Catecholamine responses to high intensity cycle ergometer exercise: Body mass or body composition?

Concentration levels of selected hormones in judokas and the extent of their changes during a special performance test at different ambient temperatures

BACKGROUND

There is little scientific literature available on the diversity of physiological responses of judokas to anaerobic interval exercises in warm environments. Understanding the dynamics of changes in the concentration of selected hormones during a special endurance test at different ambient temperatures may have significant practical value, as it provides an opportunity for optimal programming and monitoring of the training process. So, the main aim of the research was to survey interval anaerobic exercises in different ambient temperatures on Concentration levels of selected hormones in judokas.

METHODS

15 judokas athletes (age: 20.65 ± 2.03 years; body height: 178.00 ± 6.31 cm;  body mass: 76.26 ± 12.57 kg; training experience: 12.1 ± 1.57 years) volunteered for the study. The judokas performed five sequences (each lasting 7.20 min) of pulsatile exercises on a cycle ergometer and hand ergometer in a thermoclimatic chamber at temperatures of 21 ± 0.5 °C and 31 ± 0.5 °C. The exercises were different from typical interval exercises, with varying times, upper and lower limb loads, and were followed by a 15-minute break after each sequence. Total duration of the experiment, including the five sequences of pulsating exercise and four 15-minute rest breaks between each exercise sequence, amounted to 96 min and 20 s. The workload was increased by 20 W for the lower limb tests and 12 W for the upper limb tests every 2 min. Biochemical measurements of testosterone (T), cortisol (C), growth hormone (HGH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), adrenaline (E), noradrenaline (NE), and β-endorphin (β-end)were performed using the enzyme-linked immunosorbent assay (ELISA) method on blood samples taken before and after five series of pulsatile exercises, at 1, 24, and 48 h.

RESULTS

Pulsatile exercise at ambient temperatures of 21 and 31 °C resulted in a decrease in body weight of the studied athletes (p < 0.05) and significantly reduced body volume and plasma volume after training (p < 0.05). The concentration of HGH, testosterone, cortisol and NE showed a statistically significant difference after the end of the series of pulsating exercises at both temperatures (p < 0.05) and did not significantly affect the concentration of ACTH, FSH and adrenaline concentration.

CONCLUSIONS

An increase in the concentration of growth hormone, cortisol and NE was observed after doing the work at both 21 and 31 °C ambient temperature. Physical exertion in both ambient temperatures contributed to a statistically significant decrease in testosterone concentration. Based on the obtained research results, it can be concluded that physical activity in various thermal conditions of the external environment activates the hormonal response to varying degrees, with the direction of changes depending on the external thermal factor.

Plasma volume response to 30-s cycle ergometry: influence on lipid and lipoprotein

PURPOSE

It has been suggested that exercise-induced changes in plasma volume (PV) confound the interpretation of biochemical data obtained during the recovery period from exercise. No studies have sought to assess the effect of short-duration, high-intensity exercise on PV change and plasma lipid and lipoprotein concentrations. The purpose of this study was to compare power profiles, changes in PV, and plasma lipid and lipoprotein concentrations immediately after and 24 h after exercise.

METHODS

Subjects undertook two 30-s, high-intensity cycle ergometer protocols after optimization of resistive loads calculated from total body mass (TBM) and fat-free mass (FFM). Power output indices were recorded and blood samples were analyzed before, immediately after, and 24 h after exercise.

RESULTS

Peak power outputs were significantly greater in FFM (1020+/-134 vs 953+/-114 W for FFM and TBM, respectively, P<0.05). No differences were found between TBM and FFM for mean power output, fatigue index, or work done. Significant decreases (P<0.05) in PV of 12.0+/-5.7 and 12.3+/-6.7% were recorded immediately after exercise for both TBM and FFM, respectively. At 24 h after exercise, a significant (P<0.05) increase in PV of 4.2+/-10.3% was recorded for TBM only. Significant increases (P<0.01) were recorded for serum triglyceride, cholesterol, HDL cholesterol, and LDL cholesterol immediately after exercise for both TBM and FFM. These increases disappeared when corrected for PV changes, with the exception of LDL cholesterol in TBM, which still displayed a significant increase compared with the preexercise values (2.50+/-0.74 mM (before) vs 2.72+/-0.84 mM (immediately after)).

CONCLUSIONS

Our data show that short-duration, high-intensity cycle ergometer exercise tests can induce significant plasma volume decreases in untrained subjects, which may affect the interpretation of bloodborne biochemical parameters.

Brief High-Intensity Exercise and Resistive Force Selection in Overweight and Obese Subjects: Body Mass or Body Composition?

The purpose of this study was to compare the maximal exercise performance of overweight and obese subjects during friction braked cycle ergometry of 10 s duration when resistive forces reflected total-body mass (TBM) or fat-free mass (FFM). Subjects were assigned at random to either protocol. Eleven healthy male university students (age 22.3 +/- 2 yrs, body fat 27.1 +/- 2%) participated in the study. Differences (P < 0.01) in peak power output (PPO) were found between TBM and FFM (1029 +/- 98 W TBM vs. 1397 +/- 146 W FFM). The findings of this study suggest that greater peak power outputs are obtainable when resistive forces reflect FFM as opposed to TBM. The results have implications that relate to the pathology of disease, related clinical examinations, and exercise prescription.