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1.
Int J Sport Nutr Exerc Metab ; 32(2): 65-73, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34808597

RESUMEN

BACKGROUND: Exercise and vitamin C-enriched collagen supplementation increase collagen synthesis, potentially increasing matrix density, stiffness, and force transfer. PURPOSE: To determine whether vitamin C-enriched collagen (hydrolyzed collagen [HC] + C) supplementation improves rate of force development (RFD) alongside a strength training program. METHODS: Using a double-blinded parallel design, over 3 weeks, healthy male athletes (n = 50, 18-25 years) were randomly assigned to the intervention (HC + C; 20 g HC + 50 mg vitamin C) or placebo (20 g maltodextrin). Supplements were ingested daily 60 min prior to training. Athletes completed the same targeted maximal muscle power training program. Maximal isometric squats, countermovement jumps, and squat jumps were performed on a force plate at the same time each testing day (baseline, Tests 1, 2, and 3) to measure RFD and maximal force development. Mixed-model analysis of variance compared performance variables across the study timeline, whereas t tests were used to compare the change between baseline and Test 3. RESULTS: Over 3 weeks, maximal RFD in the HC + C group returned to baseline, whereas the placebo group remained depressed (p = .18). While both groups showed a decrease in RFD through Test 2, only the treatment group recovered RFD to baseline by Test 3 (p = .036). In the HC + C group, change in countermovement jumps eccentric deceleration impulse (p = .008) and eccentric deceleration RFD (p = .04) was improved. A strong trend was observed for lower limb stiffness assessed in the countermovement jumps (p = .08). No difference was observed in maximal force or squat jump parameters. CONCLUSION: The HC + C supplementation improved RFD in the squat and countermovement jump alongside training.


Asunto(s)
Extremidad Inferior , Fuerza Muscular , Adolescente , Adulto , Ácido Ascórbico/farmacología , Colágeno , Suplementos Dietéticos , Humanos , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Adulto Joven
2.
Int J Sport Nutr Exerc Metab ; 29(2): 73-84, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30952204

RESUMEN

The International Association of Athletics Federations recognizes the importance of nutritional practices in optimizing an Athlete's well-being and performance. Although Athletics encompasses a diverse range of track-and-field events with different performance determinants, there are common goals around nutritional support for adaptation to training, optimal performance for key events, and reducing the risk of injury and illness. Periodized guidelines can be provided for the appropriate type, amount, and timing of intake of food and fluids to promote optimal health and performance across different scenarios of training and competition. Some Athletes are at risk of relative energy deficiency in sport arising from a mismatch between energy intake and exercise energy expenditure. Competition nutrition strategies may involve pre-event, within-event, and between-event eating to address requirements for carbohydrate and fluid replacement. Although a "food first" policy should underpin an Athlete's nutrition plan, there may be occasions for the judicious use of medical supplements to address nutrient deficiencies or sports foods that help the athlete to meet nutritional goals when it is impractical to eat food. Evidence-based supplements include caffeine, bicarbonate, beta-alanine, nitrate, and creatine; however, their value is specific to the characteristics of the event. Special considerations are needed for travel, challenging environments (e.g., heat and altitude); special populations (e.g., females, young and masters athletes); and restricted dietary choice (e.g., vegetarian). Ideally, each Athlete should develop a personalized, periodized, and practical nutrition plan via collaboration with their coach and accredited sports nutrition experts, to optimize their performance.


Asunto(s)
Atletas , Necesidades Nutricionales , Ciencias de la Nutrición y del Deporte , Consenso , Dieta , Suplementos Dietéticos , Ingestión de Energía , Metabolismo Energético , Humanos , Fenómenos Fisiológicos en la Nutrición Deportiva
3.
Int J Sport Nutr Exerc Metab ; 29(5): 526-531, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-30859848

RESUMEN

Nutritional strategies to improve connective tissue collagen synthesis have garnered significant interest, although the scientific validity of these interventions lags behind their hype. This study was designed to determine the effects of three forms of collagen on N-terminal peptide of procollagen and serum amino acid levels. A total of 10 recreationally active males completed a randomized double-blinded crossover design study consuming either placebo or 15 g of vitamin C-enriched gelatin or hydrolyzed collagen (HC), or gummy containing equal parts of gelatin and HC. Supplements were consumed 1 hr before 6 min of jump rope. Blood samples were collected immediately prior to supplement consumption and 4 hr after jump rope. A subset of blood samples (n = 4) was collected for amino acid analysis 1 hr after ingestion. Consumption of an equivalent dose of each supplement increased amino acids in the circulation similarly across all interventions. N-terminal peptide of procollagen levels tended to increase ∼20% from baseline in the gelatin and HC interventions but not the placebo or gummy. These results suggest that vitamin C-enriched gelatin and HC supplementation may improve collagen synthesis when taken 1 hr prior to exercise. However, large variability was observed, which precluded significance for any treatment.


Asunto(s)
Ácido Ascórbico/administración & dosificación , Colágeno/administración & dosificación , Colágeno/biosíntesis , Fenómenos Fisiológicos en la Nutrición Deportiva , Adolescente , Adulto , Aminoácidos/sangre , Estudios Cruzados , Suplementos Dietéticos , Método Doble Ciego , Ejercicio Físico , Humanos , Masculino , Procolágeno/sangre , Adulto Joven
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