Resistance and Aerobic Training, Relationship With Birth Weight in Colombian Children
Condition: Resistance Training; Cardiovascular Risk; Low Birth Weight
MeSH terms: Body Weight; Birth Weight
Study type: Interventional

Summary: 
      Background Risk factors for cardiometabolic diseases have their onset in infancy.
      Comorbidities such as overweight, abdominal obesity, hypertension, insulin resistance and
      elevated triglycerides have been observed in childhood with a tendency to persist into adult
      life. Furthermore, this situation has generated an increase in morbidity and mortality rates
      due to chronic non-communicable diseases. One approach to decrease the impact of
      cardiometabolic diseases is the intervention with exercise training (strength and aerobic
      capacity), where an important role of protein intake plays a role in influencing the
      performance of strength training, due to the greater utilization of low-energy protein
      compared to aerobic exercise. In children, a better tolerance was reported in muscle strength
      exercises, with at least one supervised training session per week with moderate intensity (20
      minutes of physical activity). Currently, there is no consensus on the minimum time required
      to intervene and achieve significant changes in the metabolic profile of adolescents and
      children.

      Objective To evaluate the relationship between weight at birth and adaptations to aerobic
      exercise and muscular strength, and its effects on metabolic risk, body composition and
      physical capacity.

      Methodology An experimental study with individual analysis per participant would be perform.
      The sample will include a 12 to 17-year-old adolescent population. It will consist of two
      phases. The intervention will be based on moderate strength, power and resistance training
      programs, and/or moderate aerobic capacity exercise in circuit steps. The workouts will be
      done two times a week, approximately 30 to 40 minutes including warm-up, stretching and
      cooling. All participants personal and family history data would be collected and blood
      samples would be taken.

      Potential results Within the expected results, the protocol wants to implement a new
      methodology of physical capacity training. Furthermore, the protocol will evaluate if related
      cardiometabolic risk factors with the intervention would improve in target patients at risk
      of developing cardiometabolic diseases to identify them and prevent the occurrence of these
      pathologies in adult life.
    

Detailed description: 
      Type of study: Experimental study with individual analysis. Population object and sample:
      Adolescents from 12 to 17 years old of high school located in Bucaramanga's metropolitan
      area. The sample size was calculated to evaluate the difference between the maximum oxygen
      consumption (VO2max) between the control group and 20% of the intervention groups using an
      ANCOVA method, with a correlation of 0.5 between the initial and final evaluations. An error
      alpha of 0.05 and power of 0.8, obtaining a sample of 60 adolescents for each group.

      Description of the physical intervention or program: This is a strength, power and endurance
      training program of moderate intensity combined with aerobic capacity training Moderate in
      the form of circuit. The trainings will be performed twice a week between 30-60 minutes of
      training, 1 hour including heating, stretching, explanations and cooling.

      Baseline assessment: All adolescents will be provided with a CRF for past medical history and
      family history, a review of systems and physical examination. In addition, the following
      evaluation protocol is established: Health related physical fitness measurement (AFRS):
      Aerobic capacity, maximal strength, 6RM submaximal strength test, strength, power, muscular
      endurance and flexibility; Anthropometric measurements and body composition; Complete Blood
      Count (CBC), and Lipid Profile. Measurements with AFRS will be taken at baseline, after 3
      months of the program and at the end (6 months).

      Aerobic capacity: To measure the aerobic capacity, 20 Meter Shuttle Run Test will be applied.
      A site would be selected for the test, preferably a space of 25 meter or longer. It would
      need 4 cones, tape measure, compact disc (CD) with the test protocol and a CD player. The two
      ends of the 20-meter track should be clearly marked. For the execution, the adolescent will
      move from one line to another located 20 meters away and making the change of direction to
      the rhythm that is indicated by a sound signal that will progressively accelerate. The
      initial velocity of the signal would be 8.5 km/hr, and will increase by 0.5 km/hr/min (1
      minute is equal to one shuttle). The test will end when the adolescent is not able to arrive
      for the second time in a row to the start line with the audio signal. Otherwise, the test
      will end when the teen stops because of fatigue. The participant would start running when the
      CD player emits the sound. The participant will touch the line at the end of the track with
      the feet, turn abruptly and run in the opposite direction. At first the speed will be low,
      but it will increase slowly and steadily every minute. The participant will stop when they no
      longer can keep the pace set. Or if they feel unable to complete the one-minute period. It is
      important to remember the last number announced by the CD player when the participant stops,
      because this will be the participant's score. This test would be performed only once. When
      the schoolchildren finish the test or cannot keep the pace, the last completed palier would
      be recorded.

      Maximum isometric force: Hand dynamometry is an important test for assessing the physical
      performance and nutritional status of the participants and allows reference to the isometric
      muscular strength of the hand. The improve in muscle strengths are inversely associated with
      changes in total adiposity in childhood and adolescence. This test requires an adjustable
      dynamometer (TKK 5101 Grip D; Takey, Tokyo Japan) and a Right- and left-Hand Grip Rule. The
      Adolescent will tighten the dynamometer gradually and continuously for less than 2 seconds,
      performing the test twice (alternately with both hands) with the optimal grip adjustment
      according to the size of the hand (previously calculated with the hand grip rule). Allowing a
      short break between measurements for each measurement. The elbow should be in all its
      extension and the participant has to avoid the contact of the dynamometer with any part of
      the body. The Adolescent will take the dynamometer with one hand, try to apply the mayor
      strength possible. Would Squeeze gradually and continuously for less than 2 or 3 seconds. The
      examiner will show the correct form of execution. Adjust the grip measure according the size
      of the hand. The test will be done twice and the best result will be recorded. The maximum
      duration of the test will be 3-5 seconds, the size of the hand (right or left) should be
      measured to the maximum width. The accuracy of the measurement is 0.5 cm. During the test,
      the arm and hand holding the dynamometer do not touch the body. The instrument is held in
      line with the forearm. After a short break, a second attempt will be made.

      Power: Vertical Jump Test is a test that measures the length reached in the vertical jump and
      with the Lewis's formula can calculate the power of the Adolescent. In addition, the
      participants can measure the force of the jump with a Platform Kinetics. To use it, the
      adolescent must stand at a side of a wall, and bring the hand closer to the wall, keeping
      their feet on the platform. They would have to jump vertically as high as possible with both
      legs. The platform kinetics would record the best of the three attempts. The participant must
      put the hands by the hips, to isolate the muscles of the legs. And three attempts are made to
      allow the coordination of arm movements. The vertical jump test is performed against a
      movement, where there is flexion of the knees before the jump. The necessary equipment to
      carry out this activity is the force plate (PASCO, USA, software, NMP technologies, London,
      UK).

      Explosive force: The long jump test allows to measure muscle strength. For the test is needed
      a non-slip surface, a tape measure, tape and cones. The teenager is going to stand behind the
      jump line, they must stand with their feet in an equal distance to the anchor of their
      shoulders, parallel to the ground. Subsequently they will bend the knees with the arms in
      front of the body and from that position they will balance the arms, they will push with
      force and jump as far as possible. they will land on both feet simultaneously and in an
      upright position. The examiner will show the correct form of execution; the test will be done
      twice and the best result will be recorded. The horizontal lines of measurement are drawn in
      the drop landing zone at 10 cm, from 1 m from the take-off line. A tape measure is going to
      be put perpendicular to these lines. The examiner would be remained by the tape measure and
      will record the distance jumped by the adolescent. The jumped distance will be measured from
      the takeoff line to the back of the heel nearest to that line. A new attempt is allowed if
      the teenager falls backwards or contacts the surface with another part of the body.

      Strength of resistance: Using the same test and the high jump protocol, but the participants
      would have to jump repeatedly for 15 seconds. The test is implemented with a Platform that
      allows the evaluation of the time in flight, time of contact between jumps and the power in
      each jump. The resistance is calculated with the average of these variables for 15 seconds
      and a fatigue index.

      6-RM submaximal strength test: The American Academy of Pediatrics recommends strength
      training in the adolescent with a load adjusted to the ability of the Adolescent and with 6
      maximal repetitions (6RM), which means that loading in an exercise should allow adolescents
      achieve 6 concentric and eccentric movements with good technique. In the program use a range
      of loads (RM's) It is going to be lighter adjusted to the assessment of the beginning of the
      program, and after every 6 weeks of training, the protocol will implement the test of 6 RM in
      exercise in machines (chest press, folding, shoulder press, extension of the Leg) to adjust
      the load according to the progression of the strength of each adolescent.

      Flexibility: The protocol can define flexibility as the ability of the individual to get
      his/her body placed in as many positions as possible, both statics and moving positions. This
      implies a great capacity of mobility of the different corporal segments with an ample freedom
      of corporal movements.

      Weight: The adolescent would be placed in the center of the scale in a standard upright
      position, without the body being in contact with anything around him/her. The participant
      will remain in the described position on the previously calibrated weight balance and it
      would be determined the weight in Kilograms.

      Size: Have the participant stand erect on the floor board of the stadiometer with his or her
      back to the vertical backboard of the stadiometer. The weight of the participant is evenly
      distributed on both feet. The heels of the feet are placed together with both heels touching
      the base of the vertical board. Place the feet pointed slightly outward at a 60-degree angle.
      The adolescent will remain standing, keeping the position of Anthropometric attention with
      the heels, glutes, back and occipital region in contact with the vertical plane of the
      tallimeter. The evaluator makes an in-depth inspiration at the time of the measurement to
      compensate for the shortening of the intervertebral discs.

      Body mass index - BMI: The body mass index or the Quetelet index, has been defined as the
      ratio of weight to height squared (kilogram/m2). This index changes substantially with age,
      at birth, is as low as 13 kg/m2. The CDC proposes to use as cutoffs of the 85th and 95th
      percentile of its own data.

      Development of the study: There would be three arms of the study (strength group, aerobic
      exercise group and control group) of adolescents of 12 to 17 years old. The person
      responsible for the analyzes will be blind about the interventions. The analysis will be by
      intention to treat. Once the inclusion/exclusion criteria are checked, the selected
      candidates will receive information about the study objectives and methodology, and finally
      the adolescent will sign the informed consent and the guardian or responsible of the child
      will sign the informed consent too. After the screening procedures and the initial evaluation
      of the inclusion and selection criteria, the patients will begin the initial evaluation
      period. A balanced randomization will be carried out using random numbers generated in
      software systematized form, guaranteeing the homogeneity of the number of subjects in each
      arm, with internal random assignment with a ratio of 1:1:1 to receive the study intervention.
      This study is designed with a primary efficacy endpoint at six months and at twelve months.
      Upon completion of 6 months of intervention, the strength and aerobic capacity groups would
      be integrated into a single group to evaluate the combined effect of the interventions versus
      the control group.

      The study is divided into two phases carried out in several visits: Phase I is constituted by
      a visit -1 and 1, which includes the selection of the sample and the randomization. Phase II
      includes the execution of the study with three arms, one group will be assigned to strength
      training and the other to aerobic capacity training, taking into account the plan of sessions
      per week defined for SIMAC (three sessions). The control group will be monitored passively
      for the detection of adverse or secondary events. At the end of this phase, anthropometric,
      clinical and biochemical markers will be monitored in the two intervention groups and in the
      control group. In Phase III a combined program of strength and aerobic capacity will be
      implemented, which will last six months more than will be compared with the previously
      defined control group. Again, at the end of phase III, the outcomes related to possible
      changes in the anthropometric, clinical and biochemical markers in the two groups will be
      evaluated.
    

Intervention name(s): Muscular Resistance training; Cardiorespiratory training; Habitual training
Intervention type(s): Behavioral; Behavioral; Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The study is divided into two phases carried out in several visits: Phase I is constituted by a visit -1 and 1, which includes the selection of the sample and the randomization. Phase II includes the execution of the study with three arms, one group will be assigned to strength training and the other to aerobic capacity training, taking into account the plan of sessions per week defined for SIMAC (three sessions). The control group will be monitored passively for the detection of adverse or secondary events. At the end of this phase, anthropometric, clinical and biochemical markers will be monitored in the two intervention groups and in the control group. In Phase III a combined program of strength and aerobic capacity will be implemented, which will last six months more than will be compared with the previously defined control group.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Prevention