bigger, smaller, or stay the same size. That’s it.
People, especially women, who want “toning” are often referring to a lean and muscular physique without excessive muscle mass. That look is achieved by increasing muscle size and decreasing bodyfat. You do that with heavy resistance training and high intensity cardio. Lifting heavy weights will give them the physique they want, while lifting weights that are too light will likely do nothing but waste their time.
It can be hard to convince people to train heavy when many magazines and popular fitness blogs are telling them that they can “tone” their triceps by doing kickbacks with a soup can. But that’s part of a fitness professional’s job, and it’s in our clients’ best interests to do so.
Get to Know Your Heavy
If your goal is to increase strength or build muscle, it’s important to find a trainer that will educate you about effective resistance training and encourage you to progress to heavy lifting. For lifters, it’s important to keep in mind that you will eventually have to lift heavy weights to increase strength or muscle.
Here’s the important point: heavy is relative. It’s not about the weight; it’s about the effort. Heavy means a resistance that is challenging for the individual on that particular exercise and in their chosen repetition range. Heavy for a competitive powerlifter and heavy for a 40-year-old woman who has been lifting for two months are two completely different things. For that woman, squatting an empty bar for eight reps may be heavy, and performing full-depth bodyweight squats for 12 reps may also be heavy. As long as she’s consistently challenging her muscles and increasing the resistance over time, she will get stronger.
It’s also important that people learn how to recognize what appropriate resistance feels like. A good way to do that is to incorporate ratings of perceived exertion (RPE) into your training. A simple 1-10 scale can be used to measure RPE. The use of RPE to choose resistance training intensity within sessions has gained popularity recently as a form of autoregulation, which is a great way to structure advanced training programs.
That use of RPE isn’t good for novice lifters, however, since they haven’t yet developed the ability to accurately interpret their level of effort.7 Instead of using RPE to adjust resistance on the fly, they should record their RPE after each set for comparison later, to get used to thinking about the weights they’re lifting and their level of effort. Over time, they will develop the important ability to recognize what heavy weight feels like, how heavy a weight is relative to their lifting ability, and how to regulate their own effort. That ability usually develops naturally with practice, but the process can be expedited using RPE.
Progress Slowly, But Keep Progressing
Incorporating gradual progressions is another essential aspect of promoting heavy resistance training. Building confidence and competency with relatively light weights or easy exercise variations and gradually increasing the resistance is a good way to alleviate new lifters’ concerns about heavy weights. Instruction in proper form from a quality trainer and the mental and physical safety net provided by a good spotter is also important in helping to build the confidence to start lifting heavier.
Trainers and lifters alike need to be aware of the common barriers to achieving results. If you are working to improve your fitness and reach aesthetic or performance goals, you aren’t going to get very far without lifting heavy.
1. Anderson, Tim, and Jay T. Kearney. “Effects of three resistance training programs on muscular strength and absolute and relative endurance.” Research Quarterly for Exercise and Sport 53, no. 1 (1982): 1-7.
2. Kraemer, William J., and Nicholas A. Ratamess. “Fundamentals of resistance training: progression and exercise prescription.” Medicine and science in sports and exercise 36, no. 4 (2004): 674-688.
3. Glass, Stephen C., and Douglas R. Stanton. “Self-selected resistance training intensity in novice weightlifters.” The Journal of Strength & Conditioning Research 18, no. 2 (2004): 324-327.
4. Focht, Brian C. “Perceived exertion and training load during self-selected and imposed-intensity resistance exercise in untrained women.” The Journal of Strength & Conditioning Research 21, no. 1 (2007): 183-187.
5. Ratamess, Nicholas A., Avery D. Faigenbaum, Jay R. Hoffman, and Jie Kang. “Self-selected resistance training intensity in healthy women: the influence of a personal trainer.” The Journal of Strength & Conditioning Research 22, no. 1 (2008): 103-111.
6. Dias, Marcelo RC, Roberto Simao, Francisco JF Saavedra, and Nicholas A. Ratamess. “The Influence of a Personal Trainer on Self-Selected Loading during Resistance Exercise.” The Journal of Strength & Conditioning Research (2016). DOI: 10.1519/JSC.000000000000166
7. Testa, Marc, Timothy D. Noakes, and FranÇois-Denis Desgorces. “Training state improves the relationship between rating of perceived exertion and relative exercise volume during resistance exercises.” The Journal of Strength & Conditioning Research 26, no. 11 (2012): 2990-2996.