Heart Rate Variability in Fibromyalgia - Effects of Strengthening Exercises

STUDY PROTOCOL: The experimental group (STRE) will receive strengthening training in "Station for lifting weight exercises" (Flex Mega 8, Flex Fitness Equipment Brand) using the recommendations of the American College of Sports Medicine (ACMS, 2010), twice a week, during 45 minutes for 16 weeks. The control group (FLEX) will receive stretching and flexibility exercise training according to the protocol of prescription and previously tested and described in appendix F (Valim et al., 2003), twice a week, during 45 minutes for 16 weeks. The minimum number of patients per group will be 30. The randomization will be by arriving order of the patients at the Clinic, having 2 groups with a distribution at random one by one. There will be an examiner for the selection and unblinded randomization and another for the application of tools that will be blind. Patients will undergo clinical and cardiological evaluation with an exercise stress test (Ergometric test) request in all of them according to ACMS as one more method of evaluation for inclusion and exclusion.

The evaluation will be performed by a blind examiner, an expert physiotherapist in rheumatology and trained for the application of the tools at the beginning, after 30, 60, 90, 120 days from the treatment onset.

The measure for prescription and muscle strength gain will be by the method of maximal repetitions (Lindh et al., 1994; Tritschler, 2003; Brosseau et al., 2008; ACSM, 2010). The evaluations will take place at the beginning, 30, 60, 90, 120 days (final evaluation). Evaluations will be performed by the same blind examiner for the examined group. The training team will be formed by a physiotherapist, physical educator, and experienced doctors at strengthening training and flexibility and stretching exercises and they must follow the following protocol.

PROTOCOL OF EXERCISES The strength training will be performed according to American College of Sports Medicine (ACSM) and will have a mild to moderate intensity representing 45% of the estimated 1RM obtained from the maximal repetition method. Eight major muscle groups will be trained (quadriceps femoris, hamstrings, biceps brachii, triceps brachii, pectoral, calf, deltoid, and latissimus dorsi) in 12 different exercises, with 3 sets of 12 repetitions (leg Press, leg extension, hip flexion, pectoral fly, triceps extension, shoulder flexion, leg curl, calf, pulldown, shoulder abduction, biceps flexion and shoulder extension). Theses 12 different exercises will be distributed in a composed circuit system of 2 sets of exercises: Set A ((leg Press, leg extension, hip flexion, pectoral fly, triceps extension, shoulder flexion) and set B (leg curl, calf, pulldown, shoulder abduction, biceps flexion and shoulder extension). Each set will be applied once a week alternatively. The exercises will be performed twice a week during 16 weeks.

During the training process a load increase will be performed in order to seek progressive muscle strengthening improvement in a controlled way and according to patients' clinical evolution. Blood pressure and heart rate will be monitored as well.

Strength and strengthening training will be performed at the Evaluation, Physical Conditioning and Rehabilitation Laboratory (LACORE) at the University Hospital in in Federal University of Espirito Santo.

We have chosen the frequency of twice a week because it is a frequency (for this kind of study) validated in the literature (Figueroa et al., 2008, Kingsley et al., 2009; 2010).