Tip: Are You Using the Right Weight to Grow?

Twenty-one men and women with at least a year of lifting experience were recruited. Subjects were split into two groups:

• Group 1: Those who'd trained with a personal trainer for at least two days a week for the last six months.
• Group 2: Those who trained alone.

The subjects underwent three testing sessions. In the first session, they did three sets of ten reps for the leg press, bench press, leg extension, and arm curl using whatever weight they thought they needed. The second and third testing sessions were comprised of 1RM and 10RM assessments for each exercise to determine reliability.

• The group that had been coached by a trainer self-selected significantly more weight in all four exercises (12.1 to 26.6% more weight) than the group that always trained themselves.
• 1RM was significantly greater in all exercises in the personal training group compared to the non-personal training group.
• 10RM was significantly greater in the personal training group compared to the non-personal training group in all exercises but the leg extension.
• RPE (rate of perceived exertion) was significantly greater in the personal training group compared to the non-personal training group.
• The average intensity for all the exercises was 54% of 1RM and 49.8% of 1RM for the personal training and non-personal training group respectively. This means both groups were still well under the recommended intensity for hypertrophy (size) training.

In a nutshell, these folks were asked to choose the weight they thought they needed to build muscle. Those who'd worked with a trainer chose heavier weight. Those who hadn't worked with a trainer went too light to make gains. BUT, neither group really went heavy enough for their goal.

If you're training by yourself it's crucial you have some idea of what your 1RM is for larger exercises (squat, bench, deadlift etc.) and what your 10RM is for assistance exercises (as you really shouldn't be testing your 1RM for tricep kickbacks). That way, you can objectively see if you're training at the right intensity for the rep range you're working in.

While the personal training group did have greater self-selected loads compared to the non-personal training group, the subjects still weren't lifting at the appropriate intensity for the number of reps they were performing. So although they were going harder, they still weren't going hard enough when lifting without a trainer.

A proper plan going into the gym can mitigate this by holding you accountable to the correct intensity and will keep you from self-selecting loads that are sub-optimal.

1. Dias MRC et al. Influence of a personal trainer on self-selected loading during resistance exercise. J Strength Cond Res. 2017 Jul;31(7):1925-1930. PubMed.