These results suggest that eccentric muscle training is more osteogenic than concentric muscle training and that eccentric training is more efficient by attaining higher force production with lower IEMG.

No abstract

BackgroundIndividuals with Substance Use Disorder (SUD) have lower baseline metabolic activity of the prefrontal cortex (PFC) associated with impairment of cognitive functions in decision-making and inhibitory control. Aerobic exercise has shown to improve PFC function and cognitive performance, however, its effects on SUD individuals remain unclear.PurposeTo verify the cognitive performance and oxygenation of the PFC during an incremental exercise in SUD individuals.MethodsFourteen individuals under SUD treatment performed a maximum graded exercise test on a cycle ergometer with continuous measurements of oxygen consumption, PFC oxygenation, and inhibitory control (Stroop test) every two minutes of exercise at different intensities. Fifteen non-SUD individuals performed the same protocol and were used as control group.ResultsExercise increased oxyhemoglobin (O2Hb) and total hemoglobin (tHb) by 9% and 7%, respectively. However, when compared to a non-SUD group, this increase was lower at high intensities (p<0.001), and the inhibitory cognitive control was lower at rest and during exercise (p<0.007). In addition, PFC hemodynamics during exercise was inversely correlated with inhibitory cognitive performance (reaction time) (r = -0.62, p = 0.001), and a lower craving perception for the specific abused substance (p = 0.0189) was reported immediately after exercise.ConclusionDespite SUD individuals having their PFC cerebral oxygenation increased during exercise, they presented lower cognition and oxygenation when compared to controls, especially at elevated intensities. These results may reinforce the role of exercise as an adjuvant treatment to improve PFC function and cognitive control in individuals with SUD.

IntroductionThe brain plays a key role in the perceptual regulation of exercise, yet neuroimaging techniques have only demonstrated superficial brain areas responses during exercise, and little is known about the modulation of the deeper brain areas at different intensities.Objectives/methodsUsing a specially designed functional MRI (fMRI) cycling ergometer, we have determined the sequence in which the cortical and subcortical brain regions are modulated at low and high ratings perceived exertion (RPE) during an incremental exercise protocol.ResultsAdditional to the activation of the classical motor control regions (motor, somatosensory, premotor and supplementary motor cortices and cerebellum), we found the activation of the regions associated with autonomic regulation (ie, insular cortex) (ie, positive blood-oxygen-level-dependent (BOLD) signal) during exercise. Also, we showed reduced activation (negative BOLD signal) of cognitive-related areas (prefrontal cortex), an effect that increased during exercise at a higher perceived intensity (RPE 13–17 on Borg Scale). The motor cortex remained active throughout the exercise protocol whereas the cerebellum was activated only at low intensity (RPE 6–12), not at high intensity (RPE 13–17).ConclusionsThese findings describe the sequence in which different brain areas become activated or deactivated during exercise of increasing intensity, including subcortical areas measured with fMRI analysis.