Chronic aerobic exercise prevents high-fructose diet-induced impairment in blood pressure in healthy young adults: a double-blind, randomised clinical trial.

The purpose of the study was to verify the effect of 4 weeks of a high-fructose diet (HFD) associated with aerobic training on the risk factors for cardiometabolic diseases. Twenty-one young adults were randomised into three groups: HFD (HFD: 1 g/kg body weight of fructose/day), high-glucose diet (HGD: 1 g/kg body weight of glucose/day) and high-fructose diet and exercise (HFDE: 1 g/kg body weight of fructose/day + 3 weekly 60-minute sessions of aerobic exercise). Before and after the 4 weeks of the intervention, blood samples were taken and flow-mediated dilatation, insulin resistance index, pancreatic beta cell functional capacity index, insulin sensitivity index and 24-h blood pressure were evaluated. HFD showed an increase in uric acid concentrations (P = 0·040), and HGD and HFDE groups showed no changes in this outcome between pre- and post-intervention; however, the HFDE group showed increased uric acid concentrations from the middle to the end of the intervention (P = 0·013). In addition, the HFD group showed increases in nocturnal systolic blood pressure (SBP) (P = 0·022) and nocturnal diastolic blood pressure (DBP) (P = 0·009). The HGD group exhibited decreases in nocturnal SBP (P = 0·028) and nocturnal DBP (P = 0·031), and the HFDE group showed a decrease in 24-h SBP (P = 0·018). The consumption of 1 g/kg of fructose per day may increase uric acid concentrations and blood pressure in adults. Additionally, aerobic exercises along with fructose consumption attenuate changes in uric acid concentrations and prevent impairment in nocturnal blood pressure.

Effects of high-intensity interval training combined with traditional strength or power training on functionality and physical fitness in healthy older men: A randomized controlled trial.

Concurrent training (CT) is an efficient strategy to improve neuromuscular function and cardiorespiratory fitness in older adults, which are factors of pivotal importance for the maintenance of functional capacity with aging. However, there is a lack of evidence about the effectiveness of power training (PT) as an alternative to traditional strength training (TST) during CT. Thus, the aim of the present study was to examine the effect of 16 weeks (twice weekly) TST combined with high intensity interval training (TST + HIIT) vs. PT combined with HIIT (PT + HIIT) on functional performance, cardiorespiratory fitness and body composition in older men. Thirty five older men (65.8 ± 3.9 years) were randomly allocated into two training groups: TST + HIIT (n = 18), and PT + HIIT (n = 17). TST + HIIT performed resistance training at intensities ranging from 65% to 80% 1RM at slow controlled speed (≅ 2 s for each concentric phase), whereas PT + HIIT trained at intensities ranging from 40% to 60% of 1RM at maximal intentional speed. Both groups performed HIIT at intensities ranging from 75 to 90% of VO2peak. Participants performed functional tests (sit-to-stand, timed-up-and-go, stair climbing); cardiopulmonary exercise testing (maximal cycling power output: Wmax, peak oxygen uptake: VO2peak, cycling economy), as well as body composition assessment (DXA) before, post 8 and post 16 weeks of training. The groups improved similarly (P < 0.05) with training in all functional capacity outcomes, Wmax, cycling economy, VO2peak and body composition (P < 0.05). These findings suggest that HIIT based CT programs involving TST vs. PT are equally effective in improving functionality, cardiorespiratory fitness and body composition in healthy older men.

Predictive equations for evaluation for resting energy expenditure in Brazilian patients with type 2 diabetes: what can we use?

BACKGROUND: Evaluation of the resting energy expenditure (REE) is essential to ensure an appropriate dietary prescription for patients with type 2 diabetes. The aim of this record was to evaluate the accuracy of predictive equations for REE estimation in patients with type 2 diabetes, considering indirect calorimetry (IC) as the reference method. METHODS: A cross-sectional study was performed in outpatients with type 2 diabetes. Clinical, body composition by electrical bioimpedance and laboratory variables were evaluated. The REE was measured by IC (QUARK RMR, Cosmed, Rome, Italy) and estimated by eleven predictive equations. Data were analyzed using Bland-Altman plots, paired t-tests, and Pearson's correlation coefficients. RESULTS: Sixty-two patients were evaluated [50% female; mean age 63.1 ± 5.2 years; diabetes duration of 11 (1-36) years, and mean A1C of 7.6 ± 1.2%]. There was a wide variation in the accuracy of REE values predicted by equations when compared to IC REE measurement. In all patients, Ikeda and Mifflin St-Jeor equations were that most underestimated REE. And, the equations that overestimated the REE were proposed by Dietary Reference Intakes and Huang. The most accurate equations were FAO/WHO/UNO in women (- 1.8% difference) and Oxford in men (- 1.3% difference). CONCLUSION: In patients with type 2 diabetes, in the absence of IC, FAO/WHO/UNO and Oxford equations provide the best REE prediction in comparison to measured REE for women and men, respectively.

Relationship between insulin resistance and adipocytokines: the mediator role of adiposity in children.

Background: Leptin and adiponectin interact with each other in the modulation of obesity and insulin resistance (IR) and it is also important to consider the role of cardiorespiratory and muscular fitness in these relationships.Aim: To analyse the relationship between IR with adipocytokines in children, and to test the mediation effect of %BF (percentage of body fat) in the association of IR with leptin, adiponectin, and L/A ratio.Subjects and methods: This cross-sectional study comprised a sample of 150 schoolchildren, aged 6-11 years, from school in Porto Alegre, Brazil. The following variables were evaluated: cardiorespiratory fitness (CRF), muscular fitness (MF), percentage of body fat (%BF), and biochemical variables (leptin, adiponectin, glucose, and insulin).Results: IR was associated with leptin and L/A ratio, after adjustments for age, sex, sexual maturation, and CRF. When adjusted for age, sex, sexual maturation, and MF, an association was found between IR with leptin and L/A ratio. Moreover, %BF was a mediator in the association between IR and leptin, as well as IR and L/A ratio, explaining 54% and 57% of these associations, respectively.Conclusion: Leptin and L/A ratio are positively associated with IR after adjustments. Also, %BF is a mediator in the associations between IR and leptin and L/A ratio.

Adaptations in mechanical muscle function, muscle morphology, and aerobic power to high-intensity endurance training combined with either traditional or power strength training in older adults: a randomized clinical trial.

PURPOSE: There is a lack of information on the effects of power training (PT) as an alternative to traditional strength training (TST) during concurrent training (CT) in older individuals. This study aimed to verify the neuromuscular adaptations that occurred following 16-week interventions with two CT models in older men: high-intensity interval training (HIIT) combined with either TST or PT. METHODS: Thirty-five older men (65.8 ± 3.9 years) were randomly assigned into one of two training groups CTS: TST + HIIT (n = 18) or CTP: PT + HIIT (n = 17). CTS performed resistance training at intensities ranging from 65 to 80% of 1 RM at slow controlled speed, whereas CTP trained at intensities ranging from 40 to 60% of 1 RM at maximal intentional speed. Lower body one-repetition maximum (1 RM), isometric rate of force development (RFD), countermovement jump (CMJ) muscle power output, quadriceps femoris muscles thickness (QF MT), and peak oxygen uptake (VO2peak) were assessed before training and after 8 and 16 weeks of CT. RESULTS: Groups improved similarly in all primary outcomes (P < 0.05), with mean increases ranging: 1 RM (from 39.4 to 75.8%); RFD (from 9.9 to 64.8%); and CMJ muscle power (from 1.8 to 5.2%). Significant increases (P < 0.05) were observed in all secondary outcomes (QF MT, specific tension and VO2peak) with no differences between groups. CONCLUSION: CT models were effective for improving maximal and explosive force (1 RM, RFD, and CMJ power), QF MT, and VO2peak. Moreover, despite that using lower loading intensities, PT induced similar adaptations to those of TST.

Effects of Traditional and Vascular Restricted Strength Training Program With Equalized Volume on Isometric and Dynamic Strength, Muscle Thickness, Electromyographic Activity, and Endothelial Function Adaptations in Young Adults.

Ramis, TR, Muller, CHdL, Boeno, FP, Teixeira, BC, Rech, A, Pompermayer, MG, Medeiros, NdS, Oliveira, ÁRd, Pinto, RS, and Ribeiro, JL. Effects of traditional and vascular restricted strength training program with equalized volume on isometric and dynamic strength, muscle thickness, electromyographic activity, and endothelial function adaptations in young adults. J Strength Cond Res 34(3): 689-698, 2020-The purpose of the study was to evaluate and compare the acute and chronic effects of partial vascular occlusion training in young, physically active adults. Neuromuscular, morphological, and endothelial function responses were compared between high-intensity resistance training (HI-RT) and low-intensity resistance training with partial vascular occlusion (LI-BFR), despite the same training volume. The 28 subjects (age, 23.96 ± 2.67 years) were randomly assigned into 2 groups: LI-BFR (n = 15) and HI-RT (n = 13). Both groups performed unilateral exercise of elbow flexion (EF) and knee extension (KE) 3 times per week for 8 weeks. This study was approved by the ethics committee. Flow-mediated dilation showed a significant difference in baseline and post-training in the LI-BFR group (4.44 ± 0.51 vs. 6.35 ± 2.08 mm, respectively). For nitrite/nitrate concentrations only, there was a significant difference when comparing pre- and post-acute exercise in both groups. The torque and rep. Sixty percent 1 repetition maximum had improvements in both groups. There were differences between groups only in isometric delta EF and isokinetic delta KE (EF 3.42 ± 5.09 and 9.61 ± 7.52 N·m; KE 12.78 ± 25.61 and 42.69 ± 35.68 N·m; LI-BFR and HI-RT groups, respectively). There was a significant increase of muscle thickness in both groups. An increase of both isokinetic and isometric electromyography (EMG) of biceps of the HI-RT group was observed. The same was observed for the LI-BFR group regarding isokinetic and isometric EMG of vastus lateralis. Thus, in addition to strength and hypertrophy gains, this study also shows benefits related to vascular function. For practical applications, this study demonstrates a clinical importance of LI-BFR training as an alternative methodology.

Effects of a Single Session of High- and Moderate-Intensity Resistance Exercise on Endothelial Function of Middle-Aged Sedentary Men.

Regular resistance exercise is associated with metabolic, neuromuscular and cardiovascular adaptations which improve quality of life and health. However, sedentary subjects have shown acute impairments in endothelial function after high-intensity resistance exercise. The aim of this study was to evaluate endothelial function in sedentary middle-aged men after a single session of resistance exercise at different intensities. Eleven sedentary middle-aged men (40.1 ± 3.9 years; 27.3 ± 1.4 kg/m2) underwent three different conditions of assessment: (1) single knee extension exercise at moderate intensity (MI) [4 sets of 12 repetitions at 50% of one repetition maximum (1RM) for each leg], (2) single knee extension exercise at high intensity (HI) (4 sets of 8 repetitions at 80% of 1RM for each leg), (3) resting for the control condition (CON). Flow-mediated dilation (FMD) was assessed before, 30 and 60 min after exercise. Plasma concentrations of endothelin-1 (ET-1), nitrites and nitrates (NOx) and thiobarbituric acid reactive substances (TBARS) were measured before, immediately after and 60 min after exercise. Blood pressure (BP) was measured prior to the experimental protocols, and in the following times: immediately following, and 2, 5, 10, 15, 30, and 60 min after exertion. There was a significant improvement in FMD 30 min after MI condition (12.5 ± 4.10 vs. 17.2 ± 3.9%; p = 0.016). NOx levels were significantly higher immediately after MI (6.8 ± 3.3 vs. 12.6 ± 4.2 µM; p = 0.007) and there was a significant increase in the concentration of ET-1 immediately after HI (20.02 ± 2.2 vs. 25.4 ± 2.1 pg/mL; p = 0.004). However, there was no significant difference for BP (MI vs. HI) and TBARS among the experimental conditions. Resistance exercise performed at moderate intensity improved vasodilatation via increases on NOx levels and FMD in sedentary middle-aged men.

Acute glycemic responses along 10-week high-intensity training protocols in type 1 diabetes patients.

Glycemic fluctuations were compared throughout 10-week high-intensity training protocols in T1DM patients. Differences were compared using the rate of change in glycaemia during exercise (RoCE). HIIT sessions led to lower RoCE in most weeks than other training protocols. The occurrence of level 1 hypoglycemia along sessions were similar among interventions.

Hypotensive response to continuous aerobic and high-intensity interval exercise matched by volume in sedentary subjects / Resposta hipotensiva ao exercício aeróbio contínuo e intervalado de alta intensidade pareados por volume em indivíduos sedentários

Background: Systemic arterial hypertension (SAH) is one of the main risk factors for heart disease. Among the benefits linked to different modalities of physical exercise, post-exercise hypotension (PEH) is a key point for exercise prescription in this condition. Objective: To investigate and compare PEH in response to continuous aerobic exercise (CONT) and high-intensity interval exercise (HIIE), matched by volume, in sedentary individuals. Methods: A randomized cross-over study, composed of sedentary, healthy male subjects submitted to two acute physical exercise protocols matched by volume, HIIE and CONT, on a treadmill. Hemodynamic measures for the evaluation of PEH were performed pre, immediately after exercise and every five minutes thereafter, during one hour of recovery. Two-way ANOVA with repeated measurements was used for comparisons between groups and Bonferroni post hoc test as appropriate. P < 0.05 was considered significant. Results: Both exercise protocols promoted significant PEH, with reductions in systolic blood pressure (SBP) and mean arterial pressure (MAP). HIIE promoted a reduction of SBP and MAP at the 15th minute, whereas the same effect was observed at the 30th following CONT. Conclusion: Both HIIE and CONT, matched by volume, promote PEH of similar magnitude. However, PEH occurs earlier following HIIE, suggesting a better time /effectiveness ratio, and an additional beneficial effect of this modality

Acute and residual effects of aerobic exercise on fructose-induced postprandial lipemia on lean male subjects.

PURPOSE: The addition of fructose to one or more meals daily may lead to increased postprandial lipemia (PPL). Aerobic exercise has been successful in preventing those increases; however, the duration of exercise effects is still unknown. The aim of this study was to evaluate the acute and residual effects of aerobic exercise and fructose ingestion on PPL. METHODS: Twelve young and sedentary men completed a crossover blinded randomized trial. On day 0, they performed 45 min of aerobic exercise at 60% of VO2peak, or 45 min of resting. On day 1, they received a high-fat meal together with one of the following conditions: (a) a fructose-rich beverage (FRUCT), or (b) exercise performed 13 h before the fructose-rich beverage ingestion (FRUCTEX), or (c) a dextrose-based beverage (DEX). On day 2, all subjects received a high-fat meal plus dextrose. Five blood samples were taken on days 1 and 2, to measure triglycerides (TG), HDL cholesterol, VLDL, total cholesterol (TC), glucose and insulin. RESULTS: On day 1, the delta of the TG peak was higher for FRUCT compared to DEX condition (+ 73.7%; p = 0.019). Total area under the curve (AUC) of TG was lower on the condition FRUCTEX compared to FRUCT (+ 30%; p = 0.001). There was no effect of the beverages or the exercise on VLDL, TC, HDL and non-HDL cholesterol (p > 0.05). There were no differences found in any of the parameters assessed on day 2 (p > 0.05). CONCLUSIONS: Fructose consumption (0.5 g/kg) severely increased postprandial TG on day 1, but not on day 2. Previous exercise performance could lead to ~ 30% reduction on the AUC of postprandial TG in 13 h, but not after 37 h followed by fructose consumption. The regularity of physical exercise practice seems to be essential to promote a constant hypolipemic effect.

Acute effects of strength exercise with blood flow restriction on vascular function of young healthy males.

BACKGROUND: Strength training with blood flow restriction (STBFR) provokes similar neuromuscular adaptations to traditional strength training using low training loads. However, there is a need for better understanding of the repercussions for antioxidant parameters and vascular function. OBJECTIVES: The objective of the present study was to investigate the effects of a session of low intensity strength training with blood flow restriction, compared with high intensity and low intensity strength training without blood flow restriction, on the levels of nitric oxide products and antioxidant enzyme activity in healthy young men. METHODS: Eleven young men performed three strength exercise sessions: low intensity with blood flow restriction (LIBFR), high intensity (HI), and low intensity (LI). Activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) was assessed and metabolites of nitric oxide (NOx) were assayed before and after each session. RESULTS: There were no changes to NOx plasma levels under the different exercise conditions (p > 0.05). However, SOD activity exhibited a significant reduction after the LIBFR condition (p < 0.05), while CAT activity reduced significantly after the LI condition (p < 0.05). CONCLUSIONS: The results of this study suggest that one session of low intensity strength training with blood flow restriction does not reduce bioavailability of nitric oxide or induce redox imbalance in healthy young men.

Effects of dancing compared to walking on cardiovascular risk and functional capacity of older women: A randomized controlled trial.

INTRODUCTION: Aging is characterized by reductions in lean mass simultaneously to increases in visceral adipose tissue, elevating cardiovascular risk (CVR) and physical dependence. Dancing has been recommended for improving fall-risk and CVR, however, comparisons with traditional exercises are limited. This study aimed to compare the effects of dancing with walking on CVR and functionality of older women. METHODS: Thirty sedentary women (65 ±â€¯5 years, BMI 27 ±â€¯4 kg/m2) were randomized into three groups (n = 10/group): dancing, walking or stretching (active control). All interventions lasted 8 weeks (60 min sessions): dancing/walking 3×/week, stretching 1×/week. Dancing: several styles, no partner. Walking: treadmill, 60% peak oxygen consumption (VO2peak). Stretching: large muscle groups, no discomfort. Before and after interventions assessments: VO2peak (primary outcome), total cholesterol, HDL-C, LDL-C, glucose, insulin, CRP, TNF-α, waist and hip circumferences, visceral adipose tissue (VAT), muscle thickness, maximal muscle strength/power, static and dynamic balance, gait ability, flexibility, chair-raise and level of physical activity (PA). STATISTICS: generalized estimating equations, post-hoc LSD (p < 0.05), SPSS 22.0. RESULTS: (Mean-CI): (before vs after): group vs time interaction showed increases in VO2peak (mL·kg-1·min-1) for dancing 23.3 (20.8-25.8) vs 25.6 (23.4-27.8), and walking 23.4 (21.3-25.5) vs 27.0 (25.4-28.6), with no differences for stretching 23.5 (21.3-25.7) vs 23.0 (21.0-24.9). Lower body muscle power and static balance also improved for dancing and walking, but not for stretching. Main time effect showed improvements in CRP, TNF-α, LDL-C, HDL-C, VAT, waist, hip, chair raise, flexibility and level of daily PA for all groups. CONCLUSION: Dancing induced similar increases in VO2peak, lower body muscle power and static balance as walking, while the stretching group remained unchanged. Pooled effects showed improvements in body composition, lipid and inflammatory profile, which are supported by increased PA levels. TRIAL REGISTRATION: NCT03262714.

Functional and physiological adaptations following concurrent training using sets with and without concentric failure in elderly men: A randomized clinical trial.

This study compared the functional and physiological adaptations induced by concurrent training (CT) performed with repetitions to concentric failure and not to failure in elderly men. Fifty-two individuals (66.2 ±â€¯5.2 years) completed the pre- and post-measurements and were divided into three groups: repetitions to failure (RFG, n = 17); repetitions not to failure (NFG, n = 20); and repetitions not to failure with total volume equalized to that in the RFG (ENFG, n = 15). The participants' sit-to-stand ability, timed-up-and-go (TUG), muscle power output in squat jump (SJ) and countermovement jump (CMJ), peak oxygen uptake (VO2peak), blood lipids and glucose, as well as blood pressure levels were assessed. A subsample of our participants (n = 22) also underwent assessment of body composition by dual X-ray absorptiometry (DXA). CT was performed twice weekly for over 12 weeks. In addition to the specific strength training (ST) programme, each group also underwent endurance training (ET) in the same session (i.e., ST immediately followed by ET). After training, all groups improved similarly and significantly in their sit-to-stand ability (P < 0.01), muscle power output relative to body mass in SJ and CMJ (P < 0.001), VO2peak (P < 0.01) and HDL cholesterol levels (P < 0.001). There were reductions in the total, leg and trunk percent fat mass as well as increases in the total, leg and trunk percent lean mass (P values ranging from P < 0.05 to P < 0.01). Independent of performing repetitions until concentric failure and greater ST volumes, all CT groups exhibited improved sit-to-stand ability, muscle power output, VO2peak and HDL cholesterol levels. In addition, our preliminary data suggest that there are no differences in the effects of the assessed CT approaches on body composition outcomes. We therefore highlight the need for additional well-powered studies to assess whether repetitions to failure could underlie distinct effects on body composition.

Cardiorespiratory responses of a dance session designed for older women: A cross sectional study.

BACKGROUND: Dancing has been increasingly used as a type of exercise intervention to improve cardiovascular fitness of older people. However, it is unclear which may be the exercise intensity of the dance sessions. OBJECTIVE: To describe cardiorespiratory responses of a dance session for older women, and to identify intensity zones in relation to peak oxygen consumption (VO2peak), first and second ventilatory thresholds (VT1 and VT2). METHODS: Ten women (66 ±â€¯5 yrs., BMI 27 ±â€¯4) were examined on three occasions: Familiarization, maximum effort and dance sessions. Incremental treadmill test: 5 km/h, 2% slope each min, until maximum effort. Dance class (60 min): warm-up (20 min), across-the-floor (10 min), choreography (15 min), show (10 min) and cool-down (5 min). Ventilatory parameters were measured continuously (breath-by-breath). RESULTS: VO2 (mL·kg-1·min-1): Maximum effort: VO2peak (23.3 ±â€¯4.3), VT1 (17.2 ±â€¯3.5) and VT2 (20.9 ±â€¯3.4). Dancing: warm-up (12.8 ±â€¯2.4, ~55%VO2peak), across-the-floor (14.2 ±â€¯2.4 ~62%VO2peak), choreography (14.6 ±â€¯3.2 ~63%VO2peak) and show (16.1 ±â€¯3.3, ~69% VO2peak). Show was similar to VT1. CONCLUSIONS: Cardiorespiratory demands of a dance class for older women are at low aerobic intensity. Show was similar to VT1, indicating that a dance class may be modulated to improve aerobic fitness, at least at initial stages of training.

Efeito agudo do exercício de força com restrição do fluxo sanguíneo sobre parâmetros antioxidantes em indivíduos jovens saudáveis / Acute effects of strength exercise with blood flow restriction on vascular function of young healthy males

O treinamento de força com restrição do fluxo sanguíneo (TFRFS) promove adaptações neuromusculares semelhantes às do treinamento de força tradicional utilizando pequenas cargas de treinamento. No entanto, sua repercussão sobre parâmetros antioxidantes e sobre a função vascular precisa ser mais bem compreendida. Objetivos: O objetivo do presente estudo foi investigar o efeito de uma sessão de exercício de força de baixa intensidade com restrição do fluxo sanguíneo, em comparação ao exercício de força de alta intensidade e de baixa intensidade sem restrição do fluxo sanguíneo, sobre os níveis de subprodutos do oxido nítrico e a atividade de enzimas antioxidantes em jovens saudáveis. Métodos: Onze indivíduos jovens realizaram três sessões de exercício de força: baixa intensidade com restrição do fluxo sanguíneo (BIRFS), alta intensidade (AI) ou baixa intensidade (BI). Foram avaliadas a atividade das enzimas antioxidantes catalase (CAT), superóxido dismutase (SOD) e dos metabólitos do óxido nítrico (NOx). Resultados: Não houve modificações nos níveis plasmáticos de NOx nas diferentes condições de exercício (p > 0,05). A atividade da SOD apresentou uma diminuição significativa na condição BIRFS (p < 0,05). A atividade da CAT diminuiu significativamente na condição BI (p < 0.05). Conclusões: A partir do presente estudo sugere-se que uma sessão de treinamento de força de baixa intensidade com restrição do fluxo sanguíneo não reduz a biodisponibilidade do óxido nítrico, bem como não induz desequilíbrio redox em indivíduos jovens saudáveis.

Strength training with blood flow restriction (STBFR) provokes similar neuromuscular adaptations to traditional strength training using low training loads. However, there is a need for better understanding of the repercussions for antioxidant parameters and vascular function. Objectives: The objective of the present study was to investigate the effects of a session of low intensity strength training with blood flow restriction, compared with high intensity and low intensity strength training without blood flow restriction, on the levels of nitric oxide products and antioxidant enzyme activity in healthy young men. Methods: Eleven young men performed three strength exercise sessions: low intensity with blood flow restriction (LIBFR), high intensity (HI), and low intensity (LI). Activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) was assessed and metabolites of nitric oxide (NOx) were assayed before and after each session. Results: There were no changes to NOx plasma levels under the different exercise conditions (p > 0.05). However, SOD activity exhibited a significant reduction after the LIBFR condition (p < 0.05), while CAT activity reduced significantly after the LI condition (p < 0.05). Conclusions: The results of this study suggest that one session of low intensity strength training with blood flow restriction does not reduce bioavailability of nitric oxide or induce redox imbalance in healthy young men.

Ingestion of carbohydrate or carbohydrate plus protein does not enhance performance during endurance exercise: a randomized crossover placebo-controlled clinical trial.

A beverage containing protein (PRO) and carbohydrate (CHO) may have an ergogenic effect on endurance performance. However, evidence regarding its efficacy on similar conditions to athletes' race day is still lacking. The objective of this study was to compare the effects of 3 different nutritional supplementation strategies on performance and muscle recovery in a duathlon protocol. Thirteen male athletes (29.7 ± 7.7 years) participated in 3 simulated Olympic-distance duathlon trials (SDTs) under 3 different, randomly assigned supplementation regimens: CHO drink (75 g CHO), isocaloric CHO plus PRO drink (60.5 g CHO and 14.5 g PRO), and placebo drink (PLA). Supplements were offered during the cycling bout. Blood samples were collected before, immediately after, and 24 h after each SDT for creatine kinase (CK) analysis. Isometric peak torque (PT) was measured before and 24 h after each SDT. The primary outcome measure was the time to complete the 5-km running section (t5km) at a self-selected pace. There was no difference in t5km between CHO (1270.3 ± 130.5 s), CHO+PRO (1267.2 ± 138.9 s), and PLA (1275.4 ± 120 s); p = 0.87, effect size (ES) ≤ 0.1. Pre-post changes for PT and CK were not significant for any of the 3 conditions (PT: p = 0.24, ES ≤ 0.4; CK: p = 0.32, ES = 0.3-1.04). For endurance sports lasting up to 2 h, with a pre-exercise meal containing CHO at 1.5 g·kg-1, supplementation with CHO or CHO+PRO does not offer additional benefits for performance and muscle recovery when compared with PLA.

Oxygen desaturation during the six-minute walk test in COPD patients.

OBJECTIVE: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD. METHODS: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope. RESULTS: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = -0.398; p < 0.001), Tmin (r = -0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005). CONCLUSIONS: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

Oxygen desaturation during the six-minute walk test in COPD patients / Análise da dessaturação de oxigênio durante o teste de caminhada de seis minutos em pacientes com DPOC

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD. Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope. Results: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = −0.398; p < 0.001), Tmin (r = −0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005). Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former. .

Objetivo: Avaliar o comportamento da curva de saturação de oxigênio durante o teste de caminhada de seis minutos (TC6) em pacientes com DPOC. Métodos: Incluímos 85 pacientes e todos realizaram espirometria, sendo classificados como portadores de DPOC moderada (DPOCm, n = 30) ou grave (DPOCg, n = 55). Todos os pacientes realizaram TC6 em um corredor de 27 m com monitoramento contínuo da SpO2 e FC por telemetria. A partir das curvas de SpO2, foram analisados os tempos para atingir a queda de 4% da SpO2, para atingir a SpO2 mínima (Tmin) e para a recuperação da SpO2 após o TC6 (TR). Foram calculadas as inclinações dessas curvas. Resultados: A média de idade nos grupos DPOCm e DPOCg foi de 62 ± 11 anos e 66 ± 10 anos, respectivamente. Todos os pacientes iniciaram o teste com SpO2 > 94%, nenhum recebeu suplementação de oxigênio durante o TC6, e não houve interrupções. A distância percorrida no TC6 não apresentou diferença significativa entre os grupos. Os menores valores da SpO2 ocorreram no grupo DPOCg. Não houve diferença no TR entre os grupos, e 71% e 63% dos pacientes nos grupos DPOCg e DPOCm, respectivamente, apresentaram queda de SpO2 ≥ 4% até o primeiro minuto. O VEF1% apresentou correlações significativas com ΔSpO2 (r = −0,398; p < 0,001), Tmin (r = −0,449; p < 0,001) e SpO2 mínima (r = 0,356; p < 0,005). Conclusões: As curvas dos pacientes do grupo DPOCg em relação às do grupo DPOCm apresentaram valores menores de SpO2 e maior Tmin, sugerindo um pior prognóstico nos primeiros. .