Examining the effects of pre-competition rapid weight loss on hydration status and competition performance in elite judo athletes.

The prevalence of rapid weight loss (RWL) among martial arts athletes including judo is very high. Many applied RWL strategies could be dangerous to health and even lead to death. Therefore, the International Judo Federation (IJF) introduced changes in the weigh-in rules, changing the official weigh-in for the day before the competition. Thus, the purpose of this study was to examine the impact of the new IJF rules on hydration status and weight loss strategies among professional judo athletes. Seventeen elite judo athletes participated in the study. Body mass and hydration status, were analyzed before the competition. Moreover, competition result and practice of RWL survey were collected. All subjects reached their weight category limits for the competition. RWL resulted in body mass changes (p < 0.001, ηp2 = 0.79) and dehydration among participants (urine osmolality > 700 [mOsmol*kg]-1 and urine specific gravity > 1.020 [g*cm3]-1). However, urine osmolality (p > 0.05, ηp2 = 0.18), as well as urine specific gravity (p > 0.05, ηp2 = 0.16), at subsequent time points of measurement revealed no statistical differences. The prevalence of RWL was 100%, and only 17.6% of the athletes declared that they would compete in a different weight category if the competition would be conducted on the same day of the weigh-in. All judo athletes applied RWL procedures using traditional methods to achieve the required body mass (i.e., increased exercise, reduced fluid, and food intake). Dehydration state was not associated with competitive performance (p > 0.05).

Exercise-Induced Elevated BDNF Concentration Seems to Prevent Cognitive Impairment after Acute Exposure to Moderate Normobaric Hypoxia among Young Men.

Memory impairment, reduced learning ability, decreased concentration, and psychomotor performance can be all signs of deleterious impact of hypoxia on cognitive functioning. In turn, physical exercise can improve performance and enhance cognitive functions. The purpose of this study was to investigate whether the potential positive effects of exercise performed under normobaric hypoxia can counteract the negative effects of hypoxia on cognitive function, and whether these changes correlate with brain-derived neurotrophic factor (BDNF) concentrations. Seventeen healthy subjects participated in a crossover study where they performed two sessions of single breathing bouts combined with moderate intensity exercise under two conditions: normoxia (NOR EX) and normobaric hypoxia (NH EX). To assess cognitive function, Stroop test was applied. There were no significant differences in any part of the Stroop interference test regardless of the conditions (NOR, NH), despite a statistical decrease in SpO2 (p < 0.0001) under normobaric hypoxic conditions. In addition, a statistical increase (p < 0.0001) in BDNF concentration was observed after both conditions. Acute exercise under normobaric hypoxia did not impair cognitive function despite a significant decrease in SpO2. Exercise in such conditions may offset the negative effects of hypoxia alone on cognitive function. This may be related to the significant increase in BDNF concentration and, as a consequence, positively affect the executive functions.

Stress is not so bad-cortisol level and psychological functioning after 8-week HIIT program during pregnancy: a randomized controlled trial.

Background: Amid extensive pregnancy exercise research, the impact of High Intensity Interval Training (HIIT) on pregnant women's mental health is underexplored. Despite exercise benefits, it can trigger stress responses like elevated cortisol. This study fills the gap by investigating correlations between hair cortisol levels, mental health, and HIIT effects in pregnant women. Methods: We conducted a randomized control trial among 38 Caucasian women in uncomplicated, singleton pregnancy (age 31.11 ± 4.03 years, 21.82 ± 4.30 week of gestation; mean ± SD). The experimental group comprised 22 women engaged in an 8-week high-intensity interval training program (HIIT). The comparative group consisted of 16 pregnant women undergoing an 8-week educational program (EDU). Before and after the interventions, all women were evaluated using the following tools: Hair cortisol level measurements, Beck Depression Inventory - II for depressive symptoms assessment, Childbirth Attitudes Questionnaire for childbirth fear measurement, 12-item Short Form Health Survey to gage health-related quality of life, International Physical Activity Questionnaire for physical activity level estimation, and a Progressive maximal exercise test to evaluate maternal exercise capacity. Results: The key finding of our study reveals that women engaged in the HIIT intervention exhibited a distinct cortisol production pattern in contrast to the EDU group practicing standard moderate intensity physical activity. In the HIIT group, there was an increase in hair cortisol levels, while the EDU group showed a notable decrease. Remarkably, HIIT stimulated cortisol production without adversely impacting fear of childbirth and psychophysical condition during pregnancy. In fact, only the HIIT group showed a significant enhancement in mental health. Conclusion: No links were discovered between hair cortisol levels and the severity of depressive symptoms, psychophysical well-being, or fear of childbirth. Hence, based on our research, employing cortisol levels during pregnancy as an indicator of negative stress or depression risk appears unwarranted.

Effects of Strength Training on BDNF in Healthy Young Adults.

The physical improvements from strength and resistance training have been known for decades, but the cognitive benefits of this type of activity are not as well-known. The aim of this review article is to provide a summary of studies presenting the effects of strength and resistance training on BDNF in healthy young adults. A systematic search of various electronic databases (PubMed, Web of Science, Science Direct and Google Scholar) was conducted in September 2022. Studies that examined associations between strength training and BDNF in healthy young adults aged 18-30 years were included. The final sample included 10 studies published between 2009 and 2020. The results of this literature review are inconclusive. Based on the results of the 10 studies, there is no clear answer as to whether strength training has positive effects on BDNF in healthy young adults.

Improved Oxygen Uptake Efficiency Parameters Are Not Correlated with VO2peak or Running Economy and Are Not Affected by Omega-3 Fatty Acid Supplementation in Endurance Runners.

Peak oxygen uptake (VO2peak) is one of the most reliable parameters of exercise capacity; however, maximum effort is required to achieve this. Therefore, alternative, and repeatable submaximal parameters, such as running economy (RE), are needed. Thus, we evaluated the suitability of oxygen uptake efficiency (OUE), oxygen uptake efficiency plateau (OUEP) and oxygen uptake efficiency at the ventilatory anaerobic threshold (OUE@VAT) as alternatives for VO2peak and RE. Moreover, we evaluated how these parameters are affected by endurance training and supplementation with omega-3 fatty acids. A total of 26 amateur male runners completed a 12-week endurance program combined with omega-3 fatty acid supplementation or medium-chain triglycerides as a placebo. Before and after the intervention, the participants were subjected to a treadmill test to determine VO2peak, RE, OUE, OUEP and OUE@VAT. Blood was collected at the same timepoints to determine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes. OUE correlated moderately or weakly with VO2peak (R2 = 0.338, p = 0.002) and (R2 = 0.226, p = 0.014) before and after the intervention, respectively. There was a weak or no correlation between OUEP, OUE@VAT, VO2peak and RE despite steeper OUE, increased OUEP and OUE@VAT values in all participants. OUE parameters cannot be treated as alternative parameters for VO2peak or RE and did not show changes following supplementation with omega-3 fatty acids in male amateur endurance runners.

Acute Normobaric Hypoxia Lowers Executive Functions among Young Men despite Increase of BDNF Concentration.

BACKGROUND: Decreased SpO2 during hypoxia can cause cognitive function impairment, and the effects of acute hypoxia on high-order brain functions such as executive processing remain unclear. This study's goal was to examine the impact of an acute normobaric hypoxia breathing session on executive function and biological markers. METHODS: Thirty-two healthy subjects participated in a blind study performing two sessions of single 30 min breathing bouts under two conditions (normoxia (NOR) and normobaric hypoxia (NH), FIO2 = 0.135). The Stroop test was applied to assess cognitive function. RESULTS: No significant difference was observed in the Stroop interference in the "reading" part of the test in either condition; however, there was a significant increase in the "naming" part under NH conditions (p = 0.003), which corresponded to a significant decrease in SpO2 (p < 0.001). There was a significant increase (p < 0.013) in the brain-derived neurotrophic factor (BDNF) level after NH conditions compared to the baseline, which was not seen in NOR. In addition, a significant drop (p < 0.001) in cortisol levels in the NOR group and a slight elevation in the NH group was noticed. CONCLUSIONS: According to these findings, acute hypoxia delayed cognitive processing for motor execution and reduced the neural activity in motor executive and inhibitory processing. We also noted that this negative effect was associated with decreased SpO2 irrespective of a rise in BDNF.

Judo training program improves brain and muscle function and elevates the peripheral BDNF concentration among the elderly.

Programmed exercise interventions modulating both physical fitness and cognitive functions have become a promising tool to support healthy aging. The aim of this experiment was to determine the effect of a 12-week judo training (JEX) on cognitive processing and muscle function among the elderly. Forty participants were divided into two groups: the JEX group and the control group (CTL). Before and after 12-week of JEX, participants performed a battery of physiological and psychological tests. The peripheral level of brain-derived neurotrophic factor (BDNF) was analyzed. A 12-week JEX intervention led to improved Stroop performance reflected by a shortening of the response time related to Stroop "naming" interference. In addition, the peripheral concentration of BDNF was significantly increased following the JEX compared with the CTL group. In response to JEX, balance and lower limb strength significantly increased. The current results suggest that JEX could have beneficial effects on cognitive functions, denoted by elevated peripheral BDNF, as well as on balance and strength abilities. A combination of positive effects with respect to movement and cognition makes JEX an ideal preventive lifestyle modification for the aging population.

Effects of Composite Coatings Functionalized with Material Additives Applied on Textile Materials for Cut Resistant Protective Gloves.

The objective of the present work was to evaluate the effects of different types of particles added to a polymer paste applied onto a textile carrier on the cut resistance of the resulting material. Knitted aramid textile samples were coated in laboratory conditions using a polymer paste that was functionalized with 12 types of reinforcing particles of different chemical compositions and size fractions. Cut resistance was tested in accordance with the standard EN ISO 13997:1999 and the results were subjected to statistical analysis. The effects of additive particles on the microstructure of the polymeric layer were assessed by means of scanning electron microscopy. The type and size of the particles affected the cut resistance of the functionalized knitted fabric. They were also found to change the morphology of the porous structure. Composite coatings containing the smallest additive particles exhibited the best cut resistance properties.

Prolonged Sojourn at Very High Altitude Decreases Sea-Level Anaerobic Performance, Anaerobic Threshold, and Fat Mass.

Background: The influence of high altitude on an organism's physiology depends on the length and the level of hypoxic exposure it experiences. This study aimed to determine the effect of a prolonged sojourn at very high altitudes (above 3,500m) on subsequent sea-level physical performance, body weight, body composition, and hematological parameters. Materials and Methods: Ten alpinists, nine males and one female, with a mean age of 27±4years, participated in the study. All had been on mountaineering expeditions to 7,000m peaks, where they spent 30±1days above 3,500m with their average sojourn at 4,900±60m. Their aerobic and anaerobic performance, body weight, body composition, and hematological parameters were examined at an altitude of 100m within 7days before the expeditions and 7days after they descended below 3,500m. Results: We found a significant (p<0.01) decrease in maximal anaerobic power (MAPWAnT) from 9.9±1.3 to 9.2±1.3W·kg-1, total anaerobic work from 248.1±23.8 to 228.1±20.1J·kg-1, anaerobic threshold from 39.3±8.0 to 27.8±5.6 mlO2·kg-1·min-1, body fat mass from 14.0±3.1 to 11.5±3.3%, and a significant increase (p<0.05) in maximal tidal volume from 3.2 [3.0-3.2] to 3.5 [3.3-3.9] L after their sojourn at very high attitude. We found no significant changes in maximal aerobic power, maximal oxygen uptake, body weight, fat-free mass, total body water, hemoglobin, and hematocrit. Conclusion: A month-long exposure to very high altitude led to impaired sea-level anaerobic performance and anaerobic threshold, increased maximal tidal volume, and depleted body fat mass, but had no effect on maximal aerobic power, maximal oxygen uptake, or hemoglobin and hematocrit levels.

Effect of Acute Normobaric Hypoxia Exposure on Executive Functions among Young Physically Active Males.

BACKGROUND: On the one hand, hypoxic exposure may result in progressive brain metabolism disturbance, causing subsequent cognitive impairments. On the other hand, it might also enhance neurogenesis and brain vascularization as well as accelerate cerebral blood flow, leading to cognitive function improvement. The aim of this study was to investigate whether progressive stages of normobaric hypoxia (NH) (FIO2 = 13%, FIO2 = 12%, and FIO2 = 11%) differentially affect post-exposure cognitive performance. METHODS: Fifteen physically active men (age = 23.1 ± 2.1) participated in the study. The Stroop test (ST) was applied to assess cognitive function. To generate NH conditions, a hypoxic normobaric air generator was used. RESULTS: We observed an executive function impairment ("naming" interference p < 0.05) after NH exposure (FIO2 = 13%). After exposure at FIO2 = 12% and FIO2 = 11%, no changes were observed in the Stroop test. Also, changes in SpO2 during subsequent NH exposure were observed. CONCLUSIONS: The current investigation shows that executive functions deteriorate after acute NH exposure and this post-exposure deterioration is not proportional to the normobaric hypoxia stages among young physically active males.

The Specific Judo Training Program Combined With the Whole Body Cryostimulation Induced an Increase of Serum Concentrations of Growth Factors and Changes in Amino Acid Profile in Professional Judokas.

This study aimed to evaluate the effect of a specific training program, supported by 10 sessions of whole body cryostimulation, on growth factors concentrations, amino acids profile and motor abilities in professional judokas. Ultimately, twelve athletes took part in the study. They were randomly assigned to the cryostimulation group (CRY, n = 6) or the control group (CON, n = 6). During 2 weeks of the judo training program, the CRY group performed 10 cryo-sessions (3-min, at a temperature of -110°C) and the CON group rested passively. Anthropometric measurements, a strength test, the Special Judo Efficiency Test (SJET) were assessed 2 days before and after the judo training program. Blood samples were collected at rest, 1 h after the first and the second SJET and 1 h after the first and the last cryo-session to establish growth factors and amino acid concentrations. Lactate level was measured before, immediately after and 1 h after the first and the second SJET. The applied intervention resulted in a significant increase of resting concentrations of brain-derived neurotrophic factor (from 10.23 ± 1.61 to 15.13 ± 2.93 ng⋅ml-1; p = 0.01) and insulin-like growth factor 1 (IGF-1; from 174.29 ± 49.34 to 300.50 ± 43.80 pg⋅ml-1; p = 0.00) in the CRY group. A different response was registered 1 h directly post SJET in the CRY group (a significant increase of IGF-1, interleukin 15 and irisin: p = 0.01; p = 0.00; p = 0.03). Additionally, the significant drop of proline and leucine concentrations in the CRY group was obtained. Athletes' performance remained unchanged in both groups. However, subjects perceived positive changes induced by the intervention - not directly after cryostimulation but in response to the specific training workload. The increase of growth factors concentrations and the improvement of amino acid profile (proline and leucine) contributed to maintaining a high level of muscle function.

Immunological Response and Match Performance of Professional Tennis Players of Different Age Groups During a Competitive Season.

ABSTRACT: Kozlowska, M, Zurek, P, Rodziewicz, E, Góral, K, Zmijewski, P, Lipinska, P, Laskowski, R, Walentukiewicz, AK, Antosiewicz, J, and Ziemann, E. Immunological response and match performance of professional tennis players of different age groups during a competitive season. J Strength Cond Res 35(8): 2255-2262, 2021-We aimed to investigate the effect of physical workloads on immunological response, match performance, and iron metabolism in professional tennis players of different age groups throughout the tournament season and to determine the interdependence of vitamin D status and inflammation. Thirty-eight young, male tennis players with a top national ranking (1-25) participated in this study and were assigned to the following age groups: cadets (CG), juniors (JG), and seniors (SG). Blood samples were collected at the beginning, midpoint, and end of the tournament season to assess the proinflammatory cytokine (tumor necrosis factor-alpha [TNF-α]), anti-inflammatory myokines (interleukin [IL]-6 and IL-10), heat shock proteins (HSP70, HSP27), iron metabolism markers, and vitamin D concentrations. The total number of matches (won and lost) at the national and international events was recorded. The IL-6 and IL-10 concentrations significantly increased across all groups in the middle and end of the tournament season (effect large and very likely). The TNF-α concentration was elevated at the end of the season in CG and SG. The increase in TNF-α concentration corresponded with an increase in hepcidin concentration in these groups. The significant increase in HSP27 concentration was only noticed in SG with normal vitamin D concentrations. In JG and SG, a mild seasonal increase in vitamin D concentration was noted, but still it was insufficient. The immunological response was not affected by the number of tennis matches; however, the anti-inflammatory effect was regulated by higher concentrations of vitamin D. Unexpectedly, most tennis players had vitamin D deficiency. Iron status remained unchanged.

Do Physical Activity and Personality Matter for Hair Cortisol Concentration and Self-Reported Stress in Pregnancy? A Pilot Cross-Sectional Study.

BACKGROUND: Physical activity reduces psychosocial stress in pregnant women. Stress levels might be self-reported (psychosocial) or measured with biomarkers, one of which is hair cortisol concentration (HCC). Additionally, personality has been associated with stress and physical activity. METHODS: The first aim of our study was to explore the differences in self-reported stress assessed by the Perceived Stress Scale (PSS) and in HCC with regard to physical activity level in pregnant (N = 29) and non-pregnant (N = 21) women. The second aim was to analyze the correlations among perceived stress, HCC, frequency of exercise and personality in the two groups separately. RESULTS: There was a significant difference in frequency of exercise and self-reported stress between the two groups, with a lower level in pregnant women, but no differences in HCC and in personality were found. In the group of pregnant women, there was a significant negative correlation between HCC and frequency of exercise sessions, with the latter correlating positively with openness to experience. In the group of non-pregnant women, perceived stress negatively correlated with extraversion, agreeableness and emotional stability. HCC correlated negatively with conscientiousness. CONCLUSIONS: Our findings indicate the importance of physical activity programs dedicated to pregnant women for their life quality.

Significant Predictors of Sports Performance in Elite Men Judo Athletes Based on Multidimensional Regression Models.

BACKGROUND: This research aimed to identify the most significant predictors of sports level using regression modeling. METHODS: This study examined 16 judokas (aged 23 (±2.5)) from four weight categories, with four athletes in each category (66 kg, 73 kg, 81 kg and 90 kg). Each athlete was a member of the Polish National Team, an international master class (IM) or national master class (M). The tests were carried out twice (every two weeks) during the pre-competitive season in the morning, after a 10-min warm-up. The tests were performed according to the following protocol: Explosive Strength Lower Limbs (ExSLL) [W], Strength Endurance Lower Limbs (SELL) [%], Explosive Strength Upper Limbs (ExSUL) [W], Strength Endurance Upper Limbs (SEUL) [%]. The relationships between the dependent variable (ranking score) and the other analyzed variables (predictors) were estimated using the one-factor ridge regression analysis. RESULTS: There were significant intergroup and intragroup differences in the results of explosive strength and strength endurance of the lower and upper limbs. The best predictors were identified using regression modeling: ExSLL, SELL, and SEUL. CONCLUSIONS: Increasing the value of these predictors by a unit should significantly affect the scores in the ranking table. Correlation analysis showed that all variables that are strongly correlated with the Polish Judo Association (PJA) ranking table scores may have an effect on the sports performance.

Short-Term Resistance Training Supported by Whole-Body Cryostimulation Induced a Decrease in Myostatin Concentration and an Increase in Isokinetic Muscle Strength.

The study aimed to determine whether combining cryostimulation with resistance training would effectively increase muscle strength, and if so, whether this adaptation would be related to changes in circulating levels of exerkines (i.e., mediators of systemic adaptation to exercise). Twenty-five students completed 12 sessions of resistance training, each followed by either cryostimulation (n = 15, 3 min exposure at -110 °C) or passive recovery (n = 10). Prior to and post this intervention, participants performed two eccentric cycling bouts (before and after training). At these points, serum concentrations of muscle damage marker (myoglobin), exerkines (interleukin 6 (IL-6), interleukin 15 (IL-15), irisin, brain-derived neurotrophic factor), hypertrophy-related factors (myostatin, insulin-like growth factor 1), and muscle strength were measured. The applied procedure reduced the physiological burden of the second eccentric cycling bout and myoglobin concentrations only in the group subject to cryostimulation. The same group also exhibited decreased levels of myostatin (from 4.7 ± 1.7 to 3.8 ± 1.8 ng·mL-1, p < 0.05). A significant and large interaction between the group × time was noted in IL-15 concentration (p = 0.01, ηp2=0.27). Training and cryostimulation induced a positive and likely significant improvement of isokinetic muscle strength. Altogether, obtained results support the claim that resistance training combined with cold exposure modified muscle strength through modulation of myostatin and IL-15 concentrations.

The Effect of Vitamin D3 Supplementation on Physical Capacity among Active College-Aged Males.

Vitamin D3 supplementation can affect strength and power; however, the effect on both aerobic and anaerobic performance remains unclear. Here, we investigate the effects of eight weeks of a high dose of vitamin D3 supplementation and its impact on circulating 25-hydroxyvitamin D (25-OH-D3) concentrations and selected indicators of physical capacity. Subjects (n = 28, age 21.1 ± 1.6) were divided into two groups: supplemented (SUP), which was given 6000 IU of vitamin D3 daily for eight weeks; and placebo group (PLA). Serum 25-OH-D3 concentrations were determined in pre- and post-intervention. Aerobic (VO2max test) and anaerobic (Wingate Anaerobic Test) capacity were determined before and after the supplementation. The mean baseline concentration of 25-OH-D3 was recognized as deficient (20 ng/mL) and significantly increased over time in the supplemented group (p < 0.01, η2 = 0.86), whilst it remained unchanged in the placebo group. Moreover, the supplementation caused a significant improvement in maximal aerobic (p < 0.05, η2 = 0.27) and anaerobic power (p < 0.01, η2 = 0.51) whereas no changes were observed in PLA group. The VO2max differences were also significant in the supplemented group (p < 0.05). In summary, the changes in aerobic and anaerobic capacity observed in this study were associated with a serum concentration of 25-OH-D3. Our data imply that vitamin D3 supplementation with a dose of 6000 IU daily for eight weeks is sufficient to improve physical capacity and vitamin D3 status.

Changes in Anthropometric Traits and Body Composition Over a Four-Year Period in Elite Female Judoka Athletes.

The aim of the study was to determine changes in the structure and composition of the body in elite female athletes over a four-year period. The study involved 12 female judo athletes with 34 somatic variables evaluated. Anthropometric evaluation was performed twice, first, when the athletes were members of the national junior team (aged 16.64 ± 1.26 years), and second, after four years, when they were members of the national senior team (aged 20.78 ± 1.27 years). The measurements were taken in accordance with the recommendations of the IBP (International Biological Program) with a set of anthropometric instruments (GPM Swiss) while following the Martin-Saller technique. The average body mass, height, BMI, fat free mass (in kg) and body fat content significantly increased, while the percentage of fat free mass significantly decreased. All of the analyzed body circumferences also increased. Increases were recorded in the width of the upper limbs and they were the width of both hands and both elbows. There was also a statistically significant increase in the value of endomorphic and mesomorphic components, while the ectomorphic component value was similar. Body composition and a substantial number of somatic features of female judokas as seniors were not yet set at the junior stage. The predominant type of the body build was the endo-mesomorphic type and changes that occurred in the sample took place mainly in accordance with this tendency.

Acute Sprint Interval Exercise Increases Both Cognitive Functions and Peripheral Neurotrophic Factors in Humans: The Possible Involvement of Lactate.

There is increasing attention to sprint interval exercise (SIE) training as a time-efficient exercise regime. Recent studies, including our own (Kujach et al., 2018), have shown that acute high-intensity intermittent exercise can improve cognitive function; however, the neurobiological mechanisms underlying the effect still remain unknown. We thus examined the effects of acute SIE on cognitive function by monitoring the peripheral levels of growth and neurotrophic factors as well as blood lactate (LA) as potential mechanisms. Thirty-six young males participated in the current study and were divided into two groups: SIE (n = 20; mean age: 21.0 ± 0.9 years) and resting control (CTR) (n = 16; mean age: 21.7 ± 1.3 years). The SIE session consisted of 5 min of warm-up exercise and six sets of 30 s of all-out cycling exercise followed by 4.5 min of rest on a cycling-ergometer. Blood samples to evaluate the changes of serum concentrations of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), and blood LA were obtained at three time points: before, immediately after, and 60 min after each session. A Stroop task (ST) and trail making test (TMT) parts A and B were used to assess cognitive functions. Acute SIE shortened response times for both the ST and TMT A and B. Meanwhile, the peripheral levels of BDNF, IGF-1, and VEGF were significantly increased after an acute bout of SIE compared to those in CTR. In response to acute SIE, blood LA levels significantly increased and correlated with increased levels of BDNF, IGF-1, and VEGF. Furthermore, cognitive function and BDNF are found to be correlated. The current results suggest that SIE could have beneficial effects on cognitive functions with increased neuroprotective factors along with peripheral LA concentration in humans.

Adaptive Changes After 2 Weeks of 10-s Sprint Interval Training With Various Recovery Times.

Purpose: The aim of this study was to compare the effect of applying two different rest recovery times in a 10-s sprint interval training session on aerobic and anaerobic capacities as well as skeletal muscle enzyme activities. Methods: Fourteen physically active but not highly trained male subjects (mean maximal oxygen uptake 50.5 ± 1.0 mlO2·kg-1·min-1) participated in the study. The training protocol involved a series of 10-s sprints separated by either 1-min (SIT10:1) or 4-min (SIT10:4) of recovery. The number of sprints progressed from four to six over six sessions separated by 1-2 days rest. Pre and post intervention anthropometric measurements, assessment of aerobic, anaerobic capacity and muscle biopsy were performed. In the muscle samples maximal activities of citrate synthase (CS), 3-hydroxyacylCoA dehydrogenase (HADH), carnitine palmitoyl-transferase (CPT), malate dehydrogenase (MDH), and its mitochondrial form (mMDH), as well as lactate dehydrogenase (LDH) were determined. Analysis of variance was performed to determine changes between conditions. Results: Maximal oxygen uptake improved significantly in both training groups, by 13.6% in SIT10:1 and 11.9% in SIT10:4, with no difference between groups. Wingate anaerobic test results indicated main effect of time for total work, peak power output and mean power output, which increased significantly and similarly in both groups. Significant differences between training groups were observed for end power output, which increased by 10.8% in SIT10:1, but remained unchanged in SIT10:4. Both training protocols induced similar increase in CS activity (main effect of time p < 0.05), but no other enzymes. Conclusion: Sprint interval training protocols induce metabolic adaptation over a short period of time, and the reduced recovery between bouts may attenuate fatigue during maximal exercise.

Excess postexercise oxygen consumption and fat oxidation in recreationally trained men following exercise of equal energy expenditure: comparisons of spinning and constant endurance exercise.

BACKGROUND: Spinning exercise is one of the most popular types of exercise in fitness industry. Its effects on the post exercise metabolism compared to the isocaloric cyclic endurance exercise are not fully understood. The aim of the present study was to compare the effects of isocaloric (299.1±10.8 kcal) spinning vs. endurance exercise on fat and carbohydrate utilization, glucose, lactate, glycerol and NEFA blood concentration during exercise and recovery. METHODS: Six recreationally active males (age: 23.5±0.71) were tested in two conditions: 1) 30-min spinning; 2) isocaloric continuous exercise. Each trial was followed by a 3-h recovery. Rates of carbohydrate and fat oxidation, the blood glucose, lactate, glycerol and NEFA concentration were assessed at rest, during exercise and recovery. RESULTS: Spinning induced significantly higher fat and lower carbohydrate oxidation rate during a recovery period in comparison to isocaloric endurance exercise trial. Spinning induced almost six-fold higher increase in lipid to carbohydrate oxidation rate ratio at the beginning of second hour of postexercise period in comparison to constant intensity trial and reached similar values at 3 hours after exercise. Blood lactate was higher (P<0.01) at the end of exercise in spinning than continuous exercise (8.57±0.9 vs. 0.72±0.1 mmol·L-1), but became similar at the 60 min of recovery. CONCLUSIONS: These data indicate that spinning induces higher metabolic responses during recovery period, and most effectively shifts the pattern of substrate use toward lipids vs. isocaloric endurance exercise.