Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12613000509763
Ethics application status
Approved
Date submitted
2/05/2013
Date registered
8/05/2013
Date last updated
9/05/2013
Type of registration
Retrospectively registered

Titles & IDs
Public title
Strength training increases spontaneous physical activity in boys – a randomized controlled study
Scientific title
Strength training increases spontaneous physical activity in children (age 10.14-14.11) – a randomized controlled study
Secondary ID [1] 282436 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
physical activity in children 289042 0
Condition category
Condition code
Public Health 289385 289385 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
randomized controlled study
54 school children (age 10.14-14.11) in Switzerland were randomly assigned to participate twice weekly at a guided strength training programme for 19 weeks. Spontaneous physical activity energy expenditure (PAEE; 3-axial accelerometry for 7 days), leg and arm strength and body composition (DEXA) were measured at baseline, after 19 weeks of training intervention and after three months of wash out. The intervention consisted of an individualised maximum strength training programme for the whole body. Seven basic multiple-joint exercises were performed as a circuit in groups of two: Leg press, lunges with short dumb-bell, low back on back-bank or on mat, waist diagonal on mat, rowing exercise with short dumb-bell, bench-press with long dumb-bell, over-head-press with long/short dumb-bell. After the children were introduced to their exercise programme and had mastered the proper technique, the training loads were individually adapted (muscle fatigue) once per week to optimise strength and power gains. The training took place during two of the three regular 45 minuts PE classes over a period of 19 weeks, with group size of 18 children administered by two exercise physiologists. To monitor adherence, all pupils had to protocol all exercises (time under load, repetitions, weigth).
Intervention code [1] 287080 0
Prevention
Intervention code [2] 287104 0
Lifestyle
Comparator / control treatment
randomized controlled study
48 school children (age 10.14-14.11) in Switzerland took PE-lessons twice weekly for 19 weeks. Spontaneous physical activity energy expenditure (PAEE; 3-axial accelerometry for 7 days), leg and arm strength and body composition (DEXA) were measured at baseline, after 19 weeks and after three months. Physical education classes were conducted by a physical education teacher acording to the grade specific curriculum which include all physical activities while respecting the physical and mental and social well-being and take 45 minuts each. One exercise physiologist is supervising a class with about 18 children. Session attendance was protocolled by the teacher.
Control group
Active

Outcomes
Primary outcome [1] 289491 0
In the intervention group, compared to the control group, PAEE increased by a 10% from baseline to end of training in boys (p = 0.019), but not in girls. Physical activity energy expenditure (PAEE) was objectively measured for 7 consecutive days by a body-fixed triaxial accelerometer (RT3, Stayhealthy, Monrovia, California) in all participants. The accelerometer was worn following the manufacturer’s instructions at all times, except during sleeping hours and when taking a bath or a shower. Measurements of physical activity energy expenditure were analysed by a single blinded examinator.
Timepoint [1] 289491 0
after 19 weeks of intervention.
Secondary outcome [1] 302605 0
Leg and arm strength were increased due to training intervention in both boys and girls. Maximum strength of leg extension (leg press) and arm muscles (breast press) were tested by 1 RM testing (RM = repetition maximum). After a short standardized warm-up the participant performed the test with the maximum possible resistance (weight). All performance tests were conducted by a single examiner (R.P.).
Timepoint [1] 302605 0
after 19 weeks intervention
Secondary outcome [2] 302686 0
Lean body mass (LBM) and fat mass (FM) were measured by dual energy X-ray absorptiometry (DEXA, Hologic Discovery Wi)
Boys: Age corrected LBM slightly increased in the intervention group from baseline to the end of training intervention, however when comparing the groups LBM was unchanged. Age corrected relative FM was unchanged across the study and between the groups.
Girls:Age corrected LBM was decreased in the intervention group at the end of the training period (ns) and increased in the control group (ns), the differences between the groups being significant (p=0.02). At the end of training intervention relative FM significantly increased in the intervention group compared to the control group (p=0.03).
Timepoint [2] 302686 0
19 weeks

Eligibility
Key inclusion criteria
healthy schoolchildren
Minimum age
9 Years
Maximum age
15 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Children with a BMI above or below '+/-' 2.5 SDS or on stimulant medication such as methylphenidate participated in the normal PE classes and were involved in the measurements, but were excluded from analysis.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
1.sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Closed envelopes one for each participant seperated for boys and girls were drawn alternating for the control group and for the intervention group.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
As a result of the intervention, we expect an increase in spontaneous activity of 10-15%. With 40 probands and a co-variance coefficient in the activity measurement of 8% (our own data), there is a probability of 90% that a significant difference (p = 0.05) can be measured between the groups.
Student’s t-test was used to test differences between groups and univariate relationships were assessed with Pearson correlation analysis. Multiple regression analysis was used to test associations independently from possible confounding factors.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/09/2008
Actual
2/09/2008
Date of last participant enrolment
Anticipated
12/09/2008
Actual
12/09/2008
Date of last data collection
Anticipated
Actual
Sample size
Target
112
Accrual to date
Final
Recruitment outside Australia
Country [1] 5059 0
Switzerland
State/province [1] 5059 0
Zuerich

Funding & Sponsors
Funding source category [1] 287212 0
Self funded/Unfunded
Name [1] 287212 0
Prof. Dr. med U. Eiholzer

PEZZ Center of Pediatric Endocrinology Zuerich
Country [1] 287212 0
Switzerland
Primary sponsor type
Individual
Name
Prof. Dr. med. Urs Eiholzer
Address
Center for Pediatric Endocrinology Zuerich (PEZZ)

Moehrlistr. 69
8006 Zuerich
switzerland
Country
Switzerland
Secondary sponsor category [1] 285970 0
Individual
Name [1] 285970 0
Dr. med Udo Meinhardt
Address [1] 285970 0
Center for Pediatric Endocrinology Zuerich (PEZZ)

Moehrlistr. 69
8006 Zuerich
switzerland
Country [1] 285970 0
Switzerland

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 289201 0
Ethikkommission Zuerich
Ethics committee address [1] 289201 0
Kantonale Ethikkommission Zuerich
Sonneggstrasse 12
8091 Zuerich
Ethics committee country [1] 289201 0
Switzerland
Date submitted for ethics approval [1] 289201 0
30/01/2008
Approval date [1] 289201 0
24/04/2008
Ethics approval number [1] 289201 0
749

Summary
Brief summary
During the last fifty years, lifestyles changed from being physically active to being predominantly sedentary and inactive. Today, the majority of girls and a large proportion of boys fail to meet the minimum target of 60 minutes of at least moderate intensity physical activity (PA) per day. Furthermore, PA declines as children get older. Recently we have shown in children with Prader-Willi-Syndrome (PWS), as well as in healthy junior ice hockey players, that individually targeted strength training induces increased spontaneous PA outside of training. The main objective of this randomised controlled intervention study was to assess whether participation in a structured individualised strength training programme 2 hours per week would increase spontaneous daily PA outside of training in normal school children. We could show that a targeted strength training programme during regular school PE lessons increases the daily amount of spontaneous PA behaviour in children before puberty and that the strength training programme was most efficient for the children with the lowest PA at the beginning. The declining physical activity among children could be reversed if more specifically targeted PE classes, for example including strength training, were to become an integral part of physical education.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 39758 0
Dr Udo Meinhardt
Address 39758 0
Center for Pediatric Endocrinology Zuerich
Moehrlistrasse 69
CH-8006 Zurich Switzerland
Country 39758 0
Switzerland
Phone 39758 0
+41 44 364 37 00
Fax 39758 0
+41 44 364 37 01
Email 39758 0
[email protected]
Contact person for public queries
Name 39759 0
Prof Urs Eiholzer
Address 39759 0
Center for Pediatric Endocrinology Zuerich
Moehrlistrasse 69
CH-8006 Zurich
Switzerland
Country 39759 0
Switzerland
Phone 39759 0
+41 44 364 37 00
Fax 39759 0
+41 44 364 37 01
Email 39759 0
[email protected]
Contact person for scientific queries
Name 39760 0
Prof Urs Eiholzer
Address 39760 0
Center for Pediatric Endocrinology Zuerich
Moehrlistrasse 69
CH-8006 Zurich
Switzerland
Country 39760 0
Switzerland
Phone 39760 0
+41 44 364 37 00
Fax 39760 0
+41 44 364 37 01
Email 39760 0
[email protected]

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No Supporting Document Provided



Results publications and other study-related documents

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