Little result from popular strength training

Little result – that’s the conclusion reached after various types of strength training have been tested in research projects on obese women.

Anne Mette Rustaden has studied the results of different types of strength training, especially "Bodypump". Photo: Shutterstock

The women’s training programs included one of the world's most popular strength training ones – with mixed results.

This is what is being shown by a doctoral project from the Norwegian School of Sport Sciences (NIH). Anne Mette Rustaden, who is behind the project, emphasises that not everything is clear.

Strength training for the overweight

Rustaden has studied the effect of various types of strength training among obese women. They were tested in training with a personal trainer (PT), alone or in a “BodyPump”. The training concept Bodypump is one of the world’s most popular. It is suitable for people who want to become stronger in a hurry.

Rustaden has completed the study as her doctoral thesis at the Norwegian School of Sport Sciences (NIH), Oslo. The background to this was that international and national health authorities had included strength training, together with fitness training in their recommendations for individuals suffering from obesity,.

Bodypump = Lightweight

“We wanted to investigate what effects such training actually has on a risk group like the obese. We wanted to make it as realistic as possible, with a regular, broad base training program, as it actually is in the fitness centre industry”, says Anne Mette Rustaden.

If you seek out a fitness centre to get started with strength training, you can usually choose between strength training with a PT, individual strength training and strength training in group – such as Bodypump.
In Bodypump, you train with a lighter load than with traditional strength training, but do many more repetitions. In one 55-minute session typically 800-1000.

To measure the effect of the training, the women were measured for maximum muscle strength, muscular endurance (coping with many repetitions) and body composition.

Little result

  • The Bodypump group achieved neither greater muscular max strength, greater muscular endurance nor better body composition.
  • The PT group achieved increased muscular strength and muscular endurance. There was no change in body composition. But gained greater strength in the legs than those who trained individually.
  • Those who trained individually also achieved increased strength and muscular endurance, but their increase in leg strength was less than it was for the PT group.
  • While the company behind Bodypump, Les Mills, claims that it consumes 540 kcal per session, the study shows significantly lower energy consumption.

“Are Bodypumpers wasting their time?”

“We’re not able to say that. It’s not something I can safely conclude through this one study. There are several methodological weaknesses that may have affected the result.”

Rustaden believes that strength training with such light weights did not work for this particular group and that the result was minimal through training with such a small load.

“And: Unfortunately, we both had a high drop-out rate and many who dropped elements of the Bodypump training. That, in itself, is a point worth consideration, but we can’t draw a double line under the answer.”

“Would you recommend people to train with Bodypump?”

”Yes, I would, but primarily as a variation in another strength training program. It’s probably better to prioritise traditional strength training, but Bodypump can ‘spice up’ the training program. And if Bodypump is the only option for some, it’s a whole lot better than nothing at all.”

Anne Mette Rustaden portrett
Anne Mette Rustaden defended her thesis at NIH on Friday 30 November 2018.

Increased fat-burning when resting

Anne Mette Rustaden has also not examined how the participants have been eating. For example, if their appetites have increased, they may have eaten more – even if they were told not to. This may have affected their body compositions. At the same time, she did not want to give the participants more measurement tasks along the way; then the dropout rate might have increased even more.

“What we know is that fat-burning when resting increased equally for the PT and Bodypump participants who took part in such a test.

As for fat-burning during the actual training, the company behind the concept, Les Mills, states that an increased Bodypump burns 540 kcal. According to Rustaden’s tests, the correct figure is just over 300, a result that is somewhat more than other Bodypump tests.

“This means, in terms of calories, you might just as well spend the same amount of time going for a brisk walk.”


Les Mills: - Great health benefits

“Our research team has made several studies documenting that ‘BodyPump’ has a given rise to a number of health benefits, gains that the Norwegian study does not address”, Lena Holmberg points out. She is the director of marketing at Les Mills Nordic and has been given this article for review. She says they have not focused as much on calorie burning in general, but have shown that not all calories are burned equally, and, furthermore: That Bodypump increases skeletal strength.
They point out that actual calorie burning varies with age, weight, gender and exercise intensity.

The ability to burn calories, which Les Mills uses as a basis for its websites, is predicated on a study from Auckland in 1999 which had 10 participants.


How the study was carried out

  • 143 overweight women were randomly divided into four large groups of very closely equal size.
  • The women were 15-20 kg overweight and had body mass indices (BMIs) of 30+. So they were not morbidly obese. They should not have been actively training during the previous six months.
  • The groups undertook three different types of training: Group training with Bodypump, strength training with a personal trainer (PT) and individual strength training where they only received help in getting started from a PT. The fourth group was a control group; they were not to exercise, only be measured. The training would take place three times a week over a 12-week period.
  • The women were measured for maximum muscle strength, muscular endurance and body composition, i.e. their amount of body fat in relation to their weight.


This is "Bodypump"

  • BodyPump is a “whole-body” training concept using barbells, light weights and step-ups.
  • Unique to the program is that it makes use of light loads and many repetitions – typically 800-1000 in one session – as opposed to traditional strength training where heavier loads and fewer repetitions are employed.
  •  According to the advertisement, it is suitable for those who want to gain strength quickly – and ideally be slimmer and in good shape
  • In Norway, around 150 fitness centres offer the concept. Worldwide, around 5 million people use Bodypump every week.
  • The concept is owned and operated by the company, Les Mills