Moderate-intensity exercise might be a competitive protocol to prevent obesity and obesity-related metabolic diseases

To determine effects of exercise intensity on expression levels of cytokines and neurotransmitters beneficial for the prevention and improvement of obesity and obesity-related metabolic diseases. Expression levels of irisin, fibroblast growth factor-21 (FGF21), adiponectin, free fatty acid (FFA), dopamine (DA), and serotonin (5-HT) levels after moderate-intensity (50% of maximal oxygen uptake (VO 2 max)) and high-intensity treadmill running (80% VO 2 max) for 30 min in 20 healthy men were compared. Blood samples were collected at three time points: before treadmill running (pre-EX), immediately after treadmill running (post-EX), and at 60 min after treadmill running (60 min post-EX). Expression levels of irisin, FGF21, adiponectin, FFA, DA, and 5-HT were increased after 30 min of treadmill running exercise regardless of exercise intensity. Their levels were increased at 60 min post-EX. They showed no significant difference immediately after exercise regardless of exercise intensity. Only irisin, FGF21, FFA, and DA levels showed significant differences between moderate-intensity (50% VO 2 max) group and high-intensity group (80% VO 2 max) at 60 min post-EX. Considering that FFA level at 80% VO 2 max was significantly lower than that at 50% VO 2 max during post-EX and side effects of high-intensity exercise, moderate-intensity exercise would be a more competitive method compared to high-intensity for the prevention and improvement of obesity and obesity-related metabolic diseases.

Anaerobic Capacity in Running: The Effect of Computational Method

IntroductionTo date, no study has compared anaerobic capacity (AnC) estimates computed with the maximal accumulated oxygen deficit (MAOD) method and the gross energy cost (GEC) method applied to treadmill running exercise.PurposeFour different models for estimating anaerobic energy supply during treadmill running exercise were compared.MethodsFifteen endurance-trained recreational athletes performed, after a 10-min warm-up, five 4-min stages at ∼55–80% of peak oxygen uptake, and a 4-min time trial (TT). Two linear speed-metabolic rate (MR) regression models were used to estimate the instantaneous required MR during the TT (MRTT_req), either including (5+YLIN) or excluding (5-YLIN) a measured Y-intercept. Also, the average GEC (GECAVG) based on all five submaximal stages, or the GEC based on the last submaximal stage (GECLAST), were used as models to estimate the instantaneous MRTT_req. The AnC was computed as the difference between the MRTT_req and the aerobic MR integrated over time.ResultsThe GEC remained constant at ∼4.39 ± 0.29 J⋅kg–1⋅m–1 across the five submaximal stages and the TT was performed at a speed of 4.7 ± 0.4 m⋅s–1. Compared with the 5-YLIN, GECAVG, and GECLAST models, the 5+YLIN model generated a MRTT_req that was ∼3.9% lower, with corresponding anaerobic capacities from the four models of 0.72 ± 0.20, 0.74 ± 0.16, 0.74 ± 0.15, and 0.54 ± 0.14 kJ⋅kg–1, respectively (F1.07,42 = 13.9, P = 0.002). The GEC values associated with the TT were 4.22 ± 0.27 and 4.37 ± 0.30 J⋅kg–1⋅m–1 for 5+YLIN and 5-YLIN, respectively (calculated from the regression equation), and 4.39 ± 0.28 and 4.38 ± 0.27 J⋅kg–1⋅m–1 for GECAVG and GECLAST, respectively (F1.08,42 = 14.6, P < 0.001). The absolute typical errors in AnC ranged between 0.03 and 0.16 kJ⋅kg–1 for the six pair-wise comparisons and the overall standard error of measurement (SEM) was 0.16 kJ⋅kg–1.ConclusionThese findings demonstrate a generally high disagreement in estimated anaerobic capacities between models and show that the inclusion of a measured Y-intercept in the linear regression (i.e., 5+YLIN) is likely to underestimate the MRTT_req and the GEC associated with the TT, and hence the AnC during maximal 4-min treadmill running.