scholarly journals Does Vitamin C and E Supplementation Impair the Favorable Adaptations of Regular Exercise?

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Michalis G. Nikolaidis ◽  
Chad M. Kerksick ◽  
Manfred Lamprecht ◽  
Steven R. McAnulty
Keyword(s):  
Free Radicals ◽  
Vitamin C ◽  
Redox Homeostasis ◽  
Training Adaptations ◽  
Radical Production ◽  
Physiological Adaptations ◽  
Contradictory Evidence ◽  
And Performance ◽  
Additional Support ◽  
And Training

The detrimental outcomes associated with unregulated and excessive production of free radicals remains a physiological concern that has implications to health, medicine and performance. Available evidence suggests that physiological adaptations to exercise training can enhance the body’s ability to quench free radicals and circumstantial evidence exists to suggest that key vitamins and nutrients may provide additional support to mitigate the untoward effects associated with increased free radical production. However, controversy has risen regarding the potential outcomes associated with vitamins C and E, two popular antioxidant nutrients. Recent evidence has been put forth suggesting that exogenous administration of these antioxidants may be harmful to performance making interpretations regarding the efficacy of antioxidants challenging. The available studies that employed both animal and human models provided conflicting outcomes regarding the efficacy of vitamin C and E supplementation, at least partly due to methodological differences in assessing oxidative stress and training adaptations. Based on the contradictory evidence regarding the effects of higher intakes of vitamin C and/or E on exercise performance and redox homeostasis, a permanent intake of non-physiological dosages of vitamin C and/or E cannot be recommended to healthy, exercising individuals.

Defining the Volume and Intensity of Sport Participation in Adolescent Rugby Union Players

2008 ◽  
Vol 3 (1) ◽  
pp. 94-106 ◽  
Author(s):  
Timothy B. Hartwig ◽  
Geraldine Naughton ◽  
John Searl
Keyword(s):  
Physical Activity ◽  
Best Practice ◽  
Sport Participation ◽  
Training Session ◽  
Rugby Union ◽  
Gps Tracking ◽  
Training Adaptations ◽  
And Performance ◽  
Tracking Devices ◽  
And Training

Purpose:Investigating adolescent training loads might help us understand optimal training adaptations. GPS tracking devices and training diaries were used to quantify weekly sport and other physical activity demands placed on adolescent rugby union players and profile typical rugby training sessions.Methods:Participants were 75 males age 14 to 18 y who were recruited from rugby teams representing 3 levels of participation: schoolboy, national representative, and a selective sports school talent squad.Results:Schoolboy players covered a distance of (mean ± SD) 3511 ± 836 m, representative-squad players 3576 ± 956 m, and talent-squad players 2208 ± 637 m per rugby training session. The representative squad recorded the highest weekly duration of sport and physical activity (515 ± 222 min/wk), followed by the talent squad (421 ± 211 min/week) and schoolboy group (370 ± 135 min/wk). Profiles of individual players identified as group outliers showed participation in up to 3 games and up to 11 training sessions per week, with twice the weekly load of the team averages.Conclusion:Optimal participation and performance of adolescent rugby union players might be compromised by many high-load, high-impact training sessions and games and commitments to other sports and physical activities. An improved understanding of monitoring and quantifying load in adolescent athletes is needed to facilitate best-practice advice for player management and training prescription.

scholarly journals Pacing in Time-Limited Ultramarathons from 6 to 24 Hours—The Aspects of Age, Sex and Performance Level

2021 ◽  
Vol 13 (5) ◽  
pp. 2705
Author(s):  
Hagen Deusch ◽  
Pantelis T. Nikolaidis ◽  
José Ramón Alvero-Cruz ◽  
Thomas Rosemann ◽  
Beat Knechtle
Keyword(s):  
Analysis Of Variance ◽  
Coefficient Of Variation ◽  
Training Programs ◽  
Performance Level ◽  
Running Speed ◽  
And Performance ◽  
Main Effects ◽  
And Training ◽  
Age And Sex

(1) Background: Compared with marathon races, pacing in time-limited ultramarathons has only been poorly discussed in the literature. The aim of the present study was to analyze the interaction of performance level, age and sex with pacing during 6 h, 12 h or 24 h time-limited ultramarathons. (2) Methods: Participants (n = 937, age 48.62 ± 11.80 years) were the finishers in 6 h (n = 40, 17 women and 23 men), 12 h (n = 232, 77 women and 155 men) and 24 h (n = 665, 166 women and 409 men) ultramarathons. The coefficient of variation (CV), calculated as SD/mean, was used to described pacing. Low scores of CV denoted a more even pacing, and vice versa. A two-way analysis of variance examined the main effects and interactions of sex and race duration on age, race speed and pacing. (3) Results: More men participated in the longer race distances than in the shorter ones and men were older and faster than women. Comparing the 6 h, 12 h and 24 h races, the finishers in the 6 h were the fastest, the finishers in the 12 h were the oldest and the finishers in the 24 h showed the most variable pacing. Furthermore, the faster running speed in the 12 h (women, r = −0.64; men, r = −0.49, p < 0.001) and the 24 h (r = −0.47 in women and men, p < 0.001) was related to less variable pacing. (4) Conclusions: These data might help runners and coaches to choose the the proper duration of a race and training programs for their athletes.

The NAD+ precursor nicotinamide riboside improves redox homeostasis and performance in old mice

2021 ◽  
Vol 165 ◽  
pp. 32
Author(s):  
Ángela G. Correas ◽  
Coralie Arc-Chagnaud ◽  
Adrián De la Rosa ◽  
Aitor Carretero ◽  
Esther García-Domínguez ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Nicotinamide Riboside ◽  
And Performance ◽  
Old Mice

scholarly journals Cultivating the Ethical Repertoires of Behavior Analysts: Prevention of Common Violations

2021 ◽  
Author(s):  
Lisa N. Britton ◽  
Amy A. Crye ◽  
Linda K. Haymes
Keyword(s):  
Behavior Analyst ◽  
Ethical Culture ◽  
Behavior Analyst Certification Board ◽  
Ethical Violations ◽  
Supervision Process ◽  
Organizational Perspective ◽  
Behavior Analysts ◽  
And Performance ◽  
Supervision And Training ◽  
And Training

AbstractViolations of the Professional and Ethical Compliance Code for Behavior Analysts occur despite coursework, supervision, and training. In this discussion, we highlight the most common violation categories identified: (a) improper or inadequate supervision/delegation, (b) failure to report/respond to the Behavior Analyst Certification Board (BACB) as required, and (c) professionalism/integrity. The specific areas addressed under supervision/delegation involve behavior analysts’ standards and performance as supervisors, as well as compliance with coursework. For failure to report, the focus is on responding, reporting, and providing updated information to the BACB in a timely manner. Finally, the section on professionalism and integrity addresses multiple code elements, including integrity, professionalism, and scientific relationships, as well as methods for promoting an ethical culture and decisions involving ethical violations by others. Importantly, we provide guidance on the structure and organization of supervision, methods and guidelines regarding reporting, and rubrics to shape and evaluate professionalism and integrity. We provide recommendations for the supervision process and for practitioners from the organizational perspective so that the organization supports and promotes an ethical culture.

Nutrition and Training Adaptations in Aquatic Sports

2014 ◽  
Vol 24 (4) ◽  
pp. 414-424 ◽  
Author(s):  
Iñigo Mujika ◽  
Trent Stellingwerff ◽  
Kevin Tipton
Keyword(s):  
Body Mass ◽  
Protein Intake ◽  
Metabolic Response ◽  
Nutritional Supplements ◽  
Research Needs ◽  
Training Adaptations ◽  
Protein Timing ◽  
Overload Training ◽  
Protein Ingestion ◽  
And Training

The adaptive response to training is determined by the combination of the intensity, volume, and frequency of the training. Various periodized approaches to training are used by aquatic sports athletes to achieve performance peaks. Nutritional support to optimize training adaptations should take periodization into consideration; that is, nutrition should also be periodized to optimally support training and facilitate adaptations. Moreover, other aspects of training (e.g., overload training, tapering and detraining) should be considered when making nutrition recommendations for aquatic athletes. There is evidence, albeit not in aquatic sports, that restricting carbohydrate availability may enhance some training adaptations. More research needs to be performed, particularly in aquatic sports, to determine the optimal strategy for periodizing carbohydrate intake to optimize adaptations. Protein nutrition is an important consideration for optimal training adaptations. Factors other than the total amount of daily protein intake should be considered. For instance, the type of protein, timing and pattern of protein intake and the amount of protein ingested at any one time influence the metabolic response to protein ingestion. Body mass and composition are important for aquatic sport athletes in relation to power-to-mass and for aesthetic reasons. Protein may be particularly important for athletes desiring to maintain muscle while losing body mass. Nutritional supplements, such as b-alanine and sodium bicarbonate, may have particular usefulness for aquatic athletes’ training adaptation.

Recovery-Stress States of Professional Ballet Dancers During Different Phases of a Ballet Season

2021 ◽  
Author(s):  
Jana S. De Wet ◽  
Eileen Africa ◽  
Ranel Venter
Keyword(s):  
Mixed Model ◽  
High Stress ◽  
Recovery Stress ◽  
Total Recovery ◽  
Ballet Dancers ◽  
Training Adaptations ◽  
Stress States ◽  
Classical Ballet ◽  
And Performance ◽  
Negative Training

Ballet dancers are exposed to chronic high training and performance demands that are associated with overtraining syndrome and injury. Balancing high training loads with recovery to reduce the risk of negative training adaptations is critical. Moreover, the recovery-stress states of professional ballet dancers during training phases of a season are largely unknown. Professional dancers (n = 27) from one classical ballet company in South Africa were monitored for two 8-week phases of a ballet season. A recovery-stress questionnaire for Athletes (RESTQ-76 Sport) was completed weekly during the rehearsal phase (P1) and the performance phase (P2), which took place at the start and the end of the ballet season, respectively. Comparisons were calculated between phases, sexes, and levels of performance with a mixed-model ANOVA and between demographic variables with a one-way ANOVA. The performance phase was signified by lower total recovery (TR, p < 0.01) and higher total stress (TS, p < 0.01) for the group. Female dancers had significantly lower recovery scores than male dancers during P2 (p < 0.01). No differences between levels of performance were found. Subscales previously associated with overreaching and injury were identified in certain groups during P2. In conclusion, P2 was a critical period where dancers, especially females, experienced high stress and low recovery. This could increase the risk for injury and negative training adaptations.

scholarly journals Applicability of Artificial Neural Networks to Predict Mechanical and Permeability Properties of Volcanic Scoria-Based Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Aref M. al-Swaidani ◽  
Waed T. Khwies
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Network Architecture ◽  
Supplementary Cementitious Material ◽  
Natural Pozzolans ◽  
Long Time ◽  
Ann Models ◽  
Artificial Neural ◽  
And Performance ◽  
And Training

Numerous volcanic scoria (VS) cones are found in many places worldwide. Many of them have not yet been investigated, although few of which have been used as a supplementary cementitious material (SCM) for a long time. The use of natural pozzolans as cement replacement could be considered as a common practice in the construction industry due to the related economic, ecologic, and performance benefits. In the current paper, the effect of VS on the properties of concrete was investigated. Twenty-one concrete mixes with three w/b ratios (0.5, 0.6, and 0.7) and seven replacement levels of VS (0%, 10%, 15%, 20%, 25%, 30%, and 35%) were produced. The investigated concrete properties were the compressive strength, the water permeability, and the concrete porosity. Artificial neural networks (ANNs) were used for prediction of the investigated properties. Feed-forward backpropagation neural networks have been used. The ANN models have been established by incorporation of the laboratory experimental data and by properly choosing the network architecture and training processes. This study shows that the use of ANN models provided a more accurate tool to capture the effects of five parameters (cement content, volcanic scoria content, water content, superplasticizer content, and curing time) on the investigated properties. This prediction makes it possible to design VS-based concretes for a desired strength, water impermeability, and porosity at any given age and replacement level. Some correlations between the investigated properties were derived from the analysed data. Furthermore, the sensitivity analysis showed that all studied parameters have a strong effect on the investigated properties. The modification of the microstructure of VS-based cement paste has been observed, as well.

Effect of training on plasma myeloperoxidase concentrations measured before and following intense exercise in Thoroughbred racehorses

2016 ◽  
Vol 12 (1) ◽  
pp. 17-25 ◽  
Author(s):  
R.G. Fonseca ◽  
D.A. Kenny ◽  
B.A. McGivney ◽  
B.A. Murphy ◽  
E.W. Hill ◽  
...  
Keyword(s):  
High Speed ◽  
Venous Blood ◽  
White Blood Count ◽  
Training Intensity ◽  
High Intensity Training ◽  
Thoroughbred Racehorses ◽  
Sampling Points ◽  
And Performance ◽  
Response To Exercise ◽  
And Training

Exercise in horses induces neutrophil degranulation and subsequent increases in plasma myeloperoxidase concentrations (MPO). It is not known whether this response is affected by training or the sampling time in relation to exercise. Our objective was to evaluate plasma MPO concentration at different time points in response to exercise in Thoroughbreds before and following high-intensity training and to evaluate relationships between plasma MPO concentration, physiological measurements and performance. Throughbred racehorses in active training and racing (n=26) performed an exercise test on a high-speed treadmill at least once at the beginning (first three months), middle (second three months) or end (last three months) of a nine month training period with training intensity (number of fast work sessions) collated for each period. Heart rate, speed and distance were recorded and venous blood collected before (T0), during and up to maximal speed (TVmax), 5 min (T5min) and 4 h (T4h) following exercise for measurement of plasma lactate, serum creatine kinase concentration, plasma MPO concentration, white blood count (WBC), neutrophil count (Neut), lymphocyte count and neutrophil percentage (%Neut). WBC increased above T0 values at all sampling points with no training effect. Neut and %Neut increased above T0 values at T4h, while values at TVmax, T5min and T4h increased as training duration increased. Plasma MPO concentration increased above T0 values at all sampling points in response to exercise with all values increasing as training duration increased. Training intensity did not affect any of the measurements, correlations were not identified between any of the biological markers including MPO and physiological and training measurements and no differences were identified between elite versus non-elite horses. It was concluded that plasma MPO concentration is affected by exercise and training duration, and that further investigation of plasma MPO as an assessor of fitness and readiness for competition is warranted.

scholarly journals The Cytoprotective and Cell Recovery Properties of Apple Extracts on H2O2 induced-NIH3T3 Cells: An Anti Aging Candidate

2018 ◽  
Vol 9 (2) ◽  
pp. 78 ◽  
Author(s):  
Nunuk Aries Nurulita ◽  
Anjar Mahardian Kusuma ◽  
Darsini Darsini ◽  
Weny Delvia ◽  
Veby Tri Yulianti
Keyword(s):  
Free Radicals ◽  
Vitamin C ◽  
Protective Effect ◽  
Cell Damage ◽  
Cell Aging ◽  
Fibroblast Cells ◽  
Cell Recovery ◽  
High Concentration ◽  
High Potency ◽  
Nih3t3 Cells

Apple contains high concentration of phenolic compounds that protect cells from oxidative stress. The prolong exposure of free radicals may induce cell damage and premature cell aging. Both local and imported apple contain flavonoid, saponin, tannin, steroid, and terpenoid. The extract of local and imported apples showed low toxicity on NIH3T3 fibroblast cells, with IC50 value of 529 and 463 µg/mL, respectively. Both apple extracts (50 – 250 µg /mL) protected three-day-H2O2 induced-cell damage and cell death. Protective effect was observed as the viability increase of treated cells compared to untreated ones. The protective effect of both extracts were higher than the effect of vitamin C as standard antioxidant at this study. Both apple extracts could reverse cell damage caused by three-hour-high concentration H2O2 exposure, similar with vitamin C. Low concentration of both extracts (50 µg /mL) induced the increase of fibroblast cells’ proliferation kinetics. The extract of imported apple showed higher properties of protective, cell recovery and proliferation of fibroblast cells tha local apple, but not statistically significance. This study concludes that the extract of local and imported apples have high potency in cytoprotective effect and cell recovery of damaged cells caused by free radicals induction. Both apple extracts have high potency to be developed the candidate of antiaging and cells’ regeneration agent.Key words: antiaging, cell recovery, cytoprotective, NIH3T3 cells

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