Exercise training elicits acute and adaptive long term changes in human physiology that mediate the improvement of performance and health state. The responses are integrative and orchestrated by several mechanisms, as gene expression. Gene expression is essential to construct the adaptation of the biological system to exercise training, since there are molecular processes mediating oxidative and non-oxidative metabolism, angiogenesis, cardiac and skeletal myofiber hypertrophy, and other processes that leads to a greater physiological status. Epigenetic is the field that studies about gene expression changes heritable by meiosis and mitosis, by changes in chromatin and DNA conformation, but not in DNA sequence, that studies the regulation on gene expression that is independent of genotype. The field approaches mechanisms of DNA and chromatin conformational changes that inhibit or increase gene expression and determine tissue specific pattern. The three major studied epigenetic mechanisms are DNA methylation, Histone modification, and regulation of noncoding RNA-associated genes. This review elucidates these mechanisms, focusing on the relationship between them and their relationship with exercise training, physical performance and the enhancement of health status. On this chapter, we clarified the relationship of epigenetic modulations and their intimal relationship with acute and chronic effect of exercise training, concentrating our effort on skeletal muscle, heart and vascular responses, that are the most responsive systems against to exercise training and play crucial role on physical performance and improvement of health state.

BackgroundRegulation of intracellular calcium (Ca2+) in cardiomyocytes is altered by hypertension; and aerobic exercise brings benefits to hypertensive individuals.Objective To verify the effects of aerobic exercise training on contractility and intracellular calcium (Ca2+) transients of cardiomyocytes and on the expression of microRNA 214 (miR-214) in the left ventricle of spontaneously hypertensive rats (SHR).MethodsSHR and normotensive Wistar rats of 16 weeks were divided into 4 groups -sedentary hypertensive (SH); trained hypertensive (TH); sedentary normotensive (SN); and trained normotensive (TN). Animals of the TH and TN groups were subjected to treadmill running program, 5 days/week, 1 hour/day at 60-70% of maximum running velocity for 8 weeks. We adopted a p ≤ 0.05 as significance level for all comparisons.ResultsExercise training reduced systolic arterial pressure in hypertensive rats. In normotensive rats, exercise training reduced the time to 50% cell relaxation and the time to peak contraction and increased the time to 50% decay of the intracellular Ca2+ transients. In SHR, exercise increased the amplitude and reduced the time to 50% decay of Ca2+ transients. Exercise training increased the expression of miR-214 in hypertensive rats only.ConclusionThe aerobic training applied in this study increased the availability of intracellular Ca2+ and accelerated the sequestration of these ions in left ventricular myocytes of hypertensive rats, despite increased expression of miR-214 and maintenance of cell contractility.

Introduction: The interest in minimalist and barefoot running is growing continuously. However, there is no data on how many runners drop out during this process. Objective: To describe the adhesion and dropout rates of a six-month instructed training program based on barefoot and minimalist footwear running. Methods: Thirty-four recreational runners participated in the study: 20 runners started the race training barefoot, while 14 runners were involved in training with minimalist footwear. Adhesion to intervention programs was evaluated through training spreadsheets and recording attendance at training sessions, while dropouts were evaluated at the end of training. A questionnaire was sent to participants who dropped out of the training, to obtain information related on why they had abandoned it. Results: Considering all participants (n=34), 41.2% of the runners completed six months with reduced plantar protection; 70% of all dropouts occurred in barefoot training; the main reasons for leaving the training were injury/pain (40%) and lack of time/suitable place for training (40%); and the majority of dropouts (50%) occurred in the first month of training. Barefoot training (n=20) showed 70% dropouts, 57.1% of them due to lack of time/suitable place for training; and 71.4% of the dropouts occurred in the first month of the intervention. The training with minimalist footwear (n=14) had fewer dropouts (42.9%) than the barefoot training, all of them due to injury/pain; 50% of them occurred in the third month of intervention. Conclusion: Dropouts usually occur at the beginning of training. Training involving barefoot running has more dropouts than training with minimalist footwear. Intervention programs lasting six months based on minimalist footwear/barefoot seems to have similar adhesion to other supervised exercise programs. The main reasons for dropping out are injury/pain and lack of time/suitable place to run.

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