Energetic Contributions Including Gender Differences and Metabolic Flexibility in the General Population and Athletes

Abstract

Metabolic flexibility includes the ability to perform fat and carbohydrate oxidation, as well as oxidative capacity, which is associated with mitochondrial function, energetic contributions, and physical health and performance. During a session of graded incremental exercise testing (GIET), we investigated metabolic flexibility, the contributions of three energy systems, and performances of individuals with different metabolic characteristics. Fifteen general population (GP; n = 15, male n = 7, female n = 8) and 15 national-level half-marathon and triathlon athletes (A; n = 15, male n = 7, female n = 8) participated in this study. During GIET, heart rate (HR), oxygen uptake (V˙O2mean and V˙CO2mean), metabolic equivalents (METs) in V˙O2mean, and blood glucose and lactate concentrations (La−) were measured. Furthermore, jogging/running speeds (S) at specific La−, fat and carbohydrate oxidations (FATox and CHOox), and energetic contributions (oxidative; WOxi, glycolytic; WGly, and phosphagen; WPCr) were calculated. The percentages of HRmax, relative V˙O2mean, V˙CO2mean, and METs in V˙O2mean were all lower in A than they were in GP. FATox values were lower in GP than in A, while CHOox and La− were higher in GP than in A. Negative correlations between La− and FATox were also observed in both groups. Contributions of WOxi, WGly, and WPCr were higher in GP than in A during GIET. Moreover, values of WGly, and WPCr were significantly lower and higher, respectively, in male GP than in female GP. Furthermore, S at specific La− were higher in A than in GP. It is suggested that an individualized low-intensity recovery exercise program be established, to achieve increased metabolic flexibility and oxidative capacity (aerobic base), such as public health improvements and a greater volume of higher exercise intensities; this is the type of exercise that elite athletes worldwide mostly perform during their training period and progression. This may prevent cardiac/metabolic diseases in GP.

Diagnostics of νLa.max and Glycolytic Energy Contribution Indicate Individual Characteristics of Anaerobic Glycolytic Energy Metabolism Contributing to Rowing Performance

“…Our calculation revealed a percentage of 11.5 ± 2.9% which corresponds with the data from Diry and colleagues [ 17 ]. The used method is established to determine the proportions of the energy metabolism towards exercise [ 33 , 37 , 49 , 50 , 51 , 52 , 53 ]. However, our study showed a higher phosphagen contribution (10.9%) than the results from Diry et al [ 17 ] (1.5%) because of the different methodological calculations of the phosphagen system.…”

“…However, our study showed a higher phosphagen contribution (10.9%) than the results from Diry et al [ 17 ] (1.5%) because of the different methodological calculations of the phosphagen system. The time constant of mono-exponential function using off O 2 kinetics, which indicates phosphocreatine (PCr) recovery (return to baseline PCr levels) after intense exercise, serves as a more precise method to consider the phosphagen contribution in our study [ 33 , 37 , 52 , 53 , 54 ].…”

Effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults

“…Our findings indicate that individualized low-intensity Pilates exercises may enhance aerobic endurance and energy recovery in adults. The tendency of a rightward shift of the exponential lactate curve can be indirectly explained by improved energetic recovery ability, including fat oxidation and ATP re-synthesis, along with aerobic endurance capacity in zones 1, 2, and 3 [ 12 , 13 , 25 , 31 ]. If low-intensity Pilates exercise is performed for more than 6-8 weeks, due to its low energy consumption, Pilates exercise would improve the mechanism of fat metabolism and mitochondrial function [ 12 , 13 , 25 , 31 ].…”

“…The tendency of a rightward shift of the exponential lactate curve can be indirectly explained by improved energetic recovery ability, including fat oxidation and ATP re-synthesis, along with aerobic endurance capacity in zones 1, 2, and 3 [ 12 , 13 , 25 , 31 ]. If low-intensity Pilates exercise is performed for more than 6-8 weeks, due to its low energy consumption, Pilates exercise would improve the mechanism of fat metabolism and mitochondrial function [ 12 , 13 , 25 , 31 ]. Future studies with larger sample sizes are required to investigate how individualized low-intensity mat Pilates is related to other metabolism-related indices such as triglyceride, HDL-cholesterol, and fasting plasma glucose.…”

“…The blood lactate concentration was analyzed using an enzymatic-amperometric sensor chip system (Biosen C-line, EKF diagnostics sales, GmbH, Barleben, Germany). The test was ceased when La − exceeded 4.0 mmol·L −1 after each exercise test in all participants [ 12 , 25 , 31 ]. Following the test, every participant went through the recovery stage for 5 min at the same speed as the first stage to check the tendency of individual decreased lactate concentrations ( Figure 1 ).…”