BodyPump and Personal Training - Changes in Muscle Strength and Body Composition
Condition: Overweight
MeSH terms: Overweight
Study type: Interventional

Summary: 
      This study is a four armed randomized controlled trial (RCT) where the main purpose is to
      investigate the effect on muscle strength and changes in body composition in overweight (BMI
      ˂ 25) "not regularly exercising" women aged 18-65, after 12 weeks of Body Pump (BP), compared
      with an inactive control group. The study will also measure energy expenditure during one
      session of BP. At the same time, the project will investigate the effect on muscle strength
      and changes in body composition in group training with, respective without, a personal
      trainer (PT).

      H0: There's no different between the groups after 12 weeks of Body Pump and traditional
      strength training with and without a personal trainer on muscle strength and muscle mass in
      adult overweight females.

      H1: There is a different between the groups after 12 weeks of Body Pump and traditional
      strength training with and without a personal trainer on muscle strength and muscle mass in
      adult overweight females.
    

Detailed description: 
      Background Regular physical activity confers protection against a number of both physical and
      mental health disorders (Hallal et al 2006; Bauman 2004). Physical activity also produces
      health benefits related to overall physical fitness and physical performance (Kruk 2007;
      Pedersen & Saltin 2006; Kesaniemi et al 2001). Physical activity can prevent cardiovascular
      diseases (Adedeji et al 2011, Anderssen & Hjermann 2000), type 2 diabetes (Admiraal et al
      2011), some types of cancer (Courneya & Friedenreich 2011, Friedenreich 2001) and mental
      illness e.g anxiety and depression (Harris et al 2006; Pedersen & Saltin 2006). Despite
      knowledge of benefits of regular physical activity, inactivity is a growing global problem
      (Kohl et al 2012).

      At the same time prevalence of overweight (BMI≤25) and obesity (BMI≤30) has doubled between
      1980 and 2008. In some regions, such as Europe and America, more than 50 % of women are
      overweight (Perèz Rodrigo 2013). About 35 % of the world's population over 20 years suffer
      from overweight, and 12 % are obese (WHO, 2008). In Norway around one in five adults has
      developed obesity (Ulset et al 2007).

      During the last two decades the fitness industry worldwide has increased considerably in both
      number of centers and number of members, and with this, there have been major changes in
      training opportunities (Bakken Ulseth 2003; Ommundsen & Aadland 2009). In 1987, 8 % of the
      adult Norwegian population reported to exercise at a fitness centre, compared with 25 % in
      2007 (Ommundsen and Aadland 2009). Today the fitness industry is the arena most women seek
      when they start physical activity (Vaage, 2004), but there is very little research about
      factors related to physical activity among those who choose to be physically active at
      fitness-centres.

      Resistance training has become a popular form of exercise for both women and men of all ages,
      and especially women do more resistance training today than in the past (Breivik, 2010). The
      health benefits of resistance training are many. With proper dosage and regular exercise it
      can increase muscle and connective tissue cross-sectional area and bone mineral density,
      improve functional capacity, reduce body fat, increase basal metabolic rate, decrease blood
      pressure, improve blood lipid values, glucose tolerance and insulin sensitivity (Kelley &
      Kelley 2000; Pollock et al 2000; Feigenbaum & Pollock 1999). These benefits, as well as
      performance-related benefits, can improve quality of life in different populations, such as
      those with overweight and obesity (Pollock et al 2000).

      The effect on muscle strength varies between studies, which may be attributed to factors such
      as study design, methods and genetics. Yet untrained people can generally expect an increase
      in 1RM (one repetition maximum) of 30-40 % after 12 weeks (Raastad et al 2010). Increase of
      muscle volume (hypertrophy) in untrained individuals seems to be best achieved at a load of
      60-80 % of 1 RM (6-15 repetitions). Increase in maximum strength for untrained is located at
      70-85 % of 1 RM (4-8 reps), while local endurance strength is at 20-60 % of 1 RM (15
      repetitions or more) (Raastad et al 2010).

      Body Pump With increased activity in the fitness industry the provision of premade training
      sessions and concepts have increased accordingly. Within group-training classes, there are
      several different concepts with focus on muscle strength. Best known worldwide is Body Pump
      (BP) by Les Mills (www.lesmills.com). Les Mills International has been around since 1997 and
      is originally from New Zealand. Entrepreneur, Phillip Mills, developed a series of
      group-training classes with music, including BP. Today, over 14 000 fitness centers in the
      world offers group-training classes from Les Mills. In the Nordic countries 1039 centres
      offers BP, and 179 of these are in Norway (www.lesmills.com).

      BP intend to increase muscle strength and local muscular endurance, reduce fat mass (change
      body composition), as well as maintain or increase lean body mass (Les Mills International
      Limited 2007). The class contains 10 to 12 strength training exercises with barbell, weights
      and a step, and it is pre-choreographed for all instructors. Number of repetitions throughout
      the class varies between muscle groups, but is generally high. Les Mills certifies
      instructors and offer refresher courses four times a year. The fitness centers offering BP
      pays a monthly license and receive new programs four times a year. Les Mills advertises that
      BP is suitable for both women and men, that the training session will burn up to 600
      calories, increase muscle strength, improve public health, strengthen bones and give a sense
      of good wellbeing (www.lesmills.com).

      Currently few studies have examined the effect of BP or similar group-training classes on
      physical or mental health. Oliveria et al (2009) examined the effect on muscle activity
      during a single workout class with BP. They concluded that BP can improve muscle strength,
      but probably not affect cardiorespiratory factors. Internally published reports from the
      University of Auckland examined both the long-term effects of BP (Lythe et al 2000), as well
      as energy consumption during a single workout (Pfitzinger & Lythe 1999). Lythe et al
      recruited inactive women and men (n = 40), with an intervention period of 13 weeks of
      training (2-4 sessions per week). The results showed a significant reduction in skinfold
      thickness measured with caliper, when no other exercise or dietary changes were made. They
      also found an increase in muscle strength (6 RM bench press and legpress) and positive effect
      on psychological factors such as self-esteem and self-image. This study had no control group
      (Lythe et al 2000). Another internal report examined energy consumption during one session,
      and found that calorie consumption on average were 483 calories for men and 338 calories for
      women (Pfitzinger & Lythe 1999). The subjects in this study had experience with regular BP
      for three months ahead of the polls.

      Greco et al (2011) conducted a RCT in which they examined both muscle strength and changes in
      endurance after 12 weeks of BP on 19 untrained women (2 sessions per week). The results
      showed no changes in either endurance or body composition. However, they found significant
      changes in maximal muscle strength in the lower body and muscular endurance (Greco et al
      2011).

      Personal Trainer A relatively new profession, emerged in the past 20 years both in Norway and
      internationally, is the Personal Trainer (PT). PT's produces training program to their
      clients, and follow them over longer periods. They also instruct proper execution and
      technique, correct the training, control the intensity and serve as motivators (Ratamess et
      al 2008). The title "personal trainer" is not protected, and the exact number of PT's in
      Norway is unknown. Besides PT, most fitness centers offer a training manual with one hour
      instruction, included in the membership. They also offer one hour follow up with individual
      coaching after some weeks, but the members carry out the training on their own (www.sats.no).

      To our knowledge only one RCT has examined the impact of training with a PT (Mazetti et al
      2000). During a 12-week training program they found that the participants managed to train
      with heavier weights with a PT, compared with a group without a personal trainer. The group
      with PT also showed greater improvements in muscle strengths and greater increase in 1 RM. In
      addition the study found that those exercising with a PT subsequently choose heavier loads
      than those without a PT. A cross-sectional study found that customers chose heavier loads and
      had greater strength gains after a training period with PT, compared with a group without a
      PT (Ratamess et al 2008).

      To date, little is known about the effect of BP, despite the large number of participants who
      perform this group-training session daily. There are also many unanswered questions regarding
      the effect of exercising with a PT, and if there is any differences in efficacy between
      exercising in groups, with a PT or alone. The questions related to this field are important
      in relation to a general public health perspective, as well as the time and finances
      customers put into the concept.

      This study is a well-designed RCT, where the main purpose is to investigate the effect of
      regular muscle strength and changes in body composition in overweight (BMI ˂ 25) "not
      regularly exercising" women aged 18-65 years, after 12 weeks of BP, compared with an inactive
      control group. The study is four armed and will also measure energy expenditure during one
      session of BP. At the same time, the project will investigate the effect in muscle strength
      and changes in body composition in group training with, respective without, a PT.

      Articles

        -  The effect of 12 weeks of Body Pump and traditional strength training with and without a
           personal trainer on muscle strength and muscle mass in adult overweight females. A
           randomized controlled trial.

        -  Energy consumption during and after one exercise session of Body Pump in adult
           overweight women.

        -  The effect of 12 weeks of Body Pump and traditional strength training with and without a
           personal trainer on blood cholesterol, triglycerides and glucose in overweight adult
           females. A randomized controlled trial.

        -  Muscle Pain and Injuries in adult overweight females during 12 weeks of Body Pump and
           traditional strength training with and without a personal trainer.

      Method

      Participants The study recruited "not regularly exercising" women aged 18-65, with a BMI ≥
      25.0. "Not regular exercising" is defined in this study as "not regularly exercise more than
      one hour each 14th day" (Ommundsen & Aadland 2009). Recruitment took place via various social
      media channels, like facebook and NIH's homepage.

      Power Calculations Power calculations are done in collaboration with Professor of Statistics,
      Ingar Holme, at NIH. The BP group will be compared with an inactive control, and group C
      (resistance training with instructor) will be compared with group B (PT). With a standard
      deviation of 15 %, alpha = 5 %, and a statistical power of 80 %, we will need to recruit 30
      subjects in each group to detect a difference of 11 % in muscle strength (effect size: 0.73).
      We expect a loss of participants between 10-20 % throughout the study period. Hence, we will
      recruit 36 women to each group and a total of 144 participants (Greco et al 2011).

      Training According to the BP product manual it is recommended to exercise this concept 2-3
      times a week (www.lesmill.com). This is in accordance with the recommendations of resistance
      training from Health and Social Services Agency for inactive people, 2-3 times weekly (SEF,
      2000). In a BP session the exercises are squats, deadlift, bench press, standing forward
      rowing, french press, biceps curl, shoulder press and abdominal crunches. These exercises
      will form the basis for the development of the training program in group B and C as well. All
      participants used a training diary for adherence.
    

Intervention name(s): BodyPump; Personal training; Resistance training with instructor
Intervention type(s): Other; Other; Other
Intervention description(s): Participants will be offered BP sessions at fitness centers in Oslo/Akershus. They will exercise three times a week. The instructors at all centers have a BP license from Les Mills, and the same program will be conducted at all centers at all times. The project manager has been in contact with Les Mills Scandinavia and has been given permission to use the training concept for research.; Participants in this group will be offered training with a PT at the Norwegian School of Sports Sciences. They will exercise with their PT three times per week. The training program for this group will be based on the exercises in the BP class, but repetitions will vary between 3-15, and series between 2-4.; Participants in this group will be invited to train on their own, three times a week, at the Norwegian School of Sports Science. Prior to the intervention period they will receive a training manual, instructions of the exercises and advice about progression during the intervention period. They will also have a follow-up with the same instructor after six weeks. The training program for this group will be the same as for group B. The PT's from group B will also serve as training instructors.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Muscle strength; Body composition; Body weight; Resistance training; Personal training; BodyPump