Anaerobic Energy Research Articles

The Effect Of Different Loads Squat Training On Energy Expenditure Of Young Women

As an important part of fitness program, resistance training is becoming more and more popular among women. However, there are few studies on the energy consumption of female resistance training. PURPOSE:Observing the energy expenditure of female squat under different loads. METHODS:Twelve women (aged 21 ± 2 years) with more than one year of resistance training experience from Beijing Sport University were selected, and the Smith squat 1RM value was more than double their body weight (79.17 ± 6.67 kg). Subjects are required to enter the laboratory 3 hours after the meal, sit and rest for 20 minutes after coming to the laboratory, and collect the oxygen intake at rest, during exercise, and 15 minutes after exercise. Subjects need to complete the Smith barbell squat with low(Smith barbell bar 4 kg and 20% 1RM), medium(40% 1RM and 60% 1RM) and high(70% 1RM and 80% 1RM) load in sequence.Subjects need to draw lots to decide and finish one of the two weight for each load.3 sets for each weight, 5 reps in each set. Squat rhythm is 2 s up and 2 s down, the interval is 4 min in the set, and the interval between different weights is 15 min. Take the peak blood lactic acid of the fingertips after exercise, calculate the difference between the blood lactic acid and the resting level, converting it to the energy consumption of 3 ml of oxygen per kilogram of body weight. RESULTS:(1) The aerobic and anaerobic glycolysis energy consumption during exercise were 5.38 ± 1.23KJ, 3.98 ± 2.25KJ. 20% 1RM were 5.17 ± 1.52KJ, 3.78 ± 1.87KJ. 40% 1RM were 5.78 ± 0.98KJ, 4.69 ± 2.22KJ. 60%1RM were 6.03 ± 1.19KJ, 6.71 ± 2.40KJ. 70% 1RM were 6.47 ± 1.23KJ, 9.37 ± 4.12KJ. 80%1RM were 6.97 ± 1.19KJ, 12.92 ± 5.52KJ. (2)Aerobic energy consumption during exercise:only the energy consumption between low and high loads has a significant difference (p < 0.05). (3) Anaerobic glycolysis energy consumption during exercise:there is a significant difference between high, low and medium load (p < 0.05), and there is no significant difference between the other loads. CONCLUSIONS:(1) The aerobic energy consumption of young women in Smith barbell squat is only significantly different from other loads energy consumption at 70% 1RM and 80% 1RM. (2) During the Smith barbell squat, the energy consumption of anaerobic glycolysis with weight below 60% of 1RM doesn’t increase with the increase in weight.

Characteristics Of Energy Metabolism Of 2 km All-out Rowing Under The Perspective Of National Fitness

PURPOSE: Since the 1970s, Hagerman and Russell et al. have meticulously studied the specific energy supply characteristics of rowing competitions with elite rowers, and their studies all indicate that rowing is a predominantly aerobic energy supply event. However, no studies have been reported on the characteristics of energy supply in 2 km races in a population of non-rowing-specific athletes. In view of this, this paper uses a rowing ergometer to conduct a 2 km all-out rowing test with undergraduate students as participants, aiming to investigate the characteristics of their energy supply. METHODS: Eight healthy non-rowing-specific male students (age 19.8 ± 0.8 yrs, height 176.3 ± 4.5 cm, weight 77 ± 6.4 kg) from a university volunteered to participate in the testing of this study. The participants were asked to complete 2 km in the shortest time on the rowing ergometer (Concept 2, Model D, PM3, USA) in this study. Before the formal test, all participants put on the portable cardiopulmonary function tester(Jaeger,Oxycon Mobile,Germany)and heart rate monitor(Polar,H7,Finland),followed by 15 min of warm-up activity. During the test, the gas metabolism and heart rate were monitored during and 10 min after the 2 km all-out rowing test; after the test, the participants were required to sit still on the ergometer for 10 min. 10uL of fingertip blood was collected for blood lactate analysis (Biosen C-line,EKF,Germany) before the warm-up, before the start of the 2 km all-out row and at 1, 3, 5, 7, 10, 12 and 15 min after the end of the row. The energetic profile in this study was based on the calculation of the energy contributions using the method integrated by Beneke et al. RESULTS: The total energy expenditure was 661.17 ± 40.70 kJ,The anaerobic alactic energy contribution was 30.89 ± 13.44 kJ,the anaerobic lactic energy contribution was 70.41 ± 4.89 KJ;the aerobic energy contribution was 559.87 ± 40.52 KJ. The energy of 2 km all-out rowing was supplied with 4.68% ± 2.05% from anaerobic alactic system, 10.68% ± 0.92% from anaerobic lactic system, 84.64% ± 1.78% from aerobic system. CONCLUSION:The energy of 2 km all-out rowing for undergraduate students was provided mainly by aerobic system, which is consistent with rowing athletes, which further confirms that 2 km rowing is an aerobic dominated event.

Approbation of an innovative method of pretreatment of dark fermentation feedstocks

According to the International Energy Agency, only a small part of the full potential of biomass energy is currently used in the world. The annual amount of agricultural waste in the Russian Federation is estimated at about 152 million tons, and the energy potential of animal waste is 201 PJ/year. Anaerobic digestion is an efficient method of converting organic waste into renewable energy sources. Previously, the positive effect of pretreatment of various organic feedstocks in vortex layer apparatus (VLA) on the characteristics of anaerobic digestion and energy efficiency was shown. Currently, there is a significant interest in the world in obtaining biohydrogen from organic waste using the dark fermentation (DF) process. During pretreatment in the VLA, the iron working bodies are abraded and iron particles are introduced into the feedstock of the DF reactor. This may have a positive effect on the production rate and yield of hydrogen, which has not been previously studied. This work is aimed at evaluating the possibility of using the VLA as a method for pretreatment of a dark fermentation feedstock for the intensification of biohydrogen production. To achieve this goal, an experimental setup was constructed. It consisted of a 45 L DF reactor, a VLA and a process control system to collect data on the DF process parameters every 5 min. At a hydraulic retention time in the DF reactor of 24 h and in the VLA of 30 s, the hydrogen content in the biogas increased from 51.1% to 52.2%. At the same time, the pH increased from 3.85 to 4.8–4.9, and the hydrogen production rate increased by 16% to 1.941 L/(L day). The hydrogen yield was 80.9 ml/g VS. Thus, pretreatment of the feedstock in VLA can be an effective way to intensify the DF process; however, further study of the VLA operating modes is required in order to optimize the concentrations of iron particles introduced into the feedstock for the most efficient continuous production of dark fermentative biohydrogen.

Citizens' willingness to pay for local anaerobic digestion energy: The influence of altruistic value and knowledge

The willingness of citizens to pay for energy from local anaerobic digestion is a difficult and complex process prejudiced by a broad range of factors. This study aims to investigate how citizens' local anaerobic digestion knowledge and altruistic value affects their willingness to pay (WTP) for energy from local anaerobic digestion schemes in Jiangsu province through the impacts of subjective norm and attitude. The theory of reasoned action (TRA) was used to construct the research model. The study compares the original TRA and the current research model. The study collected data from 400 respondents in Jiangsu province, exploiting structural equation modeling techniques in analyzing the data. The results show that citizens' knowledge and altruistic value were positively and significantly related to the subjective norm and attitude towards citizens' WTP for energy from local anaerobic digestion (LAD) schemes. The study revealed that citizens' LAD knowledge and altruistic value positively influence subjective norms and attitudes. The study found that the current research model is better than the original TRA model. The study advocates for marketers of such schemes to establish appropriate techniques to increase citizen trust in their schemes. Also, policymakers should run more campaigns to create environmental concerns on anaerobic digestion in Jiangsu province.

Prolonged cycling lowers subsequent running mechanical efficiency in collegiate triathletes

BackgroundA significant challenge that non-elite collegiate triathletes encounter during competition is the decline in running performance immediately after cycling. Therefore, the purpose of this study was to determine if performing a 40-km bout of cycling immediately before running would negatively influence running economy and mechanical efficiency of running during simulated race conditions in collegiate triathletes.MethodsEight competitive club-level collegiate triathletes randomly performed two trials: cycling for 40 km (Cycle-Run) or running for 5 km (Run–Run), immediately followed by a four-minute running economy and mechanical efficiency of running test at race pace on an instrumented treadmill. Blood lactate, respiratory exchange ratio, mechanical work, energy expenditure, and muscle glycogen were also measured during the four-minute running test.ResultsMechanical efficiency of running, but not running economy, was significantly lower in Cycle-Run, compared to Run–Run (42.1 ± 2.5% vs. 48.1 ± 2.5%, respectively; p = 0.027). Anaerobic energy expenditure was significantly higher in the Cycle-Run trial, compared to the Run–Run trial (16.3 ± 2.4 vs. 7.6 ± 1.1 kJ; p = 0.004); while net (151.0 ± 12.3 vs. 136.6 ± 9.6 kJ; p = 0.204) and aerobic energy expenditure (134.7 ± 12.3 vs. 129.1 ± 10.5 kJ; p = 0.549) were not statistically different between trials. Analysis of blood lactate, respiratory exchange ratio, mechanical work, and changes in muscle glycogen revealed no statistically significant differences between trials.ConclusionsThese results suggest that mechanical efficiency of running, but not running economy, is decreased and anaerobic energy expenditure is increased when a 40-km bout of cycling is performed immediately before running in collegiate triathletes.

What is the physiological impact of reducing the 2,000m Olympic distance in rowing to 1,500m and 1,000m for French young competitive rowers? Insights from the energy system contribution.

French rowing federation reduced the competition distance to 1,500 and 1,000 m in rowers under 16- (U16) and 14-year-old (U14) respectively, to prepare them progressively to the Olympic 2,000 m distance in under 18-year-old (U18). This study aimed to check the hypothesis that relative aerobic (%EAe) and anaerobic (%EAn) energy contributions would be comparable between the competition distances since the more oxidative profile of younger age categories could offset the greater anaerobic contribution induced by shorter rowing races. Thirty-one 12- to 17-year-old competitive rowers performed a race of 2,000, 1,500, or 1,000 m on a rowing ergometer according to their age category. %EAe and %EAn were estimated from oxygen consumption, changes in blood lactate concentration and their energy equivalents. %EAe was lower in U16 than U18 (84.7 vs. 87.0%, p < 0.01), and in U14 than U16 (80.6 vs. 84.7%, p < 0.001). %EAn was higher in U16 than U18 (15.3 vs. 13.0%, p < 0.01), and in U14 than U16 (19.4 vs. 15.3%, p < 0.01). The results did not confirm our initial hypothesis since %EAe and %EAn were significantly different between the race distances, and thus age categories. However, %EAn in U18, U16 and U14 were found to be in the range of values previously found in adult rowers over the 2,000 m Olympic distance (12–30%). Therefore, on a practical level, the strategy implemented by the French rowing federation to reduce the competition distance in the younger age categories could be relevant to progressively prepare them to the physiological requirements encountered over the Olympic distance.

The influence of stochastic temperature fluctuations in shaping the physiological performance of the California mussel, Mytilus californianus.

Climate change is forecasted to increase temperature variability and stochasticity. Most of our understanding of thermal physiology of intertidal organisms has come from laboratory experiments that acclimate organisms to submerged conditions and steady-state increases in temperatures. For organisms experiencing the ebb and flow of tides with unpredictable low tide aerial temperatures, the reliability of reported tolerances and thus predicted responses to climate change requires incorporation of environmental complexity into empirical studies. Using the mussel Mytilus californianus, our study examined how stochasticity of the thermal regime influences physiological performance. Mussels were acclimated to either submerged conditions or a tidal cycle that included either predictable, unpredictable or no thermal stress during daytime low tide. Physiological performance was measured through anaerobic metabolism, energy stores and cellular stress mechanisms just before low tide, and cardiac responses during a thermal ramp. Both air exposure and stochasticity of temperature change were important in determining thermal performance. Glycogen content was highest in the mussels from the unpredictable treatment, but there was no difference in the expression of heat shock proteins between thermal treatments, suggesting that mussels prioritise energy reserves to deal with unpredictable low tide conditions. Mussels exposed to fluctuating thermal regimes had lower gill anaerobic metabolism, which could reflect increased metabolic capacity. Our results suggest that although thermal magnitude plays an important role in shaping physiological performance, other key elements of the intertidal environment complexity such as stochasticity, thermal variability and thermal history are also important considerations for determining how species will respond to climate warming.

The Effects of Water Temperature and Simulated Angling on the Physiological Stress Response of Largemouth Bass

AbstractThe Largemouth Bass Micropterus salmoides, a popular sport fish, is subjected to multiple sublethal stressors during angling, including high water temperature, exercise, handling, live‐well retention, and weigh‐in procedures. Combined effects of ambient and live‐well temperatures on the stress response and recovery from angling‐induced exercise have not been tested in conditions similar to those encountered in tournaments. Therefore, we assessed the effects of ambient temperature (17, 25, and 33°C) and live‐well temperature differential (−4, 0, and +4°C) on the physiological stress response of Largemouth Bass (mean length = 331 mm) at rest, following a simulated angling stressor, and throughout 8 h of recovery in live wells. Stress variables were measured in whole blood (hematocrit, hemoglobin, pH, partial pressure of oxygen [pO2], partial pressure of carbon dioxide [pCO2], Na+, K+, Ca2+, Cl−, and leukocytes) and plasma (cortisol, glucose, lactate, and osmolality). Fish acclimated to 17°C showed the greatest cortisol response after the chasing stressor; however, higher levels of glucose, lactate, pCO2, K+, and monocyte percentage were found at 33°C, and blood pH, Cl−, and lymphocyte percentage were lower at 33°C than at 17°C. When live‐well temperature was manipulated, cortisol levels were highest in fish subjected to the coldest conditions (acclimated to 17°C and retained in 13°C and 17°C live wells) and the warmest condition (acclimated to 33°C and retained in 37°C live wells). However, all fish subjected to the colder extremes survived, whereas 100% mortality occurred in the warmest condition. Besides cortisol, indicators of stress were less pronounced at colder temperatures. Glucose, lactate, and notably K+ concentrations were highest in 37°C live wells, and blood pH, Ca2+, Na+, and Cl− were lowest. Low blood lymphocytes and high monocytes at the warmest conditions indicate reduced immunocompetence or inflammation. Mortality at high temperature may result from exhaustion of aerobic and anaerobic energy sources, failure to recover from metabolic acidosis, and an inability to regain ionic balance.

Concurrent training in team sports: A systematic review

Background: Concurrent strength and endurance training could interfere with adaptation, which primarily affects long-term strength development. However, so far, research on this theme has rarely focused on ways to optimize concurrent strength and endurance training in team sports. Objectives: This paper aims to summarize the literature on the effects of concurrent training on aerobic and anaerobic energy pathways as well as strength and jump performance measures in team sports (invasion games) to provide recommendations for its application. Methods: A systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Various reliable sources with only experimental studies investigating the effect of concurrent training on sport-specific performance measures in team sports (invasion games) were included. Two researchers independently evaluated the risk of bias with the Physiotherapy Evidence Database scale. Results: From 1649 records, 24 were included: 12 in children/adolescents ( n = 428; aged up to 18 years) and 12 in adults ( n = 620; aged 19–30 years), respectively. Thirteen of 24 studies reported improved endurance (V˙O2max, YoYoIR) and strength (CMJ, SJ and 1RM) performance by adding additional resistance training in young and adult team sport players with different training status, and nine of 24 studies reported more pronounced interference effects in older and more experienced players. Discussion: Concurrent training can improve endurance and strength performance in team sports athletes. However, it is revealed that concurrent training can lead to diminished effects, which might be minimized by extended recovery time between sessions, adapted sequencing order and endurance exercise modality. With maturity and developing training status, an increased importance of these variables was documented.

Accuracy of Tracking Devices' Ability to Assess Exercise Energy Expenditure in Professional Female Soccer Players: Implications for Quantifying Energy Availability.

The purpose of the study was to assess the accuracy of commonly used GPS/accelerometer-based tracking devices in the estimation of exercise energy expenditure (EEE) during high-intensity intermittent exercise. A total of 13 female soccer players competing at the highest level in Norway (age 20.5 ± 4.3 years; height 168.4 ± 5.1 cm; weight 64.1 ± 5.3 kg; fat free mass 49.7 ± 4.2 kg) completed a single visit test protocol on an artificial grass surface. The test course consisted of walking, jogging, high-speed running, and sprinting, mimicking the physical requirements in soccer. Three commonly used tracking devices were compared against indirect calorimetry as the criterion measure to determine their accuracy in estimating the total energy expenditure. The anaerobic energy consumption (i.e., excess post-exercise oxygen consumption, EPOC) and resting time were examined as adjustment factors possibly improving accuracy. All three devices significantly underestimated the total energy consumption, as compared to the criterion measure (p = 0.022, p = 0.002, p = 0.017; absolute ICC = 0.39, 0.24 and 0.30, respectively), and showed a systematic pattern with increasing underestimation for higher energy consumption. Excluding EPOC from EEE reduced the bias substantially (all p’s becoming non-significant; absolute ICC = 0.49, 0.54 and 0.49, respectively); however, bias was still present for all tracking devices. All GPS trackers were biased by showing a general tendency to underestimate the exercise energy consumption during high intensity intermittent exercising, which in addition showed a systematic pattern by over- or underestimation during lower or higher exercising intensity. Adjusting for EPOC reduced the bias and provided a more acceptable accuracy. For a more correct EEE estimation further calibration of these devices by the manufacturers is strongly advised by possibly addressing biases caused by EPOC.

Biomechanics of World-Class 800 m Women at the 2017 IAAF World Championships.

The 800 m race challenges the aerobic and anaerobic energy systems, and athletes adopt a technique that allows for running efficiency as well as sprinting speeds. The aim of this novel study was to compare important kinematic variables between the two laps of the 2017 IAAF World Championships women's final. Video data (150 Hz) were collected of all eight finalists on both laps at a distance approximately 50 m from the finish line along the home straight. Running speed, step length, cadence, temporal variables, sagittal plane joint angles, and shank angle at initial contact were measured. Running speed was faster on lap 2 (p = 0.008) because of large increases in cadence (p = 0.012). These higher cadences resulted in large decreases in contact times (p = 0.031) and in flight times (p = 0.016) on lap 2. Greater knee flexion and ankle plantarflexion (p ≤ 0.039) at initial contact on lap 2 seemed partly responsible for shorter swing times (p = 0.016), and which accompanied a decrease in shank angle at initial contact from lap 1 (7°) to a more vertical position on lap 2 (4°) (p = 0.008). Coaches should note that the need for higher cadence, horizontal impulse production during shorter contact times, and the adoption of forefoot striking require strength and neural system training to allow for athletes to increase cadence during the sprint finish. Increasing cadence (and not step length) was the driving factor for faster finishing speeds in the women's 800 m.

Modeling of functional preparedness of women 25-35 years of different somatotypes

Background and Study Aim. The level of functional preparedness of the population is influenced by many factors. The greatest influence is exerted by the economic condition of the country, climatic features of the region, food quality, environmental factor, social status of the population. Therefore, functional readiness standards should be updated periodically. For an objective assessment of functional readiness, all energy potential should be considered: aerobic, anaerobic lactatic and alactatic. Women of different somatotypes have significant differences in the degree of development of indicators of functional preparedness. Hypothesis. The models of functional preparedness developed by us for women of different somatotypes will clearly demonstrate significant differences in the level of preparedness in representatives of different somatotypes. The aim of the study is to develop standards of functional readiness for women aged 25-35 and models of functional preparedness for women of different somatotypes.&#x0D; Material and methods. The study involved women aged 25-35 years (n = 392). Somatotype was determined in all subjects. The power of aerobic energy supply processes was determined by the method of bicycle ergometry according to the PWC 170 test. The threshold of anaerobic metabolism was determined by the test with a stepwise increasing load. The capacity of anaerobic lactatic energy supply processes of muscular activity was determined by a bicycle ergometric 60-second test. The power of anaerobic lactatic and alactatic energy supply processes was determined by Wingate anaerobic tests WAnT 30 and WAnT 10. Standards of functional preparedness were developed according to the author's method based on the rule 3σ.&#x0D; Results. Functional preparedness standards have been developed for women aged 25-35 according to the full range of muscular energy supply regimes. Models of functional preparedness for women 25-35 years of different somatotypes have been developed.&#x0D; Conclusions. The developed standards are based on modern experimental data and consider all human energy potential (aerobic, anaerobic lactatic and anaerobic alactatic). Standards of functional preparedness cannot be universal for different countries and even different regions of large countries.&#x0D; Models of functional preparedness of women of different somatotypes show a significant difference from the standards set for women without somatotype. Somatotype should be considered when assessing indicators of functional preparedness.

Metabolic and physiological demands of 3×3-min-round boxing fights in highly trained amateur boxers.

The aim of this study was to evaluate the energy requirements of the aerobic oxidative, anaerobic lactic (glycolytic), or anaerobic alactic systems in highly trained amateur boxers during a 3×3-min-round boxing fight. On three separate occasions, 10 highly trained male amateur boxers undertook a progressive treadmill run, a progressive bag-punching exercise, and a full-contact competitive boxing fight of the 3×3-min format. Expired gas and heart rate (HR) were recorded throughout all exercise tasks, with the exception of a gas analysis during the competitive fight. Total energy expenditure and the contribution of the three major energy-supply systems were calculated based on oxygen uptake (V̇O<inf>2</inf>) and HR during exercise, blood lactate accumulation, and excess V̇O<inf>2</inf> during the fast phase of the recovery. The blood lactate concentration was >15 (range: 12-18) mmol·L-1 after the fight. The HR reached >93% of the maximal (HR<inf>max</inf>) in rounds 1 and 2 and >97% in the final round and was strongly correlated with HR<inf>max</inf> (r=0.885). The average calculated O<inf>2</inf> uptake during the boxing fight was 89% of V̇O<inf>2max</inf>, whereas O<inf>2</inf> uptake equivalent calculated from the involvement of all three major energy supply systems was 122% of V̇O<inf>2max</inf>. The calculated energy provision during the fight was 73% aerobic, 19% anaerobic alactic and 8% anaerobic glycolytic. In highly trained male amateur boxers, 3×3-min boxing match elicits very high HR and blood lactate levels with predominant involvement of aerobic and substantial contribution of anaerobic alactic energy systems.

Hypoxia Decreases Thermal Sensitivity and Increases Thermal Breadth of Locomotion in the Invasive Freshwater Snail Potamopyrgus antipodarum.

AbstractUnderstanding the physiology of invasive species will contribute to better prediction and prevention measures to avoid the economic and environmental consequences of biological invasions. Predicting the future range of Potamopyrgus antipodarum, a globally invasive aquatic snail, relies on a comprehensive understanding of its physiological tolerances to individual and combined environmental stressors. We conducted a laboratory study to investigate the interacting effects of temperature and dissolved oxygen in shaping the abiotic niche of P. antipodarum. We generated thermal performance curves (7°C-35°C) for resting respiration rate and voluntary locomotor behaviors under normoxia and hypoxia to find the conditions that limited each performance. Extreme high (>30°C) and low (<12°C) temperatures limited respiration and activity, but respiration rate was most oxygen sensitive at low temperatures. Under hypoxic conditions, activity was less thermally sensitive. Increased activity under high temperatures (22°C-28°C) may be fueled by anaerobic metabolism. Relying on anaerobic energy is a time-limited survival strategy, so further warming and deoxygenation of freshwater systems may limit the spread of this very tolerant invasive species.

Features of the Canoeists’ Special Physical Fitness at the Distance of 1000 m

The aim of the study. To better understanding of the indicators of functional support for special endurance and physiological demands in canoeists at a distance of 1000 m. &#x0D; Material and methods: 20 athletes (19-23 years) in canoeing from Shandong and Jiangxi provinces. &#x0D; Results. According to the results of the analysis, the following typological groups of athletes-canoeists, specializing in the distance of 1000 m, with pronounced differences in the implementation of anaerobic energy supply. Typological groups of athletes had no significant differences in aerobic energy capacity (p &gt; 0.05). &#x0D; The first typological group (La max 90s &lt;10.08 mmol·l-1, p &lt; 0.05) is characterized by: power indicators 4.96 ± 2.35 mmol·l-1 and anaerobic energy supply capacity 6.93 ± 3.16 mmol·l-1, which were the lowest among other groups of athletes. Athletes showed significantly low performance in 10-s, 30-s and 90-s tests, and performed less work in the step test, with varying degrees of severity of fatigue compensation mechanisms. &#x0D; The second typological group (La max 90s – 10.08-16.64 mmol·l-1, p &lt; 0.05), is characterized by high power 7.4 ± 1.68 mmol·l-1 and low capacity anaerobic energy supply 13.32 ± 1.52 mmol·l-1. Athletes performed a sufficient amount of work in the step test (3-4 steps), but performance in the 90-s test was reduced, there were reduced characteristics of the ability to compensate for fatigue.&#x0D; The third typological group (La max 90 c-&gt; 16.64 mmol·l-1, p &lt;0.05) is characterized by: power indicators 8.20 ± 2.36 mmol·l-1 and anaerobic energy supply capacity 17.85 ± 1.05 mmol·l-1, which were the highest among other groups of athletes and significantly (p &lt; 0.05) higher performance in 30-s, 90-s tests, and the level of power at which the maximum oxygen consumption in the step test is reached. &#x0D; Conclusion. The results of the studies indicate differences in the level of functional support for special endurance for paddlers of uniform groups for canoeists that specialize in a distance of 1000 m.

Methane formation driven by reactive oxygen species across all living organisms.

Methane (CH4), the most abundant hydrocarbon in the atmosphere, originates largely from biogenic sources1 linked to an increasing number of organisms occurring in oxic and anoxic environments. Traditionally, biogenic CH4 has been regarded as the final product of anoxic decomposition of organic matter by methanogenic archaea. However, plants2,3, fungi4, algae5 and cyanobacteria6 can produce CH4 in the presence of oxygen. Although methanogens are known to produce CH4 enzymatically during anaerobic energy metabolism7, the requirements and pathways for CH4 production by non-methanogenic cells are poorly understood. Here, we demonstrate that CH4 formation by Bacillus subtilis and Escherichia coli is triggered by free iron and reactive oxygen species (ROS), which are generated by metabolic activity and enhanced by oxidative stress. ROS-induced methyl radicals, which are derived from organic compounds containing sulfur- or nitrogen-bonded methyl groups, are key intermediates that ultimately lead to CH4 production. We further show CH4 production by many other model organisms from the Bacteria, Archaea and Eukarya domains, including in several human cell lines. All these organisms respond to inducers of oxidative stress by enhanced CH4 formation. Our results imply that all living cells probably possess a common mechanism of CH4 formation that is based on interactions among ROS, iron and methyl donors, opening new perspectives for understanding biochemical CH4 formation and cycling.

Effect of Computational Method on Accumulated O2 Deficit.

The aim of this study was to examine how relationships between exercise intensity and the rate of energy release established in different ways, affect the calculated O2 deficit accumulated during strenuous exercise. Aerobic energy release is readily measured by the O2 uptake, while anaerobic energy release is by definition independent of O2. The latter is not easily measured during strenuous exercise, but it can be estimated using the accumulated O2 deficit principle. We have calculated it using nine different approaches. Thirteen moderately trained persons (three women) volunteered to serve as subjects for cycle ergometry. Their maximal O2 uptake was 2.9 ± 0.6 mmol s−1 (x̄ ± s; 3.9 ± 0.8 LSTPD min−1). Our reference method (M0) is based on measuring the steady state O2 uptake at the end of at least ten bouts of 10 min of exercise at constant intensity, varying between 30 and 40% of that corresponding to the maximal O2 uptake and up to a power >90% of the maximal O2 uptake, which is a rather time-consuming method. The outcomes of eight different simpler approaches have been compared with those of the reference method. The main result is that the accumulated O2 deficit calculated depends a great deal on the relationship used to calculate it. A protocol of stepwise increases in exercise intensity every 4 min appeared to work well. A gross efficiency method showed the poorest performance. Another important result is that at constant power the O2 uptake continued to increase beyond 4 min of exercise at all powers examined, also at powers well-below those corresponding to the lactate threshold. Finally, the O2 uptake during loadless pedaling was considerably higher than resting O2 uptake, and it appeared to follow a cubic function of the pedaling frequency. In conclusion, to obtain reliable values of the anaerobic energy release using the accumulated O2 deficit principle, reliable relationships between exercise intensity and O2 demand must be established.

Effect of Short-Duration High-Intensity Upper-Body Pre-Load Component on Performance among High-Level Cyclists.

The aim of the present study was to evaluate the effects of upper-body high-intensity exercise priming on subsequent leg exercise performance. Specifically, to compare maximal 4000 m cycling performance with upper-body pre-load (MPThigh) and common warm-up (MPTlow). In this case, 15 high-level cyclists (23.3 ± 3.6 years; 181 ± 7 cm; 76.2 ± 10.0 kg; V˙O2max: 65.4 ± 6.7 mL·kg−1·min−1) participated in the study attending three laboratory sessions, completing an incremental test and both experimental protocols. In MPThigh, warm-up was added by a 25 s high-intensity all-out arm crank effort to the traditional 20-min aerobic warm-up. Both 4000 m maximal bouts started with a 12 s all-out start. Heart rate, blood lactate concentration [La) and spirometric data were measured and analyzed. Overall MPThigh time was slower by 5.3 ± 1.2 s (p < 0.05). [La] at the start was 5.5 ± 1.5 mmol·L−1 higher for MPThigh (p < 0.001) reducing anaerobic energy contribution which was higher in MPTlow during the first and third 1000 m split (p < 0.05). Similarly, MPTlow maintained higher total average power during the entire performance (p < 0.05, d = 0.7). Although the MPThigh condition performed less effectively due to decreased anaerobic capacity, pre-load effect may have the potential to enhance performance at longer distances.

The influence of health-improving running classes on the functional preparedness of women aged 25-35

The article presents a program of training sessions for health running, where the dosage of running loads is based on energy consumption, and describes its impact on the indicators of functional preparedness of women 25-35 years. This technique is based on the dependence of energy expenditure on heart rate. The study involved 80 women of the first period of adulthood who had no experience in sports. The subjects performed running loads in the aerobic mode of energy supply at a heart rate in the range of 140-150 beats per minute. The duration of the running was individual, which provided energy expenditure within the optimal range. In order to harmoniously develop all the energy supply systems of muscular activity, every second and third of the week classes included intense running for short distances in anaerobic power energy supply.&#x0D; The impact of classes on the health-improving running program on the functional preparedness of women aged 25-35 years was manifested by an increase in absolute and relative indicators of aerobic productivity of the body (Vo2 max and TAM). In addition, an increase in the relative indicators of power and capacity of anaerobic lactate productivity of the body (VANT 30 and MQMK). Indicators of anaerobic alactate productivity of the body (VAnT 10abs. and VAnT 10rel.) did not undergo statistically significant changes. Health-improving running classes caused adaptive reactions of the cardiovascular system, which was manifested by a probable decrease in heart rate in a state of relative muscle rest and blood pressure on dosed exercise.&#x0D; Health-improving running classes are an effective way to improve indicators of aerobic productivity of the body in women 25-35 years. The growth of aerobic productivity was facilitated by running loads in the aerobic mode of energy supply, the dosing of which was carried out according to energy consumption. Interval runs of submaximal intensity and serial accelerations contributed to the growth of anaerobic productivity. Such classes cause positive adaptive reactions of the cardiovascular system.

Climbing-Specific Exercise Tests: Energy System Contributions and Relationships With Sport Performance.

PurposeThe aim of the study was to evaluate distinct performance indicators and energy system contributions in 3 different, new sport-specific finger flexor muscle exercise tests.MethodsThe tests included the maximal strength test, the all-out test (30 s) as well as the continuous and intermittent muscle endurance test at an intensity equaling 60% of maximal force, which were performed until target force could not be maintained. Gas exchange and blood lactate were measured in 13 experienced climbers during, as well as pre and post the test. The energy contribution (anaerobic alactic, anaerobic lactic, and aerobic) was determined for each test.ResultsThe contribution of aerobic metabolism was highest during the intermittent test (59.9 ± 12.0%). During continuous exercise, this was 28.1 ± 15.6%, and in the all-out test, this was 19.4 ± 8.1%. The contribution of anaerobic alactic energy was 27.2 ± 10.0% (intermittent), 54.2 ± 18.3% (continuous), and 62.4 ± 11.3% (all-out), while anaerobic lactic contribution equaled 12.9 ± 6.4, 17.7 ± 8.9, and 18.2 ± 9.9%, respectively.ConclusionThe combined analysis of performance predictors and metabolic profiles of the climbing test battery indicated that not only maximal grip force, but also all-out isometric contractions are equally decisive physical performance indices of climbing performance. Maximal grip force reflects maximal anaerobic power, while all-out average force and force time integral of constant isometric contraction at 60% of maximal force are functional measures of anaerobic capacity. Aerobic energy demand for the intermittent exercise is dominated aerobic re-phosphorylation of high-energy phosphates. The force-time integral from the intermittent test was not decisive for climbing performance.