The Application of Microcurrent in Athletes
Condition: Training Group, Sensitivity
MeSH terms: Hypersensitivity
Study type: Interventional

Summary: 
      The aim of this investigation is to analyse the potential benefits of wearing a new
      commercially available microcurrent device combined with different exercise training
      modalities on exercise outcomes, body composition, recovery including muscle damage, general
      markers of health and immune function in athletes.
    

Detailed description: 
      The investigation involves two randomised, balanced, double-blind parallel group
      between-participants design, aimed to analyse the effects of combining microcurrent with
      resistance and endurance training. Participants, once considered eligible for the study will
      be familiarised with the respective exercises, as well as tested for baseline values.
      Thereafter participants will be randomly assigned to one of the following intervention groups
      (1) Microcurrent (MCR+RT) with resistance training (2) Microcurrent (MCR+END) with endurance
      training (3) Sham with resistance training (SH+RT) and (4) Sham with endurance training
      (SH+END). Participants will perform 3 supervised training sessions per week (24 total
      workouts). Participants will wear the microcurrent or sham devices during 3 hr after
      workouts. Each group will follow a 10-week resistance or endurance training intervention
      combined with one of the two specific treatments (MCR or SH). Measurements of body
      composition, muscle thickness, performance, salivary and blood markers as well as delayed
      onset of muscle soreness will be determined before and after each particular (resistance or
      endurance training) intervention.

      Participants It is anticipated that sixty participants, recruited from the Medway University
      Campus, will take part in the project. Inclusion criteria are: regularly trained male or
      female athletes, aged 18 to 45 years old, with at least 3 months of experience in resistance
      or endurance training, with no musculoskeletal injuries, metabolic conditions, or diseases or
      use of medications, smoking, and nutritional supplements known to affect physical
      performance, muscle damage or recovery processes (e.g., creatine, whey protein, and amino
      acids, vitamin or mineral supplementation, etc) within 6 weeks prior to the start of the
      study.

      After being informed of all risks and potential benefits involved, participants will sign a
      written informed participation consent form. Procedures will be in accordance with the
      Helsinki Declaration and will be approved by the Research Ethics Committee of the University
      of Greenwich.

      Intervention Resistance training groups

      Familiarization period:

      Participants will undertake 3 sessions of familiarization (1 week). To ensure a correct
      execution of the selected exercise a qualified strength and conditioning coach will control
      and assists participants. All participants will be instructed about the appropriate use of
      the Rate of Perceived Exertion OMNI-RES (0-10) scale to control the load and training
      intensity during each workout.

      The resistance-training program is designed to increase strength and muscle mass of all major
      muscle groups. Under the supervision of strength and conditioning coaches, preferable a MSc
      Strength and Conditioning student from the University of Greenwich. The program will be
      undertaken on three non-consecutive days per week, Training workout will be performed during
      the afternoon (between 3 pm and 6 pm) with at least 48 hours between sessions.

      The intervention period consists of a 8-week periodised resistance training programme divided
      into 3 blocks: First block (week 1 to week 3) using a moderate load intensity of around 70%
      1RM; Second block (week 4 to week 6) where the intensity increases to >75% to 80% 1RM and the
      third block (week 7 to week 8) where the highest loads (>80 to 85% 1RM) are implemented. The
      Rate of Perceive Exertion OMNI-RES (0-10) scale (RPE) will be used to appropriately select
      the loading zone for each particular exercise during the workouts (Naclerio et al., 2015a,
      Naclerio et al., 2011)

      Each workout session begins with individualized warm-up (5-minute warm-up stretches, followed
      by one set of eight repetitions of six resistance training exercises without any additional
      weight). Workouts will involve 3 sets of 8 to 10 RM (self maximal estimation) with
      approximately 2 min of rest of the following exercises:

        1. Parallel back squat

        2. Hang clean

        3. Alternate lunges with dumbbells

        4. Bench press

        5. Upright row

        6. Double leg dead lift

        7. Push Press

        8. Front shoulder press and

        9. Biceps curl.

      Each workout will last between 45 to 60 min.

      The load will be increased or decrease based on the self-perception of the participants. When
      a minimum of 8 Reps is no possible to complete the participants will rest for 15sec and
      complete the set. Additionally, the participants can decide to reduce the load for the next
      set. Conversely, when more than 10 reps can be performed, the participants will stop the set,
      increase the load and complete the 10RM set.

      Endurance training Participants will commit to follow a polarised triphasic
      endurance-training model. This model contains three intensity zones calculated as low
      intensity [≥ the first ventilatory threshold (VT1), ~ 70% HRmax]; moderate intensity [between
      VT1 and respiratory compensation point or ventilatory threshold 2 (VT2), >70 < 90% HRmax];
      and high intensity [>VT2, 90% HRmax] (Esteve-Lanao et al., 2007). Participants will train 4
      to 6 times per week with a total percentage distribution of 75 to 80% at low intensity; 10%
      at moderate intensity, and 15 to 10% at high intensity. Participants have to be completed the
      same time exposure to the MCR or SH device after the end of the intervention period.

      Microcurrent or shadow

      Both the microcurrent and sham devices will look exactly the same in terms of appearance,
      colour, size and weight. As the current transmitted from the microcurrent device is
      insufficient to stimulate sensory nerve fibres, this stimulus is imperceptible and together
      with the same appearance, participants nor strength and conditioning coaches or researchers
      involved in testing will be able to identify participants under the MCR or the SH treatment.
      Only one researcher not involved in the assessment and training supervision will know the
      participant allocation during the study.

      Microcurrent or sham devices will be codified and placed on the participants before each
      training session. The participants will remove the device 10 to 15 min after completing each
      training session and return it to the strength and conditioning coach.
    

Intervention name(s): Microcurrent
Intervention type(s): Device
Intervention description(s): Microcurrent based treatments have been proposed more than 30 years. The manufacturer initially should calibrate the microcurrent devices. There is no physical sensation associated with microcurrent based treatments as the strength of the current is not high enough to stimulate sensory nerve fibres. The application of electric fields and currents similar to those generated within the body can substantially change the cell structure and the metabolic behaviour of cells. For example, the application of microcurrent increases the number of organelles responsible for cellular activities; it increases concentrations of adenosine triphosphate (ATP) and amino acid transport; promotes protein synthesis; fastens regrowth of atrophied soleus muscle and would also activate hormone-sensitive lipase which can increase lipolysis from the internal and external adipose tissue. The microcurrent treatment with training would maximize exercise and recovery outcomes in athletes.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Double-blind randomise controlled trial
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Microcurrent; Exercise training; Hypertrophy; Muscle damage; Recovery; Performance