117,311 research outputs found
Comparison of Cardiorespiratory and Metabolic Responses Between Kettlebell Half Marathon and Treadmill Running at the Same Average Oxygen Consumption: A Case Study
No full textPurposesIn kettlebell sport (KS) half marathon, the lift of the kettlebell is required for the highest number of repetitions in 30 min. No data are available on cardiorespiratory and metabolic responses during this exercise routine. The aim of the study was to evaluate cardiopulmonary and metabolic responses to KS half marathon compared to 30 min treadmill running, chosen as a reference paradigm of aerobic exercise, at the same average oxygen consumption (VO2).MethodsA male elite KS athlete was enrolled in two trials separated by 7 days of rest. In the first trial, one-hand long-cycle KS exercise with a 1/3 body weight kettlebell was performed for 30 min (kettlebell half marathon, KT); in the second trial, 30 min treadmill running (TR) was performed at the same average VO2 measured in the first trial (speed 9-10 km/h at 1 degrees uphill inclination). Metabolic and cardiopulmonary assessments [respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE)], blood lactate (BL) kinetics, heart rate (HR), and blood pressure (BP) were measured in both experimental sessions.ResultsThe average VO2 was 33.3 mL/min/kg in KT and 30.6 mL/min/kg in TR. The subject achieved RERpeak 1.17, RERmean 0.98, HRpeak 172 bpm (94% HRmax), HRmean 86% of HRmax, BPpeak 220/100 mmHg in KT, BLpeak 7.2 mmol/L (during trial) in KT and RERpeak 1.13, RERmean 0.89, HRpeak 142 bpm (78% HRmax), HRmean 70% of HRmax, BPpeak 160/80 mmHg, BLpeak 3.5 mmol/L (4 min after trial) mmol/L in TR.ConclusionData indicate that a KS half marathon determines much higher cardiopulmonary and metabolic responses to treadmill running performed at similar VO2
Opinion paper: scientific, philosophical and legal consideration of doping in sports
No full textThe term doping is generally used to indicate practices based on the use of performance-enhancing drugs (PEDs) or the abuse of medical therapies. Mostly analysed by doctors and officials, doping nevertheless also requires a philosophical consideration to avoid being simplistically portrayed as an isolated practice. To do this, we need to pay attention to the contradictions and paradoxes in the modern approach to doping in sport. In this context, doping is not only relevant to the health of an individual involved in the violation of World Anti-Doping Agency (WADA) criteria, but it actually represents a double-edged phenomenon containing ethical and legal points of view. Several philosophical items affect the ethics of doping. While, indeed, through a deontological vision it is easy to morally condemn an athlete who takes the decision to turn to doping, the same condemnation becomes difficult when the practice of doping is compared with the strong social demand of winners in every field of life. This point must be considered to prevent doping from becoming accepted as a daily practice to excel at all costs and regarded not only as normal but as a necessity for those participating in sport at both an amateur and professional level. Furthermore, a complete discussion on doping has to consider not only the philosophy of performance-enhancing drug abuse, but also the widespread practice of an inappropriate and excessive intake of certain dietary supplements with the unique and obsessive purpose (similar to doping) of increasing physical or mental performance. Based on the above, the aim of this paper is to provide a critical opinion of the doping problem and its related practices and analyze possible solutions considering issues that go beyond the impact of doping on health and reflect on whether it is right or not that an athlete does all he can to improve his performance. Graphical Abstract: [Figure not available: see fulltext.]
Thrombolysis enhancing activity of a low molecular weight dermatan sulfate (Desmin 370) in experimental pulmonary embolism in rats.
No full textStudy of the activation and oxygenation of multifidus and gluteus medius muscles during stretching of the lower limb posterior chain: Comparison between two different executions techniques
No full textBackground. Ischiocrural (IC) stretching procedures may result in different involvement of the posterior kinetic chain and of the lumbar spine. Objective. The aim of the study was to evaluate homolateral muscle activation and hemodynamic changes in the Multifidus (MM) and Gluteus medius (GM) muscles in healthy subjects during monolateral IC stretching by using two different execution techniques: technique A (TA: forward bending of the torso, hands in Open Kinetic Chain (OKC), leg stretched) and technique B (TB: forward bending of the torso, leg stretched with knee joint angle of 20°, hands in Closed Kinetic Chain (CKC). Methods. A total of 12 recreationally active males (35-24±4.2 years) and 14 recreational-ly active females (26-22±2.3 years) volunteered to participate in the study and randomly performed TA and TB stretching of 20 s in two subsequent sessions one week apart. During execution, hemodynamic parameters obtained with near infrared spectroscopy (NIRS), namely total hemoglobin (tHb) and tissue oxygen index (TOI%), as indicators of blood flow and oxygen extraction respectively, were detected from homolateral MM, and myoelectric parameters obtained with surface bipolar electromyography (sEMG), namely root mean square (RMS) as indicator of muscle activation, were detected from homolateral GM and MM. Percentage of change (Δ%) was calculated from the beginning and the end of the 20 s recording divided into 5 s epochs for all the parameters measured. Results. All along the 20 s procedure, compared to TB, TA stretching produced higher muscle activation both in MM and GM muscles (p<0.001), and lower tHB% change combined with higher % oxygen extraction in MM (p<0.05). Conclusions. Stretching of the posterior kinetic chain of the lower limbs with 20° bent homolateral knee and hands in CKC prevents MM and GM overload and may represent a useful technique, alternative to classical stretching, to prevent low back pain
Parnaparin reduces the extent of damage in rat brain ischemia : a nuclear magnetic resonance imaging study
No full textMicroalgae production in an industrial-scale photobioreactors plant: A comprehensive Life Cycle assessment
No full textMicroalgae cultivation provides multiple opportunities to produce valuable bioproducts, but greater clarity must be achieved regarding the real sustainability of current technologies. Numerous life cycle assessment (LCA) studies have been conducted so far. However, most of them were based on literature data and/or extrapolations of lab-scale results, while only a few studies used primary data from pilot or full-scale microalgal plants. Moreover, the obtained results showed great variability, leaving the debate on microalgae sustainability fully open. This work presents a thorough LCA based on primary data from an industrial-scale microalgal facility located in Caltagirone, Italy. The plant is based on vertically-stacked horizontal photo bioreactors (total volume of 40.4 m3 ) installed in a greenhouse and has a capacity of 1200 kgDW/y (Chlorella vulgaris). A cradle-to-gate assessment was performed with the functional unit of 1 kgDW biomass, including operational and infrastructural data. The results emphasized the key role in the generation of potential impacts played by cultivation among process stages and by chemicals (nutrients and cleaning agents) and electricity (mainly for agitation and thermoregulation) among flow types. In comparison with studies from the literature, the analysed microalgal plant has an intermediate environmental performance (e.g., global warming potential of 153 kg CO2,eq/ kgDW). This result is encouraging, as it comes from a reliable assessment built on full-scale pri mary data. On the other hand, it highlights the need to explore alternative strategies (e.g., in dustrial symbiosis and circular bioeconomy) to reduce the environmental footprint of the process and enhance its economic attractiveness
Essential amino acids (EAA) mixture supplementation: Effects of an acute administration protocol on myoelectric manifestations of fatigue in the biceps brachii after resistance exercise
No full textBackground: The purpose of this study was to investigate the acute effects of a single oral administration of an essential amino acids enriched mixture (EAA) on myoelectric descriptors of fatigue and maximal force production after a resistance exercise protocol (REP). Methods: Twenty adult males (age: 27 ± 6 years; body mass: 72.7 ± 7.50 kg; height: 1.76 ± 0.06 m) were enrolled in a double-blind crossover placebo-controlled study. Subjects were randomized to receive EAA mix (0.15 g/kg BM) or a placebo (PLA) in two successive trials 7 days apart. In both trials subjects completed a REP 2 h after the ingestion of the EAA mix or PLA. Before ingestion and after REP subjects performed isometric contractions of the dominant upper limb with the elbow joint at 120 degrees: (1) two maximal voluntary contractions (MVCs) for 2-3 s; (2) at 20% MVC for 90 s; (3) at 60% MVC until exhaustion. Mean values of MVC, conduction velocity initial values (CV), fractal dimension initial values (FD), their rates of change (CV slopes, FD slopes) and the Time to perform the Task (TtT) were obtained from a multichannel surface electromyography (sEMG) recording technique. Basal blood lactate (BL) and BL after REP were measured. Results: Following REP a significant decrease of MVC was observed in PLA (P < 0.05), while no statistical differences were found in EAA between pre-REP and post-REP. After REP, although a significant increase in BL was found in both groups (P < 0.0001) a higher BL ?% was observed in PLA compared to EAA (P < 0.05). After REP, at 60% MVC a significant increase of CV rate of change (P < 0.05) was observed in PLA but not in EAA. At the same force level TtT was longer in EAA compared to PLA, with a significant TtT ?% between groups (P < 0.001). Conclusion: Acute EAA enriched mix administration may prevent the loss of force-generating capacity during MVC following a REP. During isometric contraction at 60% MVC after REP the EAA mix may maintain CV rate of change values with a delay in the TtT failure
Correlation between patellar tendon mechanical properties and oxygenation detection by near infrared spectroscopy in males
No full textBackground. The purpose of this study was to determine the correlation between the patellar tendon mechanical properties and oxygenation in healthy men. Methods. In two subsequent sessions, eight (mean age ± SD: 27 ± 4) recreationally active, healthy males performed 4-sec isometric knee extensions of the dominant leg at 20-80% of maximal voluntary contraction (MVC), maintaining a knee joint angle of 90° of flexion. In the first session, B-mode ultrasonography was used to record tendon length, cross-sectional area (CSA), and elongation, parameters needed to calculate stiffness. In the second session, tendon/peritendon hemodynamic parameters, namely total hemoglobin ΔtHb, ΔHHb and tissue oxygenation index (TOI% = O2 Hb/tHb x 100), as indicators of blood flow and oxygen extraction respectively were measured by near infrared spectroscopy (NIRS). Correlations between blood volume (tHB), tissue oxygenation and tendon mechanical properties were tested using Pearson’s correlation coefficient (R). Results. At all % of MVCs, a reduction of tHb and TOI%, and an increase of HHb were observed. At 80% MVC, ΔTOI% was negatively correlated with strain (R =-0.64) and elongation (R =-0.48), whereas a significant positive correlation was found with Young modulus (R = 0.69) and stress (R = 0.62); as regards blood volume, a significant negative correlation was found between elongation and ΔtHb (R =-0.44) and a positive correlation was found between stress and ΔtHb (R = 0.4). Conclusions. Patellar tendon mechanical properties and tendon/peritendon oxygen extraction and blood volume appears to be moderately correlated when studied by ultrasound and NIRS
Environmental sustainability of microalgae-based production systems: Roadmap and challenges towards the industrial implementation
No full textMicroalgae and cyanobacteria are a precious source for the production of biofuels/bioenergy, biomaterials and valuable biochemicals. Beyond photosynthetic CO2 conversion, microalgal systems can involve the valorisation of waste streams and the implementation of green chemistry, industrial symbiosis, and circular bioeconomy approaches. However, their sustainability is uncertain, thus their large-scale application is hindered. The numerous life cycle assessments (LCAs) performed so far are mostly based on data extrapolated from lab-scale experiments or the literature, leading to qualitative and controversial results. This paper reviews primary data-based LCA studies on microalgal pilot to industrial-scale plants. Sixteen studies satisfied the selection criteria, despite they used primary data almost exclusively for cultivation and harvesting. The outlined current status (methodology, inventory, energy performance and environmental impacts) highlighted the lack of uniformity in the applied methods and the presentation of results, as well as some lack of transparency. Nevertheless, the review concluded that electricity consumption and infrastructure are major hotspots. Therefore, the use of renewable energy for supplying the process and of sunlight for biomass photosynthesis should be preferred. The upstream processes produce large impacts. Thus, a suitable reactor, geographic location, and harvesting method should be selected. Biofuels are not competitive in most cases, but some promising multi-product biorefinery scenarios have been presented. To improve the environmental profile of microalgal high-value compounds (e.g., astaxanthin or biostimulants), co product valorisation, waste stream utilization, renewable energy deployment, and compound productivity should be enhanced. More efforts on LCA of large-scale plants are required, especially looking at integrated biorefinery concepts, to take a crucial step towards the implementation of sustainable commercial systems
Nutrition and exercise in a case of carnitine palmitoyl-transferase II deficiency
No full textIn the mild subtype of inherited carnitine palmitoyltransferase II (CPTII) deficiency, muscular mitochondrial fatty acid β-oxidation is impaired. In this condition, interventions involve daily dietary restriction of fats and increase of carbohydrates, whereas physical exercise is commonly contraindicated due to the risk of muscle pain and rhabdomyolysis. We present the case of a 14-year-old female with CPTII deficiency who underwent a 1-h session of unsupervised exercise training for 6 months, 3 days per week, including interval and resistance exercises, after diet assessment and correction. Before and after intervention, the resting metabolic rate (RMR) and respiratory quotient (RQ) were measured by indirect calorimetry, and a cardiopulmonary exercise test (CPET, 10 W/30 s to exhaustion) was performed. Interval training consisted of a 1 min run and a 5 min walk (for 15 min progressively increased to 30 min). During these efforts, the heart rate was maintained over 70% HR max corresponding to respiratory exchange ratio (RER) of 0.98. Resistance training included upper/lower split workouts (3 sets of 8 repetitions each, with 2 min rest between sets). Blood CK was checked before and 36 h after two training sessions chosen randomly without significant difference. After training, RMR increased (+8.1%) and RQ lowered into the physiological range (from 1.0 to 0.85). CPET highlighted an increase of peak power output (+16.7%), aerobic performance (VO2 peak, 8.3%) and anaerobic threshold (+5.7%), oxygen pulse (+4.5%) and a much longer isocapnic buffering duration (+335%). No muscle pain or rhabdomyolysis was reported. Results from our study highlight that training based on short-duration high-intensity exercise improves overall metabolism and aerobic fitness, thus being feasible, at least in a case of CPTII deficiency
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