This study examined the short-term effects (post 6 h and 24 h) of two equated (70% of 1 repetition maximum (1-RM)) low volume resistance exercise protocols: (i) velocity-controlled (VC) and (ii) ...repetition to failure (RTF) on upper and lower body performance in competitive adolescent male basketball players. Following a randomized, counterbalanced design, ten participants (age: 16 ± 0.5 years) completed either VC or RTF separated by 72 h. VC consisted of 4 sets of 5 explosive repetitions (≥90% of the maximum velocity). RTF involved 2 sets of 10-RM (with no velocity control). Measurements of 20-m sprint, countermovement jump (CMJ) and medicine ball toss (MBT) were collected before (baseline), post 6 h and 24 h after either VC or RTF. Increases of CMJ post 6 h (VC, +6.7%; RTF, +2.4%) and MBT post 24 h (VC, +4.6%; RTF, +4.2%) were observed after both VC and RTF. Only VC potentiated CMJ after 24 h (+2.0 ± 2.3%). No other changes or differences between protocols were observed. Performing a low volume exercise protocol, either VC or RTF, induced similar potentiation effects on the vertical jump (post 6 h) and medicine ball toss (post 24 h) in adolescent basketball players. Only the VC protocol was still effective to potentiate CMJ performance after 24 h.
Purpose: The purpose of this study was to investigate the differences in metabolic responses between the track and the treadmill (1% inclination) running. The latter is recommended for use in ...laboratory settings to mimic outdoor running. Method: Seventeen male endurance athletes (mean 25.8, s = 3.8 years) performed 4-min running bouts on an indoor track and the treadmill. Results: At all speeds (11, 13, and 15 km·h
−1
) athletes showed better economy on the track running compared to the treadmill expressed as oxygen (7.9%, 5.2%, and 2.8%) and caloric (7.0%, 5.3%, and 2.6%) unit cost. Rating of perceived exertion was evaluated substantially higher at all speeds on the treadmill (F(1,16) = 31.45, p < .001, η
2
p
= .663) compared to running on the track. Participants presented lower heart rate (F(1,16) = 13.74, p = .002, η
2
p
= .462) on the track at the speed of 11 and 13 km·h
−1
compared to the treadmill, but not at 15 km·h
−1
(p = .021). Conclusions: We conclude that constant inclination (i.e.. 1%) during the treadmill test might not be suitable to reproduce comparable effort to running on the track; rather, there is an optimal treadmill inclination for different intensities to reproduce similar effort compared to the track running.
To test the influence of the accumulation of metabolites on exercise-induced hormone responses, plasma concentrations of cortisol, growth hormone (GH), insulin, testosterone, thyrotropin (TSH), free ...thyroxine (fT4) and triiodothyronine (T3) were compared during exercise performed under normal conditions (control) and under conditions of restricted blood flow of exercising leg muscles (ischaemia) in nine healthy young men. Blood supply was reduced by 15%-20% by the application of 50 mmHg external pressure over the exercising leg. During 45-min cycling exercise during ischaemia the increase in GH concentration was twice as large as under normal conditions. Despite the below-threshold exercise intensity for activation of the pituitary-adrenocortical system under normal exercise conditions ischaemic exercise elicited cortisol and T3 responses (concentration increases of 83% and 9.5%, respectively). Ischaemic exercise attenuated the decrease of plasma insulin concentration found under normal conditions. The concentrations of testosterone, TSH and fT4 were not changed significantly during exercise performed in either condition. The results support the suggested essential role of muscle metaboreceptors in the control of hormone responses during muscle activity.
Aim: The purpose of this study was to evaluate the effect of a pre-seasonal 12-week supervised strength training program (SSTP) on arterial stiffiness, brachial and central blood pressure, and ...systolic and diastolic function of the heart in elite powerlifting athletes. Methods: A descriptive study was performed in 19 elite male powerlifters, who exercised for 12 weeks, four days per week with an intensity of 60-90% assessed from 1 repetition maximum and 90-120 min per session. Carotid-femoral pulse wave velocity (cfPWV), augmentation index and central blood pressure were measured by applanation tonometry using the SphygmoCor device, and an echocardiographic examination was performed at baseline and after 12-week SSTP. Results: Subjects' mean brachial and central systolic blood pressure decreased significantly after the training period (132.3+ or -8.8 vs 124.3+ or -8.7 mmHg, p=0.002 and 110.1+ or -7.7 vs 104.5 + or -8.7 mmHg, p=0.008, respectively). Strength training significantly improved systolic tricuspid annular velocity and mitral E/e' ratio (p<0.05). There were no significant differences in cfPWV and augmentation index at baseline and after SSTP. Conclusion: The 12-week supervised strength pre-seasonal training program significantly decreased brachial and central systolic blood pressure in male elite powerlifting athletes. The strength training program decreased left ventricular filling pressure and improved right ventricular systolic function. No significant effect of strength training on aortic stiffiness was found. Keywords: pulse wave velocity, resistance training, cardiovascular health, echocardiography
The purpose of this study was to investigate some anthropometric variables of student candidates of the Institute of Sport Sciences and Physiotherapy, Faculty of Medicine, University of Tartu in ...2017. All anthropometric measurements were made according to the recommendations of R. Martin 7.
Comparison of the height and weight data of the studied subjects with the height and weight norms of Estonia provided by Kaarma et al. 9 revealed that the entrants were taller in height but with the same average weight.
In our study, the somatotypes recommended by Kaarma et al. 9 were used for the first time on entrants to the university. Our study found that male student candidates’ body somatotypes were divided into SD classes as follows: small 8.6%, medium 22.9%, large 18.6%; subtypes of pycnomorphic somatotypes: 7.1% in class I, 1.4% in class II, and 8.6% in class III; leptomorphic somatotypes were divided: 11.4% in class I, none in class II and 31.4% in class III.
Based on the recommendations of several authors, we calculated the ideal body weight for all the entrants enrolled in the study.
Comparison of the average body weight of entrants with the average weight calculated using the ideal weight method revealed an interesting situation. Namely, the mean values calculated using the Devine (1974) formula did not differ statistically significantly from the mean of the measured weights (t=0.101, p> 0.05). Neither did Devine’s (1974) ideal weight and BMI, Rohrer’s index and ponderal index calculated from it, and the body surface calculated according to the formulas of Dubois and Dubois and Mosteller differ from the actual figures.
Aim: The purpose of this study was to evaluate the effect of a pre-seasonal 12-week supervised strength training program (SSTP) on arterial stiffness, brachial and central blood pressure, and ...systolic and diastolic function of the heart in elite powerlifting athletes. Methods: A descriptive study was performed in 19 elite male powerlifters, who exercised for 12 weeks, four days per week with an intensity of 60-90% assessed from 1 repetition maximum and 90-120 min per session. Carotid-femoral pulse wave velocity (cfPWV), augmentation index and central blood pressure were measured by applanation tonometry using the SphygmoCor device, and an echocardiographic examination was performed at baseline and after 12-week SSTP. Results: Subjects' mean brachial and central systolic blood pressure decreased significantly after the training period (132.3+ or -8.8 vs 124.3+ or -8.7 mmHg, p=0.002 and 110.1+ or -7.7 vs 104.5 + or -8.7 mmHg, p=0.008, respectively). Strength training significantly improved systolic tricuspid annular velocity and mitral E/e' ratio (p<0.05). There were no significant differences in cfPWV and augmentation index at baseline and after SSTP. Conclusion: The 12-week supervised strength pre-seasonal training program significantly decreased brachial and central systolic blood pressure in male elite powerlifting athletes. The strength training program decreased left ventricular filling pressure and improved right ventricular systolic function. No significant effect of strength training on aortic stiffness was found. Keywords: pulse wave velocity, resistance training, cardiovascular health, echocardiography
This study examined the possibility that fatigue may modify the hormone responses to exercise. A group of 12 endurance trained athletes ran for 2 h (blood lactate concentrations of approximately 2 ...mmol x l(-1)) in order to induce fatigue. The subjects exercised for 10 min at 70% maximal oxygen uptake before (1st test) and after (2nd test) the 2 h run to assess hormone responsiveness. A 1 min anaerobic power test was performed to assess muscle power. Cortisol, growth hormone, testosterone and insulin concentrations were determined before and after the 1st and 2nd tests. The 1st test resulted in increases in concentrations (P < 0.05) of cortisol and growth hormone, a decrease in insulin concentration (P<0.01) and no change in testosterone concentration. The 2 h run caused decreases of insulin, increases of growth hormone concentration and variable responses in the concentrations of cortisol and testosterone. The 2nd test decreased insulin concentration further (P < 0.05), but responses of the concentrations of testosterone, growth hormone and cortisol were variable. In 6 subjects (group A) cortisol displayed an increase mean (SD) from baseline concentrations + 304.0 (60.0) nmol x l(-1), while in the other 6 subjects (group B) a decrease or no change was seen + 3.1 (5.3) nmol x l(-1), between groups, P<0.05. Growth hormone concentration was substantially higher in group A + 14.7 (4.8) ng x ml(-1) than group B + 6.0 (2.9) ng x ml(-1) following the 2nd test. In group A anaerobic muscle power was higher, while in group B it was lower, after the 2 h run than before the 2 h run (P < 0.05). The findings suggest that fatigue from prolonged endurance activity may introduce a resetting in the pituitary-adrenocortical component of the endocrine system, expressed either by intensified or by suppressed endocrine functions.
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