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1.
Int J Sport Nutr Exerc Metab ; 34(3): 145-153, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38330938

RESUMEN

This study sought to investigate the effect of cold ambient temperature on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and blood flow during steady-state endurance exercise in endurance-trained cyclists. Ten males (age: 23 ± 3 years; peak oxygen consumption: 60.60 ± 4.84 ml·kg-1·min-1; body fat: 18.4% ± 3.5%) participated in baseline lactate threshold (LT) and peak oxygen consumption testing, two familiarization trials, and two experimental trials. Experimental trials consisted of cycling in COLD (3 °C; 42% relative humidity) and neutral (NEU; 19 °C; 39% relative humidity) temperatures. Exercise consisted of 25 min cycling at 70% LT and 25 min at 90% LT. In situ SCAAT lipolysis and blood flow were measured via microdialysis. Heart rate, core temperature, carbohydrate and fat oxidation, blood glucose, and blood lactate were also measured. Heart rate, core temperature, oxygen consumption, and blood lactate increased with exercise but were not different between COLD and NEU. SCAAT blood flow did not change from rest to exercise or between COLD and NEU. Interstitial glycerol increased during exercise (p < .001) with no difference between COLD and NEU. Fat oxidation increased (p < .001) at the onset of exercise and remained elevated thereafter with no difference between COLD and NEU. Carbohydrate oxidation increased with increasing exercise intensity and was greater at 70% LT in COLD compared to NEU (p = .030). No differences were observed between conditions for any other variable. Cycling exercise increased SCAAT lipolysis but not blood flow. Ambient temperature did not alter SCAAT metabolism, SCAAT blood flow, or fat oxidation in well-trained cyclists, though cold exposure increased whole-body carbohydrate oxidation at lower exercise intensities.


Asunto(s)
Tejido Adiposo , Lipólisis , Masculino , Humanos , Adulto Joven , Adulto , Lipólisis/fisiología , Temperatura , Tejido Adiposo/metabolismo , Glucemia/metabolismo , Grasa Abdominal/metabolismo , Lactatos/metabolismo , Consumo de Oxígeno/fisiología , Glicerol , Frío
2.
Curr Opin Clin Nutr Metab Care ; 25(6): 401-406, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36044324

RESUMEN

PURPOSE OF REVIEW: Connective tissue injuries are prevalent in active and aging populations, leading to chronic pain and decreased function. Turnover of this tissue is not well understood, especially as it relates to aging and injury. Supplementation of collagen peptides has been shown to improve connective tissue recovery and pain through increased collagen production. RECENT FINDINGS: Collagen peptide supplementation improves pain and function, and upregulates metabolic pathways associated with muscle and tendon growth. Literature from the past 12-18 months supports that these pathways are also involved with increased synthesis and degradation of collagen and other elements of the extracellular matrix. Improvements in body composition and strength have been noted with collagen peptide supplementation when paired with resistance training. Collagen peptide supplements are hydrolyzed into small peptides, termed bioactive peptides, and individual amino acids. These bioactive peptides are associated with the benefits observed with collagen peptide supplementation and may play a critical role in the collagen turnover. SUMMARY: Collagen peptide supplementation has been shown to promote recovery, decrease pain, and improve strength and body composition when paired with resistance training. These benefits may be attributed to bioactive peptides in collagen peptide supplements. Additional research is warranted to examine the specific effects of these bioactive peptides.


Asunto(s)
Colágeno , Péptidos , Aminoácidos , Colágeno/química , Suplementos Dietéticos , Humanos , Dolor , Péptidos/farmacología , Péptidos/uso terapéutico
3.
Eur J Appl Physiol ; 121(10): 2657-2674, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34131799

RESUMEN

Gastrointestinal symptoms are abundant among athletes engaging in endurance exercise, particularly when exercising in increased environmental temperatures, at higher intensities, or over extremely long distances. It is currently thought that prolonged ischemia, mechanical damage to the epithelial lining, and loss of epithelial barrier integrity are likely contributors of gastrointestinal (GI) distress during bouts of endurance exercise, but due to the many potential causes and sporadic nature of symptoms this phenomenon has proven difficult to study. In this review, we cover known factors that contribute to GI distress symptoms in athletes during exercise, while further attempting to identify novel avenues of future research to help elucidate mechanisms leading to symptomology. We explore the link between the intestinal microbiome, the integrity of the gut epithelia, and add detail on gut hormone and peptide secretion that could potentially contribute to GI distress symptoms in athletes. The influence of nutrition and dietary supplementation strategies are also detailed, where much research has opened up new ideas and potential mechanisms for understanding gut pathophysiology during exercise. The etiology of gastrointestinal symptoms during endurance exercise is multi-factorial with neuroendocrine, microbial, and nutritional factors likely contributing to specific, individualized symptoms. Recent work in previously unexplored areas of both microbiome and gut peptide secretion are pertinent areas for future work, and the numerous supplementation strategies explored to date have provided insight into physiological mechanisms that may be targetable to reduce the incidence and severity of gastrointestinal symptoms in athletes.


Asunto(s)
Terapia por Ejercicio , Ejercicio Físico/fisiología , Enfermedades Gastrointestinales/terapia , Microbiota/fisiología , Microbioma Gastrointestinal/fisiología , Humanos , Resistencia Física/fisiología
4.
J Strength Cond Res ; 35(8): 2321-2326, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34398079

RESUMEN

ABSTRACT: Brown, AF, Alfiero, CJ, Brooks, SJ, Kviatkovsky, SA, Smith-Ryan, AE, and Ormsbee, MJ. Prevalence of normal weight obesity and health risk factors for the female collegiate dancer. J Strength Cond Res 35(8): 2321-2326, 2021-The purpose of this study was to investigate the prevalence of normal weight obesity (NWO) and evaluate the relationship between NWO and health risk factors in a collegiate dancer population. Reanalysis of data of female dancers (N = 42) from 2 larger studies was used to assess prevalence and health risk factors of NWO. Dancers completed a dual-energy x-ray absorptiometry scan to assess fat mass (FM), lean mass (LM), and visceral adipose tissue (VAT) and a 3-day food record. Normal weight obesity was defined as a body mass index (BMI) of 18.5-24.9 kg·m-2 and body fat (BF) ≥30%. Twenty-five (60%) dancers were classified as normal weight lean (NWL), and 17 dancers (40%) were classified as NWO. Significant differences were observed for BMI (NWL: 21.1 ± 1.7, NWO: 23.1 ± 1.6, p < 0.001), LM (NWL: 71.0 ± 2.9%, NWO: 62.5 ± 2.7%, p < 0.001), %BF (NWL: 24.8 ± 3.1%, NWO: 33.9 ± 2.6%, p < 0.001), and VAT (NWL: 130.6 ± 43.0 g, NWO: 232.3 ± 70.8 g, p < 0.001) between NWL and NWO. A significant difference was observed for carbohydrate intake (NWL: 4.7 ± 1.8 g·kg-1, NWO: 3.7 ± 1.0 g·kg-1, p = 0.020) between groups. Significant positive correlations with FM were observed between carbohydrate (kcal, p = 0.048), fat (kcal, p = 0.018; g·kg-1, p = 0.040), and total calories (p = 0.019) in NWO. Normal weight obesity in collegiate dancers may be more prevalent than previously perceived and may be significantly related to important health risk factors. The current study demonstrates the need for body composition assessments and emphasizing on promoting overall health in collegiate dancers.


Asunto(s)
Composición Corporal , Obesidad , Índice de Masa Corporal , Estudios Transversales , Femenino , Humanos , Obesidad/epidemiología , Prevalencia , Factores de Riesgo
5.
J Nutr ; 150(1): 47-54, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31504693

RESUMEN

BACKGROUND: To date, no studies have directly compared the differences between presleep and daytime protein (PRO) consumption on localized and systemic fat metabolism in active women. OBJECTIVE: The purpose of this study was to assess the effects of presleep compared with daytime PRO supplementation on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole-body substrate utilization in women. METHODS: Thirteen young (mean ± SE age: 22 ± 1 y; BMI: 24.3 ± 0.8 kg/m2), resistance-trained [1 repetition maximum (1RM) squat percentage of body weight: 135% ± 6%; 1RM bench press percentage of body weight: 82% ± 4%] women volunteered. On overnight experimental visits, participants performed full-body resistance exercise (RE; 65% 1RM) and were randomly assigned to consume either daytime PRO (PRO, 30 g casein) 30 min post-RE and presleep (30 min before bed) noncaloric, sensory-matched placebo (PLA, 0 g casein) (PRO-PLA), or the opposite (PLA-PRO), switching the order of the supplements on the following visit. SCAAT lipolysis, resting metabolism (indirect calorimetry), and plasma biomarkers (glucose, insulin, nonesterified fatty acids, glycerol) were measured at baseline, overnight, and the next morning. RESULTS: There were no differences in overnight SCAAT lipolysis between conditions indicated by interstitial glycerol concentrations (PRO-PLA: baseline, 669 ± 137; next morning, 321 ± 77.1; PLA-PRO: baseline, 524 ± 109; next morning, 333 ± 68.0 µM), fat oxidation (PRO-PLA: baseline, 5.70 ± 0.35; next morning, 5.00 ± 0.28; PLA-PRO: baseline, 6.59 ± 0.32; next morning, 5.44 ± 0.27 g/min), or any other measure. CONCLUSIONS: There was no difference between the effects of daytime and presleep PRO supplementation on SCAAT lipolysis or whole-body substrate utilization in resistance-trained women. Presleep PRO is a viable option for increasing PRO consumption in resistance-trained women because it does not blunt overnight lipolysis, and will therefore likely not lead to increases in subcutaneous abdominal fat.This trial was registered at clinicaltrials.gov as NCT03573687.


Asunto(s)
Caseínas/administración & dosificación , Fenómenos Cronobiológicos/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Lipólisis , Entrenamiento de Fuerza , Sueño , Caseínas/metabolismo , Fenómenos Cronobiológicos/fisiología , Estudios Cruzados , Proteínas en la Dieta , Método Doble Ciego , Metabolismo Energético , Femenino , Humanos , Oxidación-Reducción , Adulto Joven
6.
Eur J Appl Physiol ; 120(2): 349-357, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31828478

RESUMEN

PURPOSE: To examine the influence of the Ultraman Florida triathlon (3 days of non-continuous racing; stage 1: 10 km swim and 144.8 km cycle; stage 2: 275.4 km cycle; stage 3: 84.4 km run) on circulating plasma concentrations of whole-body (C-reactive protein (CRP), interleukin (IL)-6 (IL-6), and IL-10 and surrogate gut-specific inflammatory markers (IL-17 and IL-23), and determine whether these variables are associated with performance. METHODS: Eighteen triathletes (N = 18; 15 men, 3 women; age: 37 ± 8 yrs) were evaluated at baseline and post-race for circulating concentrations of CRP, IL-6, IL-10, IL-17, and IL-23. Blood samples were drawn two days prior to stage 1 (1600 h) and one day after stage 3 (1200 h). RESULTS: Plasma CRP significantly increased from baseline (1985.8 ± 5962.3 ng/mL) to post-race (27,013.9 ± 12,888.8 ng/mL, p < 0.001, 13-fold increase). Both plasma IL-6 and IL-10 did not significantly change from baseline to post-race. Baseline and post-race concentrations of IL-17 and IL-23 were below detectable limits. Pearson's correlation between mean finish time and post-race IL-10 revealed a significant positive correlation (r = 0.54, p < 0.05). CONCLUSIONS: Our results suggest that cytokines such as IL-6 and IL-10 involved in the inflammatory response return to near-baseline concentrations rapidly even after ultra-endurance events of extreme duration. The absence of IL-17 and IL-23 may suggest positive gut adaptations from ultra-endurance training. A significant positive correlation between post-race IL-10 concentrations and mean finish time may indicate that a relationship between anti-inflammatory responses and performance exists.


Asunto(s)
Tracto Gastrointestinal/metabolismo , Inflamación/sangre , Inflamación/metabolismo , Resistencia Física , Deportes , Adulto , Ciclismo/fisiología , Biomarcadores/sangre , Citocinas/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carrera/fisiología , Natación/fisiología
7.
J Strength Cond Res ; 33(2): 337-345, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28301439

RESUMEN

Ormsbee, MJ, Carzoli, JP, Klemp, A, Allman, BR, Zourdos, MC, Kim, J-S, and Panton, LB. Efficacy of the repetitions in reserve-based rating of perceived exertion for the bench press in experienced and novice benchers. J Strength Cond Res 33(2): 337-345, 2019-Autoregulation (AR) is the practice of adjusting training variables in response to athlete feedback. One component of AR postulated to enhance resistance training adaptations involves implementing a resistance training-specific rating of perceived exertion (RPE) scale measuring repetitions in reserve (RIR). The purpose of this study was to examine the efficacy of this method using the bench press exercise. Twenty-seven college-aged men were assigned to one of 2 groups based on training age: experienced benchers (EB) (n = 14, training age: 4.7 ± 2.0 years) and novice benchers (NB) (n = 13, training age: 1.1 ± 0.6 years). Subjects performed 1 repetition maximum (1RM) followed by single-repetition sets with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% of 1RM. Subjects reported a corresponding RPE, based on RIR, for every set. Average velocity was recorded for each single-repetition set along with the first and last repetitions of the 8-repetition set at 70% of 1RM. Average velocity at 100% of 1RM in EB was slower (0.14 ± 0.04 m·s) compared with NB (0.20 ± 0.05 m·s) (p < 0.001). Experienced benchers recorded greater RPE than NB at 1RM (EB: 9.86 ± 0.14 vs. NB: 9.35 ± 0.36) (p = 0.011). No between-group differences existed for average velocity or RPE at any other intensity. Both EB (r = 0.85, p < 0.001) and NB (r = 0.85, p < 0.001) had strong inverse significant correlations between average velocity and RPE at all intensities. Our findings suggest that the RIR-based RPE scale may be an efficacious approach for AR of bench press training load and volume in college-aged men.


Asunto(s)
Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Levantamiento de Peso/fisiología , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Universidades , Adulto Joven
8.
Br J Nutr ; 120(9): 988-994, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30249314

RESUMEN

The purpose of this study was to determine the effect of a whole-food protein (cottage cheese, CC) consumed before sleep on next-morning resting energy expenditure (REE), RER and appetite compared with an isoenergetic/isonitrogenous casein protein (CP) supplement and placebo (PL) in active women. In a beverage-blinded, randomised, cross-over design, ten active women (age, 23·1 (sd 1·9) years; body fat, 22·0 (sd 4·6) %) consumed pre-sleep CC (30 g of protein, 10 g of carbohydrate and 0 g of fat) or energy- and protein-matched liquid CP or PL (0 kJ). Participants arrived at 18.00 hours for an overnight stay in the laboratory. At 30-60 min before normal bed time (2 h post standard meal), participants consumed CC, CP or PL before measurement of REE. Upon waking (05.00-08.00 hours), REE was repeated and subjective appetite was recorded. Statistical analyses were conducted using repeated-measures ANOVA (SPSS). Significance was accepted at P≤0·05. There were no significant differences in acute REE (CC, 7217 (sd 1368); CP, 7188 (SD 895); PL, 7075 (sd 1108) kJ/d, P=0·95), acute RER (0·79 (sd 0·05), P=0·56), morning REE (CC, 5840 (sd 1225); CP, 5694 (sd 732); PL, 5991 (sd 903) kJ/d, P=0·79) or morning RER (0·77 (sd 0·03), P=0·52). Subjective measures of appetite were not different between groups. In active women, pre-sleep consumption of CC does not alter REE or RER more than a CP or PL beverage. These data suggest that the metabolic response from whole-food protein do not differ from the metabolic response of liquid protein.


Asunto(s)
Apetito , Caseínas/química , Suplementos Dietéticos , Metabolismo Energético , Adulto , Antropometría , Composición Corporal , Estudios Cruzados , Proteínas en la Dieta/administración & dosificación , Ingestión de Energía/efectos de los fármacos , Femenino , Humanos , Estilo de Vida , Descanso , Sueño , Adulto Joven
9.
Int J Sport Nutr Exerc Metab ; 28(6): 619-628, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29485324

RESUMEN

We examined the effect of a protein supplement on muscular strength and body composition during 6 months of a 5 days/week concurrent strength and endurance training program. Sedentary males (n = 26) and females (n = 25), 18-25 years, were randomly assigned to receive a protein (PRO, 42 g/serving) or carbohydrate (CON) supplement twice daily. Strength and body composition (dual-energy X-ray absorptiometry) were assessed at baseline, 3 (3M), and 6 (6M) months. Protein intake was higher in PRO (PRO: 2.2 g/kg; CON: 1.1 g/kg; p < .001). Females in both groups gained similar strength at 3M and 6M in bench press and hip sled. Males in PRO gained more bench press strength at 3M (PRO: 24.6 ± 3.2 kg; CON: 14.3 ± 3.8 kg; p = .06) and 6M (PRO: 34.4 ± 4.3 kg; CON: 18.7 ± 5.1 kg; p = .03) and hip sled strength at 3M (PRO: 67.7 ± 9.2 kg; CON: 40.8 ± 10.8 kg, p = .07) and 6M (PRO: 94.0 ± 10.6 kg; CON: 65.1 ± 12.4 kg; p = .09) compared with CON. Females in PRO experienced a greater reduction in fat mass over the course of the study (6M) than CON (PRO: -1.7 ± 0.5 kg; CON: 0.1 ± 0.5 kg; p = .06). Changes in lean mass were similar for females in PRO and CON. Loss in fat mass was similar for males in PRO and CON at 3M and 6M. Males in PRO gained more lean mass at 3M compared with CON (PRO: 3.2 ± 0.3 kg; CON: 2.2 ± 0.4 kg; p = .1) but similar gains at 6M (PRO: 2.6 ± 0.4 kg; CON: 2.2 ± 0.5 kg; p = .6). The results of this study demonstrate that PRO used during a concurrent training program may augment positive changes in body composition in young sedentary males and females, and strength gains in males.


Asunto(s)
Composición Corporal , Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Fuerza Muscular , Entrenamiento de Fuerza , Absorciometría de Fotón , Femenino , Humanos , Masculino , Adulto Joven
10.
Exp Physiol ; 102(11): 1500-1512, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28795443

RESUMEN

NEW FINDINGS: What is the central question of this study? This study examined the effects of 20 weeks of administration of conjugated linoleic acids/omega-3 fatty acids with or without programed resistance exercise training on body composition, skeletal muscle properties and functional capacity in middle-aged mice fed a high-fat diet. What is the main finding and its importance? Chronic daily administration of conjugated linoleic acids/omega-3 fatty acids with resistance exercise training can help to blunt fat gain, alleviate loss of myogenic capacity and sensorimotor function and lower tissue inflammation in middle-aged mice during chronic high-fat diet-induced catabolism. This study investigated the effects of 20 weeks of combined conjugated linoleic acid (CLA)/omega-3 fatty acid (n-3) administration independently or combined with resistance exercise training (RET) on skeletal muscle in middle-aged mice consuming a high-fat diet (HFD). Nine-month-old C57BL/6 mice were randomly assigned into four experimental groups (H, high-fat diet; HE, H + RET; HCN, H + CLA/n-3; and HECN, H + CLA/n3 + RET). Body composition and functional capacity were assessed pre- and post-intervention. Muscle tissues were collected at 14 months of age. ANOVA was used, with significance set at P ≤ 0.05. Fat mass significantly increased in H (+74%), HE (+142%) and HECN (+43%) but not in HCN. Muscle wet weights were significantly lower in H and HCN than in HE and HECN. Grip strength substantially declined in H (-15%) and HCN (-17%), whereas sensorimotor function significantly declined only in H (-11%). HECN exhibited improvement in strength (+22%) and sensorimotor coordination (+17%). In comparison to H, muscle tumour necrosis factor-α mRNA expression was significantly lower in HE (-39%), HCN (-24%) and HECN (-21%), respectively. Mean myofibre cross-sectional areas were markedly lower in H and HCN than in HE and HECN. H showed significantly lower satellite cell abundance and numbers of myonuclei than all other groups. Our findings suggest that long-term daily CLA/n-3 intake with resistance training improved sensorimotor function, ameliorated fat gain and prevented loss of myogenic capacity while lowering tumour necrosis factor-α expression during chronic HFD.


Asunto(s)
Dieta Alta en Grasa , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Linoleicos Conjugados/administración & dosificación , Músculo Esquelético/efectos de los fármacos , Obesidad/prevención & control , Entrenamiento de Fuerza , Adiposidad/efectos de los fármacos , Factores de Edad , Animales , Caspasa 3/genética , Caspasa 3/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Mediadores de Inflamación/metabolismo , Masculino , Ratones Endogámicos C57BL , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Obesidad/metabolismo , Obesidad/patología , Obesidad/fisiopatología , Desempeño Psicomotor/efectos de los fármacos , Factores de Tiempo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Aumento de Peso/efectos de los fármacos
11.
Eur J Appl Physiol ; 117(5): 913-919, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28303338

RESUMEN

PURPOSE: To investigate the blood glucose kinetics and physiological effects experienced by a type 1 diabetic (T1D) finisher of a 3-day, multi-stage ultra endurance triathlon consisting of a 10 km swim and 144.8 km bike (stage 1), a 275.4 km bike (stage 2), and an 84.4 km run (stage 3). METHODS: The athlete self-monitored blood glucose (SMBG) levels via fingerstick blood draw and hand-held glucometer. Researchers evaluated blood glucose kinetics via a continuous glucose monitoring device. The athlete maintained normal dietary and insulin patterns before, during and after competition daily. Weight and body composition were measured via bioelectrical impedance and select biomarkers were measured in blood. RESULTS: The athlete spent 73.0, 3.4, and 15.1% of during race time in a hyperglycemic state (≥130 mg dL-1) during stages 1, 2, and 3, respectively, and 0.0, 78.6, and 33.6% in a hypoglycemic state (≤80 mg dL-1). Nocturnal glycemic levels showed the athlete spent 86.1, 83.0, and 84.8% of sleep in a hyperglycemic state during nights 1, 2, and 3, respectively, and 9.0, 0.0, and 0.0% in a hypoglycemic state. From pre- to post-race, body weight (73.2 to 76.9 kg) and total body water increased (49.2-51.6 kg). In addition, there were dramatic increases in creatine kinase (271.7-9252.8 µ L-1), cortisol (137.1-270.2 pg mL-1), CRP (188.3-8046.9 ng mL-1), and aldosterone (449.1-1679.6 pg mL-1). CONCLUSIONS: It is possible for a T1D athlete to complete a multi-stage ultraendurance triathlon and maintain glycemic control using SMBG methods. In addition, a T1D athlete participating in an ultraendurance triathlon results in substantial changes in body composition, hormones, and muscle damage.


Asunto(s)
Atletas , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Tolerancia al Ejercicio , Adulto , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Humanos , Insulina/sangre , Masculino , Deportes
12.
Eur J Appl Physiol ; 116(3): 447-58, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26560107

RESUMEN

PURPOSE: The primary purpose of this investigation was to determine the effects of participation in a 3-day multistage ultraendurance triathlon (stage 1 = 10 km swim, 144.8 km bike; stage 2 = 275.4 km bike; stage 3 = 84.4 km run) on body mass and composition, hydration status, hormones, muscle damage, and blood glucose. METHODS: Eighteen triathletes (mean ± SD; age 41 ± 7.5 years; height 175 ± 9 cm; weight 73.5 ± 9.8 kg; male n = 14, female n = 4) were assessed before and after each stage of the race. Body mass and composition were measured via bioelectrical impedance, hydration status via urine specific gravity, hormones and muscle damage via venous blood draw, and blood glucose via fingerstick. RESULTS: Following the race, significant changes included reductions in body mass (qualified effect size: trivial), fat mass (moderate), and percent body fat (small); increases in percent total body water (moderate) and urine specific gravity (large); and unchanged absolute total body water and fat-free mass. There were also extremely large increases in creatine kinase, C-reactive protein, aldosterone and cortisol combined with reductions in testosterone (small) and the testosterone:cortisol ratio (moderate). There were associations between post-race aldosterone and total body water (r = -0.504) and changes in cortisol and fat-free mass (r = -0.536). Finally, blood glucose increased in a stepwise manner prior to each stage. CONCLUSIONS: Participation in Ultraman Florida leads to fluid retention and dramatic alterations in body composition, muscle health, hormones, and metabolism.


Asunto(s)
Composición Corporal , Ejercicio Físico/fisiología , Músculo Esquelético/fisiología , Mialgia/fisiopatología , Equilibrio Hidroelectrolítico , Adulto , Glucemia/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esfuerzo Físico
13.
Clin J Sport Med ; 26(2): 152-6, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25706662

RESUMEN

OBJECTIVE: To compare measures of training, performance, body composition, and areal bone mineral density (aBMD) between age-matched recreational and competitively trained male road cyclists. DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Male cyclists (N = 28) aged 21-54 years riding more than 3 hours per week. ASSESSMENT OF RISK FACTORS: Men who train at high (≥8 h/wk) and moderate volumes (3-8 h/wk). MAIN OUTCOME MEASURES: Areal bone mineral density assessments by dual energy x-ray absorptiometry of the whole body, lumbar spine (L1-L4), right and left hips, maximal oxygen uptake (V[Combining Dot Above]O2max), and training history. RESULTS: Trained cyclists had higher power to weight (5.3 ± 0.4 vs 4.7 ± 0.3 W/kg, P = 0.001), V[Combining Dot Above]O2max (57.2 ± 4.5 vs 53.0 ± 6.1 mL·kg·min, P = 0.049) and training volume (10.6 ± 2.1 vs 6.3 ± 0.9 h/wk, P < 0.001) than recreational cyclists. Trained cyclists had lower right (0.898 ± 0.090 vs 0.979 ± 0.107 g/cm, P = 0.047) and left hip aBMD (0.891 ± 0.079 vs 0.973 ± 0.104 g/cm, P = 0.032). Z-scores identified lumbar (L1-L4) aBMD as osteopenic (-2.5 < Z-score < -1.0) in trained cyclists (-1.39 ± 1.09). Lumbar scans identified 12 trained and 4 recreational cyclists as osteopenic and 3 trained cyclists as osteoporotic. CONCLUSIONS: Areal bone mineral density is lower in trained male road cyclists compared with recreational, specifically at the hips. Lumbar aBMD is low in both trained and recreational cyclists. Research is needed to determine the chronic effects of cycling on aBMD and interventions that improve aBMD in this population. CLINICAL RELEVANCE: This study suggests road cycling may compromise aBMD and potentially increase the likelihood of low-trauma fractures; health care professionals should consider this exposure when exercise prescriptions are designed for patients at-risk for osteopenia/osteoporosis, for example, women and older adults.


Asunto(s)
Atletas/estadística & datos numéricos , Rendimiento Atlético/fisiología , Ciclismo/fisiología , Densidad Ósea , Adulto , Estudios Transversales , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
14.
J Strength Cond Res ; 30(3): 784-91, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26332783

RESUMEN

The primary aim of this study was to compare 2 daily undulating periodization (DUP) models on one-repetition maximum (1RM) strength in the squat, bench press, deadlift, total volume (TV) lifted, and temporal hormone response. Eighteen male, college-aged (21.1 ± 1.9 years) powerlifters participated in this study and were assigned to one of 2 groups: (a) traditional DUP training with a weekly training order: hypertrophy-specific, strength-specific, and power-specific training (HSP, n = 9) or (b) modified DUP training with a weekly training order: hypertrophy-specific, power-specific, and strength-specific training (HPS, n = 9). Both groups trained 3 nonconsecutive days per week for 6 weeks and performed the squat, bench press, and deadlift exercises. During hypertrophy and power sessions, subjects performed a fixed number of sets and repetitions but performed repetitions until failure at a given percentage during strength sessions to compare TV. Testosterone and cortisol were measured at pretesting and posttesting and before each strength-specific day. Hypertrophy, power, and strength produced greater TV in squat and bench press (p ≤ 0.05) than HSP, but not for deadlift (p > 0.05). For squat and deadlift, there was no difference between groups for 1RM (p > 0.05); however, HPS exhibited greater increases in 1RM bench press than HSP (p ≤ 0.05). Effect sizes (ES) showed meaningful differences (ES > 0.50) in favor of HPS for squat and bench press 1RM. Testosterone decreased (p ≤ 0.05) at weeks 5 and 6 and cortisol decline at weeks 3 and 4. However, neither hormone was different at posttesting compared with pretesting (p > 0.05). Our findings suggest that an HPS configuration of DUP has enhanced performance benefits compared with HSP.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza/métodos , Levantamiento de Peso/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Hidrocortisona/sangre , Masculino , Modelos Biológicos , Testosterona/sangre , Adulto Joven
15.
Can J Diet Pract Res ; 77(2): 98-102, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26568150

RESUMEN

PURPOSE: To describe body composition (fat mass (FM) and fat-free mass (FFM)), strength, and nutritional characteristics of patients with hip or knee osteoarthritis undergoing total joint arthroplasty. METHODS: In this prospective pilot study, osteoarthritic patients underwent body composition assessment using bioelectrical impedance analysis, grip strength measurement, and completed a 24-h dietary recall during their pre-operative assessment. RESULTS: Fifty-five patients were included (∼66% females, age 43-89 years). Mean ± SD body mass index (BMI) was 32.79 ± 6.48 kg/m(2) and 62% were obese. Compared with hip osteoarthritis patients, knee osteoarthritis patients had a higher BMI (P = 0.018) and males with knee osteoarthritis had a lower grip strength (P = 0.028). There was a wide range in FM and FFM values across the BMI spectrum. Patients with a higher FM index (FMI, FM/height in m(2)) had higher levels of pain (P = 0.036) and females with higher FMI had a lower grip strength (P = 0.048). Dietary under-reporting was common and many patients did not meet recommendations for protein, vitamins C and E, or omega-3 fatty acids. Those who consumed less protein than the recommended dietary allowance were older (P = 0.018). CONCLUSIONS: A wide variability of body composition and dietary intake was observed which may impact strength and ultimately affect physical function. As such, patients with osteoarthritis may benefit from targeted nutrition and physical activity interventions before and after surgery.


Asunto(s)
Composición Corporal , Dieta , Fuerza de la Mano , Osteoartritis de la Cadera/fisiopatología , Osteoartritis de la Rodilla/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/análisis , Índice de Masa Corporal , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/análisis , Impedancia Eléctrica , Ejercicio Físico , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Grasos Omega-3/análisis , Femenino , Humanos , Masculino , Recuerdo Mental , Persona de Mediana Edad , Estado Nutricional , Obesidad/fisiopatología , Proyectos Piloto , Estudios Prospectivos , Ingesta Diaria Recomendada , Vitamina E/administración & dosificación , Vitamina E/análisis
16.
Nutr J ; 14: 113, 2015 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-26514213

RESUMEN

BACKGROUND: Diets high in either resistant starch or protein have been shown to aid in weight management. We examined the effects of meals high in non-resistant or resistant starch with and without elevated protein intake on substrate utilization, energy expenditure, and satiety in lean and overweight/obese women. METHODS: Women of varying levels of adiposity consumed one of four pancake test meals in a single-blind, randomized crossover design: 1) waxy maize (control) starch (WMS); 2) waxy maize starch and whey protein (WMS+WP); 3) resistant starch (RS); or 4) RS and whey protein (RS+WP). RESULTS: Total post-prandial energy expenditure did not differ following any of the four test meals (WMS = 197.9 ± 8.9; WMS+WP = 188 ± 8.1; RS = 191.9 ± 8.9; RS+WP = 195.8 ± 8.7, kcals/180 min), although the combination of RS+WP, but not either intervention alone, significantly increased (P <0.01) fat oxidation (WMS = 89.5 ± 5.4; WMS+WP = 84.5 ± 7.2; RS = 97.4 ± 5.4; RS+WP = 107.8 ± 5.4, kcals/180 min). Measures of fullness increased (125% vs. 45%) and hunger decreased (55% vs. 16%) following WP supplemented versus non-whey conditions (WMS+WP, RS+WP vs. WMS, RS), whereas circulating hunger and satiety factors were not different among any of the test meals. However, peptide YY (PYY) was significantly elevated at 180 min following RS+WP meal. CONCLUSIONS: The combined consumption of dietary resistant starch and protein increases fat oxidation, PYY, and enhances feelings of satiety and fullness to levels that may be clinically relevant if maintained under chronic conditions. This trial was registered at clinicaltrials.gov as NCT02418429.


Asunto(s)
Grasas de la Dieta/sangre , Proteínas en la Dieta/farmacología , Sobrepeso/sangre , Respuesta de Saciedad/efectos de los fármacos , Almidón/farmacología , Delgadez/sangre , Estudios Cruzados , Dieta/métodos , Proteínas en la Dieta/sangre , Femenino , Humanos , Persona de Mediana Edad , Obesidad/sangre , Obesidad/dietoterapia , Sobrepeso/dietoterapia , Periodo Posprandial/efectos de los fármacos , Almidón/sangre
17.
Aging Clin Exp Res ; 27(4): 403-11, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25647784

RESUMEN

BACKGROUND AND AIMS: Increased adipose tissue may promote catabolic events in skeletal muscle. The aim of this study was to test whether high-fat diet (HFD)-induced obesity would accelerate the onset of muscle wasting in middle-aged mice. METHODS: Muscle was collected from C57BL/6 mice at 9 months of age (baseline) and 14 months of age after consuming a control (C) or HFD. Mice in C and HFD were also subjected to evaluations of body composition and function before and after their respective diets. RESULTS: HFD demonstrated significant (p < 0.05) losses of grip strength (-15 %) and sensorimotor coordination (-11 %), whereas C did not. Lean mass decreased to a greater degree in HFD although not significantly (C: -20.69 ± 7.94 vs. HFD: -31.14 ± 5.49 %, p > 0.05). Gastrocnemius, quadriceps, and hamstrings mass in C and HFD were significantly reduced from baseline (-27 to 43 and -39 to 47 %, respectively, p < 0.05) with no differences between the two; however, soleus mass was lower only in HFD (-24 %, p = 0.03). Myofiber area, satellite cells, and myonuclei of the gastrocnemius were lower only in HFD (-23, -19, and -16 %, respectively, p < 0.05) compared to baseline. CONCLUSIONS: HFD-induced obesity adversely affected function in middle-aged mice. Atrophy of the soleus in HFD but not C suggests sensitivity of oxidative muscle to HFD-dependent catabolism more so than aging. In the muscles containing fast/mixed fibers, aging effects may have concealed the catabolic nature of HFD; however, morphological changes in the gastrocnemius including decreased fiber area, satellite cells, and myonuclei are consistent with an atrophic phenotype related to HFD.


Asunto(s)
Tejido Adiposo , Dieta Alta en Grasa/efectos adversos , Metabolismo/fisiología , Músculo Esquelético , Atrofia Muscular , Obesidad/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Composición Corporal , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/patología , Músculo Esquelético/fisiología , Atrofia Muscular/etiología , Atrofia Muscular/metabolismo , Atrofia Muscular/patología , Obesidad/etiología , Obesidad/patología , Tamaño de los Órganos , Oxidación-Reducción
18.
J Strength Cond Res ; 29(12): 3392-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25992659

RESUMEN

Motocross (MX) is a physically demanding sport with little research concerning the physiological characteristics of these athletes. The purpose of this study was to assess the anthropometric characteristics and performance capabilities of highly trained MX athletes (n = 20; 19 ± 1.6 years) compared with age-matched physically active (PA) men (n = 22; 22 ± 2.9 years). Testing was performed on 2 occasions. The initial visit consisted of a personality assessment in addition to the following (in order): anthropometrics, body composition, anaerobic power/fatigue, isokinetic/isometric strength and fatigue, and flexibility. The second visit consisted of peak oxygen uptake (V[Combining Dot Above]O2peak), handgrip strength, maximum push-ups in 1 minute, extended arm hang time to exhaustion (TTE), and 90° weighted wall-sit tests. All anthropometric and performance data were analyzed using independent samples t-tests to compare group means. Significance was set at p ≤ 0.05. Data are reported as mean ± SD. There were no significant differences between groups in anthropometric or body composition measurements except android fat (MX: 11.7 ± 1.9% vs. PA: 16.4 ± 8.4%, p = 0.04) and biceps circumference (MX: 30.1 ± 2.0 vs. PA: 33.1 ± 3.2 cm, p = 0.001). MX had significantly higher absolute and relative mean anaerobic power (747.3 ± 63.7 vs. 679.7 ± 93.5 W, p = 0.009 and 10.0 ± 0.6 vs. 9.2 ± 1.3 W·kg, p = 0.002, respectively), relative anaerobic peak power (12.7 ± 0.8 vs. 11.9 ± 1.4 W·kg, p = 0.029), TTE (550.1 ± 70.6 vs. 470.1 ± 93.2 seconds, p = 0.004), and extended arm hang duration (113.3 ± 44.9 vs. 73.4 ± 25.3 seconds, p = 0.001). These results suggest highly trained MX athletes possess certain physiological adaptations that likely result from sport-specific demands compared with PA.


Asunto(s)
Atletas , Rendimiento Atlético/fisiología , Composición Corporal/fisiología , Fuerza de la Mano/fisiología , Humanos , Masculino , Fuerza Muscular/fisiología , Consumo de Oxígeno/fisiología , Aptitud Física/fisiología , Adulto Joven
19.
J Strength Cond Res ; 29(12): 3453-65, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26595135

RESUMEN

Although multi-ingredient performance supplements (MIPS) have increased in popularity because of their array of ergogenic ingredients, their efficacy and safety remain in question. The objective of this study was to determine the impact of supplementation with T+ (SUP; Onnit Labs, Austin, TX, USA), an MIPS containing long jack root, beta-alanine, and branched-chain amino acids, and other proprietary blends, on strength, body composition, and hormones in young resistance-trained men. Subjects were randomized to consume either T+ (SUP; n = 14; age, 21 ± 3 years; body fat, 18.3 ± 4.7%) or an isocaloric placebo (PL; n = 13; age, 21 ± 3 years; body fat, 21.5 ± 6.2%) for 4 weeks. Both groups underwent a progressive, 4-week high-intensity resistance training protocol. Before and after the training protocol, mood state, body composition, blood hormones (also collected at midpoint), and maximal strength were measured. SUP had significantly greater increases in bench press (SUP, 102 ± 16 kg to 108 ± 16 kg vs. PL, 96 ± 22 kg to 101 ± 22 kg; p < 0.001) and total weight lifted (SUP, 379 ± 59 kg to 413 ± 60 kg vs. PL, 376 ± 70 kg to 400 ± 75 kg; p < 0.001) compared with PL. Additionally, deadlift strength relative to total body mass (calculated as weight lifted/body mass; kg:kg) (2.08 ± 0.18 to 2.23 ± 0.16; p = 0.036) and lean mass (2.55 ± 0.19 to 2.72 ± 0.16; p = 0.021) increased significantly in SUP but not PL (2.02 ± 0.30 to 2.15 ± 0.36 and 2.56 ± 0.31 to 2.70 ± 0.36, respectively). No other significant differences were detected between groups for the remaining variables. Supplementing with SUP enhanced resistance training adaptations independent of hormonal status, and thus SUP use may warrant inclusion into peri-workout nutrition regimens. This study was registered with clinicaltrials.gov (identifier: NCT01971723).


Asunto(s)
Composición Corporal/efectos de los fármacos , Suplementos Dietéticos , Hormonas/sangre , Fuerza Muscular/efectos de los fármacos , Entrenamiento de Fuerza , Adaptación Fisiológica/efectos de los fármacos , Adolescente , Aminoácidos de Cadena Ramificada/farmacología , Suplementos Dietéticos/efectos adversos , Eurycoma , Humanos , Masculino , Preparaciones de Plantas/farmacología , Raíces de Plantas , Levantamiento de Peso/fisiología , Adulto Joven , beta-Alanina/farmacología
20.
Br J Nutr ; 111(1): 71-7, 2014 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-23768612

RESUMEN

The purpose of the present study was to investigate whether whey protein (WP), casein protein (CP), carbohydrate (CHO) or a non-energy-containing placebo (PLA) consumed before sleep alters morning appetite and resting energy expenditure (REE) in active men. A total of eleven men (age: 23·6 (sem 1·0) years; body fat: 16·3 (sem 2·5) %) participated in this randomised, double-blind, cross-over study. A single dose of WP (30 g), CP (30 g), CHO (33 g) or PLA was consumed 30 min before sleep, and each trial was separated by 48-72 h. The next morning (05.00-08.00 hours), measurements of satiety, hunger and desire to eat and REE were taken. After a 30 min equilibration period, REE in the supine position was measured for 60 min. An analysis of 10 min mean intervals over the final 50 min of the measurement period was conducted. Statistical analyses were conducted using repeated-measures ANOVA for metabolic variables, and a one-way ANOVA was used for measuring changes in appetite markers. Group differences were examined by Tukey's post hoc analysis. There were no significant differences in appetite measures among the groups. There was a main group effect for REE. The predicted REE was significantly greater after consumption of the WP (8151 (sem 67) kJ/d), CP (8126 (sem 67) kJ/d) and CHO (7988 (sem 67) kJ/d) than after that of the PLA (7716 (sem 67) kJ/d, P <0·0001). There were no significant differences between the WP and CP groups in any metabolic measurements. Night-time consumption of WP, CP or CHO, in the hours close to sleep, elicits favourable effects on the next-morning metabolism when compared with that of a PLA in active young men.


Asunto(s)
Apetito/efectos de los fármacos , Metabolismo Basal/efectos de los fármacos , Caseínas/farmacología , Carbohidratos de la Dieta/farmacología , Proteínas en la Dieta/farmacología , Proteínas de la Leche/farmacología , Bocadillos , Adulto , Análisis de Varianza , Composición Corporal , Estudios Cruzados , Método Doble Ciego , Ingestión de Energía/efectos de los fármacos , Humanos , Masculino , Descanso , Saciedad/efectos de los fármacos , Sueño , Proteína de Suero de Leche , Adulto Joven
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