Ciclismo: fisica e fisiologia - 10 risposte della scienza al ciclista curioso

Consumo di ossigeno e di calorie, potenza ed energia sviluppate, efficienza del motore umano, soglia anaerobica ed acido lattico, velocità ascensionale, pedalata rotonda e a stantuffo, spinta sui pedali, produzione e dispersione del calore corporeo, le resistenze esterne contro cui la bicicletta deve farsi strada, le modifiche morfologiche e fisiologiche che intervengono con l'età, le risposte dei sistemi respiratorio e cardio-vascolare all'esercizio fisico, e tanto altro: per ogni concetto si trova qui una dettagliata spiegazione, attinta dalla fisica e dalla fisiologia

Bioenergetics and Biomechanics of Handcycling at Submaximal Speeds in Athletes with a Spinal Cord Injury

A study aimed at comparing bioenergetics and biomechanical parameters between athletes with tetraplegia and paraplegia riding race handbikes at submaximal speeds in ecological conditions.info:eu-repo/semantics/publishedVersio

The influence of burpee on endurance and short-term memory of adolescents

Aim-The purpose of this study was to assess the effect of the Burpee exercise on the endurance and short-term memory of adolescents aged 15-16 years. Methods-The experiment was performed in a coeducational school in Kirov (Russia). The four-month study involved 52 adolescents of both genders. During the study period, 30 physical education lessons were held in each class. Adolescents from the control group were involved in a typical program (also aimed at improving endurance), and adolescents from the experimental group additionally performed the Burpee exercise. Endurance in adolescents was assessed by means of an "all-out" Running 2000 m test, and short-term memory was assessed by means of the Jacobs test (tests were performed before and after the programs). Results-An analysis of variance revealed an interaction effect (F = 28.733, ηp2 = 0.578 and p < 0.001, and F = 104.353, ηp2 = 0.676 and p < 0.001 for the Running 2000 m test and the Jacobs test, respectively). The control group improved by 1.9% (p > 0.05) in the Running 2000 m and by 5.5% (p > 0.05) in the Jacobs test. In the experimental group, both improved significantly by 8.6% (p < 0.05) in the Running 2000 m test and by 26.0% (p < 0.05) in the Jacobs test. Conclusion-The Burpee exercise could be included in physical education classes to improve endurance and short-term memory in 15-16-year-old

Effects of Goalball on Balance: A Systematic Review

Goalball has been highlighted as a reference disabled sport from educational levels to its participation in the Paralympic Games, where the effects of this sport on balance and its relevance have been investigated. The aim of the systematic review was to systematically review those studies that evaluated the effects of goalball on balance in goalball athletes. A systematic review of PubMed and FECYT (Web of Sciences, CCC, DIIDW, KJD, MEDLINE, RSCI, and SCIELO) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The articles were included if they met the following inclusion criteria: (i) participants were goalball players; (ii) athletes playing goalball; (iii) outcomes were related to balance; and, (iv) original articles without language restriction. From the 85 studies initially identified, 7 were fully reviewed, and their outcome measures were extracted and analyzed. In conclusion, the levels of balance seem to be closely related to the success of competitions, leading coaches to consider its development during training sessions. In this sense, the general practice of goalball may be sufficient at children’s levels, while the practice of 2 days or 5 h per week seems to be an adequate reference. However, athletes with partial levels of visual loss should not be subjected to continuous blinding during training sessions because it could lead to an accelerated reduction in balance levels

Seasonal variations of the relationships between measures of training monotony and strain in professional soccer players

The purposes of this study were (a) to determine the variations in internal and external measures of training monotony (TM) and strain (TS) in professional soccer players according to periods of the season and playing positions, and (b) to analyze the relationships between internal and external measures of TM and TS. Twenty male professional players (age = 29.4 ± 4.4 years) were followed for 20 weeks through session rating of perceived exertion (s-RPE), total distance (TD), high-speed running distance (HSRD) and sprint distance (SpD). Regardless of measure, highest mean TM and TS scores were observed in mid-season and end-season. In general, wingers and strikers tended to have greater values in TM. Midfielders exhibited greater TS of TD and SpD. Correlation results for TM revealed that s-RPE was positively associated with SpD in early-season (r = 0.608) and negatively associated in mid-season (r = - 0.506). Regarding the TS, result demonstrated that s-RPE is negatively associated with HSRD in early-season (r = - 0.464) and positively associated in mid-season (r = 0.476). In general, there different meanings in correlations between internal and external measures across the season. On the one hand, our findings highlighted that TM and TS of professional soccer players is sensitive to period of the season and player's position, but on other hand, correlation analyses proved that changes in one external/internal measure does not cause changes in another external/internal measure which support the constant monitoring of these values across the season

DEVELOPMENT AND TESTING OF A NOVEL HUMAN-POWERED WATERCRAFT FOR PEOPLE WITH LOWER-BODY DISABILITIES

The purpose of this study was to develop a human-powered watercraft for people with lower-body disabilities and investigate its mechanical efficiency and metabolic cost of locomotion. Metabolic variables and mechanical power output was measured during different trials and the results showed a linear correlation between metabolic power and mechanical power. Energy expenditure when pedalling the watercraft was similar to other physical activities performed by people with lower-body disabilities and could as a result, be an alternative fitness tool for those who seek water activities

Editorial: Exercise endocrinology: hormonal variations and relationships with acute and chronic exposure to exercise

[no abstract available

Synergetic effects of a low caffeine dose and pre-exercise music on psychophysical performance in female taekwondo athletes

The ergogenecity of caffeine (CAF) and pre-exercise music have been studied extensively in male and mixed-gender groups, but there is limited information on their synergistic effects in females. This study assessed the effects of combining a low dose of CAF with warm-up music on taekwondo specific performance, perceived exertion (RPE), and psychological aspects in female athletes. In a double-blinded, randomized, placebo-controlled crossover study, 16 female taekwondo athletes (M ± SD; age: 17.69 ± 0.60 years) performed the taekwondo-specific agility test (TSAT), 10 s frequency speed of kick test (FSKT-10s) and its multiple version (FSKT-mult) under the following conditions: 1) no supplement with music (NS+M); 2) no supplement without music (control); 3) CAF without music (CAF+NM), 4) placebo without music (PL+NM), 5) CAF with music (CAF+M), 6) PL with music (PL+M). After each test, athletes rated their RPE, feeling scale (FS), felt arousal scale (FAS) and physical enjoyment (PACES). CAF+M induced better physical performance than other conditions on the FSKT-10s, FSKT-mult, and more desirable psychophysiological responses including RPE post_TSAT, RPE post_FSKT-10s, PACES post_FSKT-10s, FS, FAS post_warm-up, FAS post_FSKT-10s and FAS post_FSKT-mult (all p < 0.05). Except for PL+M, CAF+M also elicited more desirable responses than other conditions for FAS post_TSAT (p < 0.05). Furthermore, CAF+M and CAF+NM conditions enhanced TSAT, PACES post_TSAT, RPE post_FSKT-mult greater than the other conditions (p < 0.05). Preceding warm-up music stimulus with a low dose of CAF may be a more efficient strategy to enhance physical performance and affective valence in female taekwondo athletes compared with using either strategy in isolation

Effect of Physical Guidance on Learning a Tracking Task in Children with Cerebral Palsy

The purpose of this study was to investigate the effect of physical guidance (PG) frequency on learning a tracking task in children with hemiplegic spastic cerebral palsy (CP). For this purpose, 25 children, aged 7–15 years with CP affecting the left side of the body, who were classified in levels II–III of Manual Abilities Classification System (MACS) and levels III–IV of Gross Motor Function Classification System (GMFCS), were recruited from 10 clinical centers. A pre-test including two blocks of 12 trials of the tracking task without any PG was performed by all participants, after that they were assigned into five homogenous groups (with 100%, 75%, 50%, 25%, and 0% of PG) through blocked randomization according to their age. All participants involved in an intervention consisted of eight sessions (four blocks of 12 trials in each session) practicing a tracking task. The 0% PG group received no PG, the 25% PG group received PG for three trials, the 50% PG group received PG for six trials, the 75% PG group received PG for nine trials, and the 100% PG group received PG for all twelve trials. PG consisted of placing the experimenter’s hand around the child’s less-involved hand guiding to stay on the track and complete the task. Learning was inferred by acquisition and delayed retention tests. The results showed that the higher frequency of PG led to more accurate performance during practice phase. However, the group that received 75% PG had significantly better performance compared to the other groups in the retention phase. It is concluded that optimum level of PG, about 75% of trials, can be helpful for learning a tracking task in children with spastic hemiplegic CP, supporting the challenge point framework

Weekly variations of short-duration maximal jumping performance in soccer players: exploring relationships with accumulated training load and match demands

Purpose: The aim of this study was 2-fold: (1) to analyze variations of short-duration maximal jumping performance in players exposed to a match and those who were not and (2) to analyze the relationships between changes in the short-duration maximal jumping performance and different accumulated training load and match demands measures. Methods: Twenty-four professional soccer players (age: 20.3 ± 1.7 years) were monitored daily for their training load and match demands over 6 weeks. In addition, they performed a weekly short-duration maximal jumping performance test (72 h after the last match). Results: Negative moderate correlations were found between percentage of change of countermovement jump (CMJ) height and Acummulated training load (ATL) of total distance (TD), high metabolic load (HML), accelerations (ACC), and decelerations (DEC) (r = -0.38, p = 0.004; r = -0.33, p = 0.013; r = -0.39, p = 0.003; and r = -0.30, p = 0.026). No correlations were found for match load (ML). TD, HML, ACC, and DCC (r = 0.27, r = 0.25, r = 0.31, and r = 0.22, respectively) were used to predict the percentage of change of CMJ height. Conclusion: Match participation has negative effects on CMJ performance. The ATL of HML, ACC, DCC, and TD have a significant influence on both CMJ measures changes. Also, the ATL values of those metrics are the best predictors of the percentage changes of CMJ performance