-
1.
High-intensity interval exercise lowers postprandial glucose concentrations more in obese adults than lean adults.
Kong, Z, Shi, Q, Sun, S, Tong, TK, Zhang, H, Nie, J
Primary care diabetes. 2019;(6):568-573
Abstract
AIMS: To compare postprandial glucose responses to high-intensity interval exercise (HIE) between obese and lean individuals. METHODS Thirty healthy young adult males (15 obese, 15 lean) ate a standardised meal, then performed HIE (4 × 30-s Wingate cycling/4-min rest) or a no-exercise control trial (CON). Blood glucose was measured preprandially and up to 150 min postprandially. RESULTS Compared to CON, HIE reduced postprandial glucose concentrations at 120-150 min in obese (p < 0.001) and lean men (p < 0.05), with greater reductions in obese than lean subjects at 120 (-27.0% vs. -8.3%), 135 (-31.9% vs. -15.7%), and 150 min (-21.8% vs. -10.6%). The total glucose area under the curve (AUC) for the testing period was lower with HIE than CON among obese men (p < 0.05), but not lean men (p > 0.05). We found moderate correlations between body mass and postprandial glucose changes (r = 0.39-0.44, p < 0.05), and between glucose AUC and body mass and fat free mass (r = 0.39-0.48, p < 0.05). CONCLUSIONS Our findings suggest that HIE may act as a time-efficient lifestyle intervention strategy for improving obesity-related diabetes risk factors, and might play a role in primary diabetes prevention for the healthy but sedentary population.
-
2.
Effects of hydrogen rich water on prolonged intermittent exercise.
Da Ponte, A, Giovanelli, N, Nigris, D, Lazzer, S
The Journal of sports medicine and physical fitness. 2018;(5):612-621
Abstract
BACKGROUND Recent studies showed a positive effect of hydrogen rich water (HRW) intake on acid-base homeostasis at rest. We investigated 2-weeks of HRW intake on repeated sprint performance and acid-base status during prolonged intermittent cycling exercise. METHODS In a cross over single-blind protocol, 8 trained male cyclists (age [mean±SD] 41±7 years, body mass 72.3±4.4 kg, height 1.77±0.04 m, maximal oxygen uptake [V̇O2max] 52.6±4.4 mL·kg-1·min-1) were provided daily with 2 liters of placebo normal water (PLA, pH 7.6, oxidation/reduction potential [ORP] +230 mV, free hydrogen content 0 ppb) or HRW (pH 9.8, ORP -180 mV, free Hydrogen 450 ppb). Tests were performed at baseline and after each period of 2 weeks of treatment. The treatments were counter-balanced and the sequence randomized. The 30-minute intermittent cycling trial consisted in 10 3-minute blocks, each one composed by 90 seconds at 40% V̇O2max, 60 seconds at 60% V̇O2max, 16 seconds all out sprint, and 14 seconds active recovery. Oxygen uptake (V̇O2), heart rate and power output were measured during the whole test, while mean and peak power output (PPO), time to peak power and Fatigue Index (FI) were determined during all the 16 seconds sprints. Lactate, pH and bicarbonate (HCO3-) concentrations were determined at rest and after each sprint on blood obtained by an antecubital vein indwelling catheter. RESULTS In the PLA group, PPO in absolute values decreased significantly at the 8th and 9th of 10 sprints and in relative values, ΔPPO, decreased significantly at 6th, 8th and 9th of 10 sprints (by mean: -12±5%, P<0.006), while it remained unchanged in HRW group. Mean power, FI, time to peak power and total work showed no differences between groups. In both conditions lactate levels increased while pH and HCO3- decreased progressively as a function of the number of sprints. CONCLUSIONS Two weeks of HRW intake may help to maintain PPO in repetitive sprints to exhaustion over 30 minutes.
-
3.
The effects of two different doses of calcium lactate on blood pH, bicarbonate, and repeated high-intensity exercise performance.
Painelli, Vde S, da Silva, RP, de Oliveira, OM, de Oliveira, LF, Benatti, FB, Rabelo, T, Guilherme, JP, Lancha, AH, Artioli, GG
International journal of sport nutrition and exercise metabolism. 2014;(3):286-95
Abstract
We investigated the effects of low- and high-dose calcium lactate supplementation on blood pH and bicarbonate (Study A) and on repeated high-intensity performance (Study B). In Study A, 10 young, physically active men (age: 24 ± 2.5 years; weight: 79.2 ± 9.45 kg; height: 1.79 ± 0.06 m) were assigned to acutely receive three different treatments, in a crossover fashion: high-dose calcium lactate (HD: 300 mg · kg(-1) body mass), low-dose calcium lactate (LD: 150 mg · kg(-1) body mass) and placebo (PL). During each visit, participants received one of these treatments and were assessed for blood pH and bicarbonate 0, 60, 90, 120, 150, 180, and 240 min following ingestion. In Study B, 12 young male participants (age: 26 ± 4.5 years; weight: 82.0 ± 11.0 kg; height: 1.81 ± 0.07 m) received the same treatments of Study A. Ninety minutes after ingestion, participants underwent 3 bouts of the upper-body Wingate test and were assessed for blood pH and bicarbonate 0 and 90 min following ingestion and immediately after exercise. In Study A, both HD and LD promoted slight but significant increases in blood bicarbonate (31.47 ± 1.57 and 31.69 ± 1.04 mmol · L(-1, respectively) and pH levels (7.36 ± 0.02 and 7.36 ± 0.01, respectively), with no effect of PL. In Study B, total work done, peak power, mean power output were not affected by treatments. In conclusion, low- and high-dose calcium lactate supplementation induced similar, yet very discrete, increases in blood pH and bicarbonate, which were not sufficiently large to improve repeated high-intensity performance.
-
4.
Effect of sodium bicarbonate and Beta-alanine on repeated sprints during intermittent exercise performed in hypoxia.
Saunders, B, Sale, C, Harris, RC, Sunderland, C
International journal of sport nutrition and exercise metabolism. 2014;(2):196-205
Abstract
PURPOSE To investigate the separate and combined effects of sodium bicarbonate and beta-alanine supplementation on repeated sprints during simulated match play performed in hypoxia. METHODS Study A: 20 recreationally active participants performed two trials following acute supplementation with either sodium bicarbonate (0.3 g·kg-1BM) or placebo (maltodextrin). Study B: 16 recreationally active participants were supplemented with either a placebo or beta-alanine for 5 weeks (6.4 g·day-1 for 4 weeks, 3.2 g·day-1 for 1 week), and performed one trial before supplementation (with maltodextrin) and two following supplementation (with sodium bicarbonate and maltodextrin). Trials consisted of 3 sets of 5 × 6 s repeated sprints performed during a football specific intermittent treadmill protocol performed in hypoxia (15.5% O2). Mean (MPO) and peak (PPO) power output were recorded as the performance measures. RESULTS Study A: Overall MPO was lower with sodium bicarbonate than placebo (p = .02, 539.4 ± 84.5 vs. 554.0 ± 84.6 W), although there was no effect across sets (all p > .05). Study B: There was no effect of beta-alanine, or cosupplementation with sodium bicarbonate, on either parameter, although there was a trend toward higher MPO with sodium bicarbonate (p = .07). CONCLUSIONS The effect of sodium bicarbonate on repeated sprints was equivocal, although there was no effect of beta-alanine or cosupplementation with sodium bicarbonate. Individual variation may have contributed to differences in results with sodium bicarbonate, although the lack of an effect with beta-alanine suggests this type of exercise may not be influenced by increased buffering capacity.
-
5.
Effects of caffeine on session ratings of perceived exertion.
Killen, LG, Green, JM, O'Neal, EK, McIntosh, JR, Hornsby, J, Coates, TE
European journal of applied physiology. 2013;(3):721-7
Abstract
This study examined effects of caffeine on session ratings of perceived exertion (RPE) following 30 min constant-load cycling. Individuals (n = 15) of varying aerobic fitness completed a [Formula: see text] max trial and two 30 min cycling bouts (double-blind, counterbalanced) following ingestion of 6 mL/kg of caffeine or matched placebo. RPE overall, legs and breathing were estimated every 5 min and session RPE was estimated 30 min post-exercise using the OMNI pictorial scale. Session RPE for caffeine and placebo trails were compared using paired t test. Between-trial comparisons of HR, RPE overall, RPE legs and RPE breathing were analyzed using an independent 2 (trial) × 6 (time point) repeated measures analysis of variance (ANOVA) for each dependent variable. Caffeine resulted in a significantly lower session RPE (p < 0.05) for caffeine (6.1 ± 2.2) versus placebo (6.8 ± 2.1). Acute perceptual responses were significantly lower for caffeine for RPE overall (15, 20, 25, and 30 min), RPE breathing (15, 20, 25, and 30 min) and RPE legs (20 and 30 min). Survey responses post-exercise revealed greater feelings of nervousness, tremors, restlessness and stomach distress following caffeine versus placebo. Blunted acute RPE and survey responses suggest participants responded to caffeine ingestion. Caffeine decreased acute RPE during exercise which could partially account for lower session RPE responses. However, decreased session RPE could also reveal a latent analgesic affect of caffeine extending into recovery. Extending the understanding of session RPE could benefit coaches in avoiding overtraining when adjusting training programs.
-
6.
Effect of caffeine on RPE and perceptions of pain, arousal, and pleasure/displeasure during a cycling time trial in endurance trained and active men.
Astorino, TA, Cottrell, T, Talhami Lozano, A, Aburto-Pratt, K, Duhon, J
Physiology & behavior. 2012;(2):211-7
Abstract
Caffeine has been reported to alter perceptions of exertion, muscle pain, and mood, yet the majority of existing data were obtained in resting volunteers or during steady-state exercise. The primary aim of this study was to examine the effects of caffeine on rating of perceived exertion (RPE) and perceptions of leg pain, arousal, and pleasure/displeasure during a simulated cycling time trial. Endurance-trained (n=8, VO(2)max=57.5±3.9 mL/kg/min) and active (n=8, VO(2)max=46.5±6.3 mL/kg/min) men initially completed two familiarization trials separated by at least 48 h. Over the next three trials, they completed a 10 km time trial preceded by ingestion of drinks containing caffeine (5 mg/kg ingested on 2 separate days) or placebo. Treatments were ingested using a single-blind, crossover design, and participants were deceived as to the content of all drinks. During exercise, RPE (6-20 scale), leg pain (0-10 scale), arousal (Felt Arousal Scale), and pleasure/displeasure (Feeling Scale) were recorded using various categorical scales. Repeated measures analysis of variance was used to assess differences in all variables across time and treatments, with fitness level used as a between-subjects variable. Pleasure/displeasure was altered (p<0.05, partial eta-squared (η(2))=0.23) with caffeine compared to placebo, although leg pain, RPE, and arousal were similar (p>0.05) across treatments. Caffeine increased (p<0.05, η(2)=0.27) cycling performance by 0.3-2.0% versus placebo, with no effect (p>0.05) of fitness level. Only in trained men; however, was there a significant caffeine-mediated improvement in cycling performance, which was consequent with diminished mood in trained and improved mood in active individuals.
-
7.
Acute effects of aerobic exercise on mood and hunger feelings in male obese adolescents: a crossover study.
Lofrano-Prado, MC, Hill, JO, Silva, HJ, Freitas, CR, Lopes-de-Souza, S, Lins, TA, do Prado, WL
The international journal of behavioral nutrition and physical activity. 2012;:38
Abstract
BACKGROUND The aim of this study was to determine the acute effects of exercise intensity on anxiety, mood states and hunger in obese adolescents. METHODS Subjects were eight male obese adolescents (age 15.44 ± 2.06 y; BMI 33.06 ± 4.78 kg/m2). Each subject underwent three experimental trials: (1) Control, seated for 30 min; (2) Low intensity exercise (LIE)--exercise at 10% below ventilatory threshold (VT); (3) High intensity exercise (HIE)--exercise at 10% above VT. Anxiety (STAI Trait/State), mood (POMS) and hunger (VAS) were assessed before and immediately after the experimental sessions. Comparisons between trials and times were assessed using Kruskal-Wallis and Wilcoxon tests, respectively. Associations between variables were described using a Spearman test. RESULTS The largest increase in hunger was observed after LEI (914.22%). Both exercise sessions increased anxiety, fatigue and decreased vigor (p < 0.05). CONCLUSIONS Acute exercise bouts are associated with negative changes in anxiety and mood, and with increases in hunger in obese adolescents.
-
8.
Effects of caffeine, sodium bicarbonate, and their combined ingestion on high-intensity cycling performance.
Kilding, AE, Overton, C, Gleave, J
International journal of sport nutrition and exercise metabolism. 2012;(3):175-83
Abstract
PURPOSE To determine the effects of ingesting caffeine (CAFF) and sodium bicarbonate (SB), taken individually and simultaneously, on 3-km cycling time-trial (TT) performance. METHOD Ten well-trained cyclists, age 24.2 ± 5.4 yr, participated in this acute-treatment, double-blind, crossover study that involved four 3-km cycling TTs performed on separate days. Before each TT, participants ingested either 3 mg/kg body mass (BM) of CAFF, 0.3 g · kg⁻¹ · BM⁻¹ of SB, a combination of the two (CAFF+SB), or a placebo (PLAC). They completed each 3-km TT on a laboratory-based cycle ergometer, during which physiological, perceptual, and performance measurements were determined. For statistical analysis, the minimal worthwhile difference was considered ~1% based on previous research. RESULTS Pretrial pH and HCO₃ were higher in SB and CAFF+SB than in the CAFF and PLAC trials. Differences across treatments for perceived exertion and gastric discomfort were mostly unclear. Compared with PLAC, mean power output during the 3-km TT was higher in CAFF, SB, and CAFF+SB trials (2.4%, 2.6%, 2.7% respectively), resulting in faster performance times (-0.9, -1.2, -1.2% respectively). Effect sizes for all trials were small (0.21-0.24). CONCLUSIONS When ingested individually, both CAFF and SB enhance high-intensity cycling TT performance in trained cyclists. However, the ergogenic effect of these 2 popular supplements was not additive, bringing into question the efficacy of coingesting the 2 supplements before short-duration high-intensity exercise. In this study there were no negative effects of combining CAFF and SB, 2 relatively inexpensive and safe supplements.
-
9.
Maximal and submaximal physiological responses to adaptation to deep water running.
Azevedo, LB, Lambert, MI, Zogaib, PS, Barros Neto, TL
Journal of sports sciences. 2010;(4):407-14
-
-
Free full text
-
Abstract
The aim of the study was to compare physiological responses between runners adapted and not adapted to deep water running at maximal intensity and the intensity equivalent to the ventilatory threshold. Seventeen runners, either adapted (n = 10) or not adapted (n = 7) to deep water running, participated in the study. Participants in both groups undertook a maximal treadmill running and deep water running graded exercise test in which cardiorespiratory variables were measured. Interactions between adaptation (adapted vs. non-adapted) and condition (treadmill running vs. deep water running) were analysed. The main effects of adaptation and condition were also analysed in isolation. Runners adapted to deep water running experienced less of a reduction in maximum oxygen consumption (VO2max) in deep water running compared with treadmill running than runners not adapted to deep water running. Maximal oxygen consumption, maximal heart rate, maximal ventilation, VO2max at the ventilatory threshold, heart rate at the ventilatory threshold, and ventilation at the ventilatory threshold were significantly higher during treadmill than deep water running. Therefore, we conclude that adaptation to deep water running reduces the difference in VO2max between the two modalities, possibly due to an increase in muscle recruitment. The results of this study support previous findings of a lower maximal and submaximal physiological response on deep water running for most of the measured parameters.
-
10.
The effect of whole-body cryostimulation on lysosomal enzyme activity in kayakers during training.
Wozniak, A, Wozniak, B, Drewa, G, Mila-Kierzenkowska, C, Rakowski, A
European journal of applied physiology. 2007;(2):137-42
Abstract
Effects of whole-body cryostimulation on lysosomal enzyme activity: acid phosphatase (AcP), arylsulphatase (ASA) and cathepsin D (CTS D), as well as on the creatine kinase (CK), and the cortisol concentration in the serum of kayakers during training were studied. Additionally, the effect of a single cryostimulation treatment in untrained men was evaluated. The kayakers were subjected to a ten-day training cycle, in which training sessions were preceded by whole-body cryostimulation at a temperature ranging from -120 to -140 degrees C, and to a control training without cryostimulation. Blood samples were taken from the kayakers before the training and after the sixth and tenth day of training and from untrained men before and after cryostimulation. The single cryostimulation caused a 30% (P < 0.05) decrease in the CK activity in untrained men. After the sixth day of training with cryostimulation, the activity of ASA was 46% (P < 0.001), AcP 32% (P < 0.05) and CK 34% lower (P < 0.05) than after the sixth day of training without cryostimulation. The results support that preceding training with whole-body cryostimulation alleviates exertion stress by a stabilisation of lysosomal membranes.