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1.
Olav Vikmoen Truls Raastad Olivier Seynnes Kristoffer Bergstr?m Stian Ellefsen Bent R. R?nnestad 《PloS one》2016,11(3)
Purpose
The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes. We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors.Methods
Nineteen female endurance athletes [maximal oxygen consumption (VO2max): 53±3 ml∙kg-1∙min-1, 5.8 h weekly endurance training] were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four leg exercises [3 x 4–10 repetition maximum (RM)], twice a week for 11 weeks. Muscle strength, 40 min all-out running distance, running performance determinants and patellar tendon stiffness were measured before and after the intervention.Results
E+S increased 1RM in leg exercises (40 ± 15%) and maximal jumping height in counter movement jump (6 ± 6%) and squat jump (9 ± 7%, p < 0.05). This was accompanied by increased muscle fiber cross sectional area of both fiber type I (13 ± 7%) and fiber type II (31 ± 20%) in m. vastus lateralis (p < 0.05), with no change in capillary density in m. vastus lateralis or the stiffness of the patellar tendon. Neither E+S nor E changed running economy, fractional utilization of VO2max or VO2max. There were also no change in running distance during a 40 min all-out running test in neither of the groups.Conclusion
Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only. 相似文献2.
Bradley Clark Vitor P. Costa Brendan J. O'Brien Luiz G. Guglielmo Carl D. Paton 《PloS one》2014,9(12)
Objectives
Competitive endurance athletes commonly undertake periods of overload training in the weeks prior to major competitions. This investigation examined the effects of two seven-day high-intensity overload training regimes (HIT) on performance and physiological characteristics of competitive cyclists.Design
The study was a matched groups, controlled trial.Methods
Twenty-eight male cyclists (mean ± SD, Age: 33±10 years, Mass 74±7 kg, VO2 peak 4.7±0.5 L·min−1) were assigned to a control group or one of two training groups for seven consecutive days of HIT. Before and after training cyclists completed an ergometer based incremental exercise test and a 20-km time-trial. The HIT sessions were ∼120 minutes in duration and consisted of matched volumes of 5, 10 and 20 second (short) or 15, 30 and 45 second (long) maximal intensity efforts.Results
Both the short and long HIT regimes led to significant (p<0.05) gains in time trial performance compared to the control group. Relative to the control group, the mean changes (±90% confidence limits) in time-trial power were 8.2%±3.8% and 10.4%±4.3% for the short and long HIT regimes respectively; corresponding increases in peak power in the incremental test were 5.5%±2.7% and 9.5%±2.5%. Both HIT (short vs long) interventions led to non-significant (p>0.05) increases (mean ± SD) in VO2 peak (2.3%±4.7% vs 3.5%±6.2%), lactate threshold power (3.6%±3.5% vs 2.9%±5.3%) and gross efficiency (3.2%±2.4% vs 5.1%±3.9%) with only small differences between HIT regimes.Conclusions
Seven days of overload HIT induces substantial enhancements in time-trial performance despite non-significant increases in physiological measures with competitive cyclists. 相似文献3.
Allan Inoue Franco M. Impellizzeri Flávio O. Pires Fernando A. M. S. Pompeu Andrea C. Deslandes Tony M. Santos 《PloS one》2016,11(1)
Objectives
The current study compared the effects of high-intensity aerobic training (HIT) and sprint interval training (SIT) on mountain biking (MTB) race simulation performance and physiological variables, including peak power output (PPO), lactate threshold (LT) and onset of blood lactate accumulation (OBLA).Methods
Sixteen mountain bikers (mean ± SD: age 32.1 ± 6.4 yr, body mass 69.2 ± 5.3 kg and VO2max 63.4 ± 4.5 mL∙kg-1∙min-1) completed graded exercise and MTB performance tests before and after six weeks of training. The HIT (7–10 x [4–6 min—highest sustainable intensity / 4–6 min—CR100 10–15]) and SIT (8–12 x [30 s—all-out intensity / 4 min—CR100 10–15]) protocols were included in the participants’ regular training programs three times per week.Results
Post-training analysis showed no significant differences between training modalities (HIT vs. SIT) in body mass, PPO, LT or OBLA (p = 0.30 to 0.94). The Cohen’s d effect size (ES) showed trivial to small effects on group factor (p = 0.00 to 0.56). The interaction between MTB race time and training modality was almost significant (p = 0.08), with a smaller ES in HIT vs. SIT training (ES = -0.43). A time main effect (pre- vs. post-phases) was observed in MTB race performance and in several physiological variables (p = 0.001 to 0.046). Co-variance analysis revealed that the HIT (p = 0.043) group had significantly better MTB race performance measures than the SIT group. Furthermore, magnitude-based inferences showed HIT to be of likely greater benefit (83.5%) with a lower probability of harmful effects (0.8%) compared to SIT.Conclusion
The results of the current study suggest that six weeks of either HIT or SIT may be effective at increasing MTB race performance; however, HIT may be a preferable strategy.Trial Registration
ClinicalTrials.gov NCT01944865相似文献4.
Yuqin Shen Haoming Song Wenlin Ma Zhu Gong Yi Ni Xiaoyu Zhang Wenjun Xu Jinfa Jiang Lin Che Jiahong Xu Wenwen Yan Lin Zhou Guanghe Li Qiping Zhang Lemin Wang 《PloS one》2016,11(1)
Background
Cardiopulmonary exercise testing has been widely used to risk stratify patients with chronic heart failure (CHF). Peak oxygen consumption (peakVO2) was regarded as a powerful predictor of survival, as it is a surrogate for peak cardiac output (CO), which by most is considered the “true” measure of heart failure. Therefore, it is reasonable to hypothesize that CO is an even stronger predictor than peak VO2. The present study is aimed to investigate the prognostic value of peak cardiac power output (peak CPO) in comparison with peakVO2 in Chinese patients with CHF.Methods
Participants provided written informed consent to participate in this study. Totally 129 patients with CHF underwent symptom-limited cardiopulmonary exercise testing (CPET), with mean age 59.1±11.4 years, 87.6% male, 57.4% ischemic etiology, body mass index (BMI) 24.7±3.7 kg/m2 and LVEF 38±9%. CO was measured using an inert gas rebreathing method. The primary endpoints are cardiac deaths.Results
Over median 33.7-month follow-up, 19 cardiac deaths were reported. Among peak VO2,VE/VCO2 slope and Peak CPO, their area under ROC were 0.64, 0.67, 0.68, respectively (Ρ<0.05).The optimal thresholds for predicting cardiac deaths were peak VO2≤13.4 ml.kg-1.min-1, and VE/VCO2 slope≥39.3 and peak CPO≤ 1.1 respectively by ROC analysis. Finally, in patients with a peak VO2≤13.4 ml.kg-1.min-1 those with peak CPO>1.1W had better survival than those with peak CPO ≤ 1.1W. However, by multivariate analysis adjusted for age, sex, BMI, resting heart rate, LVMI, LVEF, Peak CPO was not an independent predictor of cardiac deaths (P> 0.05).Conclusions
Peak CPO was not a predictor of cardiac death in Chinese CHF patients. 相似文献5.
6.
Introduction
People with Peripheral Neuropathy (PN), especially those with impaired sensory inputs through the small-afferent fiber (type II afferent fibers) reflex loop (SAF), might depend more on the large-afferent fiber (type I afferent fibers) reflex loop (LAF) for postural control.Purpose
To examine whether the function of the LAF reflex loop, reflected by the H-reflex and ankle joint proprioception, influences postural control when the SAF reflex loop is impaired, as indicated by reduced foot sole cutaneous sensation.Methods
Thirteen participants (8 women, 5 men) diagnosed with PN and 12 age-matched controls (7 women, 5 men) completed the testing protocol. Measures of interest included the H-index, active (AAP) and passive (PAP) ankle proprioception, plantar pressure sensitivity (PPS), average sway velocity (VAVG) and area (A95) during 30 seconds eyes-closed standing, 6-minute walk distance (6MWD) and timed up-and-go duration (TUG).Results
Statistically significant group-dependent regression was observed between VAVG and H-index. Compared to the control group, the PN group demonstrated reduced PPS (2.0 ± 1.9 vs. 4.2 ± 1.2, P < .05) and H-index (63.6 ± 10.9 vs. 76.4 ± 16.0, P < .05), greater VAVG (3.5 ± 2.1 vs. 1.6 ± 0.6cm/s, P < .05) and A95 (10.0 ± 10.1 vs. 2.5 ± 1.5cm2, P < .05), shorter 6MWD (442.2 ± 93.0 vs. 525.3 ± 68.2m, P < .05), and longer TUG (9.4 ± 1.6 vs. 6.5 ± 1.3s, P < .05). Within the PN group, but not the control group, the H-index was correlated with VAVG (r = -.56, P < .05). Moreover, within the PN group only, PAP scores were correlated with 6MWD (r = -.68, P < .05) and TUG (r = -.59, P < .05) performance. No other statistically significant group difference, correlation or group-dependent regression was observed.Conclusion
VAVG, 6MWD, and TUG correlated with LAF reflex loop function observed among those with impaired functioning of the SAF reflex loop. This observation suggests that the LAF reflex loop may be critical to the control of balance in those individuals suffering from small-fiber PN. 相似文献7.
Clinical characteristics of OGTT-derived hepatic- and muscle insulin resistance in healthy young men
Maeng Kyu Kim 《Journal of Exercise Nutrition & Biochemistry》2014,18(4):385-392
[Purpose]
Insulin inhibits glucose release in the liver but increases glucose absorption in muscles. When insulin cannot properly control glucose, it negatively affects glucose metabolism and, furthermore, contributes to the onset of metabolic syndrome and chronic disease. Therefore, this study''s goal is to understand the clinical characteristics of hepatic insulin resistance and muscle insulin sensitivity in healthy young men.[Methods]
Twenty-eight healthy young men (age 23.3 ± 0.5; mean ± SE) participated in this study. Liver function and blood lipids were measured by blood sampling from brachial vein after participants fasted the previous day. Hepatic insulin resistance and muscle insulin sensitivity were evaluated using two-hour OGTT along with surrogate index related to insulin sensitivity. The VO2max was evaluated using cycle ergometer. Systemic insulin sensitivity was evaluated using two-hour euglycemic hyperinsulinemic clamp method.[Results]
Hepatic insulin resistance showed a significant correlation with body fat (r = 0.609, p < 0.05). Also, hepatic insulin resistance showed a significant correlation with GOT (r = 0.467), GPT (r = 0.434), and γ-GTP (r = 0.375), reflecting liver functions, as well as showing a significant correlation with hs-CRP (r = 0.492, p < 0.05). On the other hand, muscle insulin sensitivity had no correlation with neither body fat nor liver function index (p > 0.05), and among surrogate indexes, it showed a significant correlation with Avignon (r = -0.493) and Matsuda index (r = -0.577). Glucose infusion rate, using the clamp method, showed a significant correlation with muscle insulin sensitivity (r = 0.448, p < 0.05). The VO2max had a significant correlation with hepatic insulin resistance (r = -0.435, p < 0.05) and muscle insulin sensitivity (r = 0.474, p < 0.05), respectively.[Conclusion]
For young men in their 20''s, the OGTT-based hepatic insulin sensitivity was an indicator of hepatic function and body fat but muscle insulin sensitivity was related to peripheral insulin sensitivity. Also, for young men, higher VO2max indicated lower hepatic insulin resistance and higher muscle insulin sensitivity. 相似文献8.
Objective
To describe different end criteria for reaching maximal oxygen uptake (VO2max) during a continuous graded exercise test on the treadmill, and to explore the manner by which different end criteria have an impact on the magnitude of the VO2max result.Methods
A sample of 861 individuals (390 women) aged 20–85 years performed an exercise test on a treadmill until exhaustion. Gas exchange, heart rate, blood lactate concentration and Borg Scale6–20 rating were measured, and the impact of different end criteria on VO2max was studied;VO2 leveling off, maximal heart rate (HRmax), different levels of respiratory exchange ratio (RER), and postexercise blood lactate concentration.Results
Eight hundred and four healthy participants (93%) fulfilled the exercise test until voluntary exhaustion. There were no sex-related differences in HRmax, RER, or Borg Scale rating, whereas blood lactate concentration was 18% lower in women (P<0.001). Forty-two percent of the participants achieved a plateau in VO2; these individuals had 5% higher ventilation (P = 0.033), 4% higher RER (P<0.001), and 5% higher blood lactate concentration (P = 0.047) compared with participants who did not reach a VO2 plateau. When using RER ≥1.15 or blood lactate concentration ≥8.0 mmol•L–1, VO2max was 4% (P = 0.012) and 10% greater (P<0.001), respectively. A blood lactate concentration ≥8.0 mmol•L–1 excluded 63% of the participants in the 50–85-year-old cohort.Conclusions
A range of typical end criteria are presented in a random sample of subjects aged 20–85 years. The choice of end criteria will have an impact on the number of the participants as well as the VO2max outcome. Suggestions for new recommendations are given. 相似文献9.
Nathalie M. M. Benda Joost P. H. Seeger Guus G. C. F. Stevens Bregina T. P. Hijmans-Kersten Arie P. J. van Dijk Louise Bellersen Evert J. P. Lamfers Maria T. E. Hopman Dick H. J. Thijssen 《PloS one》2015,10(10)
Introduction
Physical fitness is an important prognostic factor in heart failure (HF). To improve fitness, different types of exercise have been explored, with recent focus on high-intensity interval training (HIT). We comprehensively compared effects of HIT versus continuous training (CT) in HF patients NYHA II-III on physical fitness, cardiovascular function and structure, and quality of life, and hypothesize that HIT leads to superior improvements compared to CT.Methods
Twenty HF patients (male:female 19:1, 64±8 yrs, ejection fraction 38±6%) were allocated to 12-weeks of HIT (10*1-minute at 90% maximal workload—alternated by 2.5 minutes at 30% maximal workload) or CT (30 minutes at 60–75% of maximal workload). Before and after intervention, we examined physical fitness (incremental cycling test), cardiac function and structure (echocardiography), vascular function and structure (ultrasound) and quality of life (SF-36, Minnesota living with HF questionnaire (MLHFQ)).Results
Training improved maximal workload, peak oxygen uptake (VO2peak) related to the predicted VO2peak, oxygen uptake at the anaerobic threshold, and maximal oxygen pulse (all P<0.05), whilst no differences were present between HIT and CT (N.S.). We found no major changes in resting cardiovascular function and structure. SF-36 physical function score improved after training (P<0.05), whilst SF-36 total score and MLHFQ did not change after training (N.S.).Conclusion
Training induced significant improvements in parameters of physical fitness, although no evidence for superiority of HIT over CT was demonstrated. No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III.Trial Registration
Nederlands Trial Register NTR3671 相似文献10.
Katrina J. Curtis Katie A. O’Brien Rebecca J. Tanner Juliet I. Polkey Magdalena Minnion Martin Feelisch Michael I. Polkey Lindsay M. Edwards Nicholas S. Hopkinson 《PloS one》2015,10(12)
Background
Dietary nitrate supplementation can enhance exercise performance in healthy people, but it is not clear if it is beneficial in COPD. We investigated the hypotheses that acute nitrate dosing would improve exercise performance and reduce the oxygen cost of submaximal exercise in people with COPD.Methods
We performed a double-blind, placebo-controlled, cross-over single dose study. Subjects were randomised to consume either nitrate-rich beetroot juice (containing 12.9mmoles nitrate) or placebo (nitrate-depleted beetroot juice) 3 hours prior to endurance cycle ergometry, performed at 70% of maximal workload assessed by a prior incremental exercise test. After a minimum washout period of 7 days the protocol was repeated with the crossover beverage.Results
21 subjects successfully completed the study (age 68±7years; BMI 25.2±5.5kg/m2; FEV1 percentage predicted 50.1±21.6%; peak VO2 18.0±5.9ml/min/kg). Resting diastolic blood pressure fell significantly with nitrate supplementation compared to placebo (-7±8mmHg nitrate vs. -1±8mmHg placebo; p = 0.008). Median endurance time did not differ significantly; nitrate 5.65 (3.90–10.40) minutes vs. placebo 6.40 (4.01–9.67) minutes (p = 0.50). However, isotime oxygen consumption (VO2) was lower following nitrate supplementation (16.6±6.0ml/min/kg nitrate vs. 17.2±6.0ml/min/kg placebo; p = 0.043), and consequently nitrate supplementation caused a significant lowering of the amplitude of the VO2-percentage isotime curve.Conclusions
Acute administration of oral nitrate did not enhance endurance exercise performance; however the observation that beetroot juice caused reduced oxygen consumption at isotime suggests that further investigation of this treatment approach is warranted, perhaps targeting a more hypoxic phenotype.Trial Registration
ISRCTN Registry ISRCTN66099139 相似文献11.
Francesco De Cobelli Giulio Pezzetti Sergio Margari Antonio Esposito Francesco Giganti Giulia Agostini Alessandro Del Maschio 《PloS one》2015,10(4)
Introduction
Abdominal pain in PNH has never been investigated by in-vivo imaging studies. With MRI, we aimed to assess mesenteric vessels flow and small bowel wall perfusion to investigate the ischemic origin of abdominal pain.Materials and Methods
Six PNH patients with (AP) and six without (NOP) abdominal pain underwent MRI. In a blinded fashion, mean flow (MF, quantity of blood moving through a vessel within a second, in mL·s-1) and stroke volume (SV, volume of blood pumped out at each heart contraction, in mL) of Superior Mesenteric Vein (SMV) and Artery (SMA), areas under the curve at 60 (AUC60) and 90 seconds (AUC90) and Ktrans were assessed by two operators.Results
Mean total perfusion and flow parameters were lower in AP than in NOP group. AUC60: 84.81 ± 11.75 vs. 131.73 ± 18.89 (P < 0.001); AUC90: 102.33 ± 14.16 vs. 152.58 ± 22.70 (P < 0.001); Ktrans: 0.0346 min-1 ± 0.0019 vs. 0.0521 ± 0.0015 (P = 0.093 duodenum, 0.009 jejunum/ileum). SMV: MF 4.67 ml/s ± 0.85 vs. 8.32 ± 2.14 (P = 0.002); SV 3.85 ml ± 0.76 vs. 6.55 ± 1.57 (P = 0.02). SMA: MF 6.95 ± 2.61 vs. 11.2 ± 2.32 (P = 0.07); SV 6.52 ± 2.19 vs. 8.78 ± 1.63 (P = 0.07). We found a significant correlation between MF and SV of SMV and AUC60 (MF:ρ = 0.88, P < 0.001; SV: ρ = 0.644, P = 0.024), AUC90 (MF: ρ = 0.874, P < 0.001; SV:ρ = 0.774, P = 0.003) and Ktrans (MF:ρ = 0.734, P = 0.007; SV:ρ = 0.581, P = 0.047).Conclusions
Perfusion and flow MRI findings suggest that the impairment of small bowel blood supply is significantly associated with abdominal pain in PNH. 相似文献12.
Bart B. L. Groen Astrid M. Horstman Henrike M. Hamer Michiel de Haan Janneau van Kranenburg J?rgen Bierau Martijn Poeze Will K. W. H. Wodzig Blake B. Rasmussen Luc J. C. van Loon 《PloS one》2015,10(11)
Background
Protein turnover in skeletal muscle tissue is highly responsive to nutrient intake in healthy adults.Objective
To provide a comprehensive overview of post-prandial protein handling, ranging from dietary protein digestion and amino acid absorption, the uptake of dietary protein derived amino acids over the leg, the post-prandial stimulation of muscle protein synthesis rates, to the incorporation of dietary protein derived amino acids in de novo muscle protein.Design
12 healthy young males ingested 20 g intrinsically [1-13C]-phenylalanine labeled protein. In addition, primed continuous L-[ring-2H5]-phenylalanine, L-[ring-2H2]-tyrosine, and L-[1-13C]-leucine infusions were applied, with frequent collection of arterial and venous blood samples, and muscle biopsies throughout a 5 h post-prandial period. Dietary protein digestion, amino acid absorption, splanchnic amino acid extraction, amino acid uptake over the leg, and subsequent muscle protein synthesis were measured within a single in vivo human experiment.Results
55.3±2.7% of the protein-derived phenylalanine was released in the circulation during the 5 h post-prandial period. The post-prandial rise in plasma essential amino acid availability improved leg muscle protein balance (from -291±72 to 103±66 μM·min-1·100 mL leg volume-1; P<0.001). Muscle protein synthesis rates increased significantly following protein ingestion (0.029±0.002 vs 0.044±0.004%·h-1 based upon the muscle protein bound L-[ring-2H5]-phenylalanine enrichments (P<0.01)), with substantial incorporation of dietary protein derived L-[1-13C]-phenylalanine into de novo muscle protein (from 0 to 0.0201±0.0025 MPE).Conclusion
Ingestion of a single meal-like amount of protein allows ~55% of the protein derived amino acids to become available in the circulation, thereby improving whole-body and leg protein balance. About 20% of the dietary protein derived amino acids released in the circulation are taken up in skeletal muscle tissue following protein ingestion, thereby stimulating muscle protein synthesis rates and providing precursors for de novo muscle protein synthesis.Trial Registration
trialregister.nl 3638 相似文献13.
Hai-Jeon Yoon Han-Na Kim Yeojun Yun Yemi Kim Ae-Na Ha Hyung-Lae Kim Bom Sahn Kim 《PloS one》2015,10(11)
Background
This study investigated the relationships between background intestinal uptake on 18F–FDG PET and cardio-metabolic risk (CMR) factors.Methods
A total of 326 female patients that underwent 18F–FDG PET to determine the initial stage of breast cancer were enrolled. None of the patients had history of diabetes or hypertension. The background intestinal uptake on PET was visually graded (low vs. high uptake group) and quantitatively measured using the maximal standardized uptake value (SUVmax). SUVmax of 7 bowel segments (duodenum, jejunum, ileum, cecum, hepatic flexure, splenic flexure, and descending colon-sigmoid junction) were averaged for the total bowel (TB SUVmax). Age, body mass index (BMI), fasting blood glucose level (BST), triglyceride (TG), cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL) were the considered CMR factors. The relationships between background intestinal 18F–FDG uptake on PET and diverse CMR factors were analyzed.Results
The visual grades based on background intestinal 18F–FDG uptake classified 100 (30.7%) patients into the low uptake group, while 226 (69.3%) were classified into the high uptake group. Among CMR factors, age (p = 0.004), BMI (p<0.001), and TG (p<0.001) were significantly different according to visual grade of background intestinal 18F–FDG uptake. Quantitative TB SUVmax showed significant positive correlation with age (r = 0.203, p<0.001), BMI (r = 0.373, p<0.001), TG (r = 0.338, p<0.001), cholesterol (r = 0.148, p = 0.008), and LDL (r = 0.143, p = 0.024) and significant negative correlation with HDL (r = -0.147, p = 0.022). Multivariate analysis indicated that BMI and TG were independent factors in both visually graded background intestinal 18F–FDG uptake (p = 0.027 and p = 0.023, respectively) and quantitatively measured TB SUVmax (p = 0.006 and p = 0.004, respectively).Conclusion
Increased background intestinal 18F–FDG uptake on PET may suggest alteration of lipid metabolism and risk of cardio-metabolic disease in non-diabetic and non-hypertensive breast cancer patients. 相似文献14.
Valentina Chiavaroli Maria Loredana Marcovecchio Tommaso de Giorgis Laura Diesse Francesco Chiarelli Angelika Mohn 《PloS one》2014,9(8)
Background
Subjects born small (SGA) and large (LGA) for gestational age have an increased risk of cardio-metabolic alterations already during prepuberty. Nevertheless, the progression of their cardio-metabolic profile from childhood to adolescence has not been fully explored. Our aim was to assess potential changes in the cardio-metabolic profile from childhood to adolescence in subjects born SGA and LGA compared to those born appropriate (AGA) for gestational age.Methods
This longitudinal study included 35 AGA, 24 SGA and 31 LGA subjects evaluated during childhood (mean age (±SD) 8.4±1.4 yr) and then re-assessed during adolescence (mean age 13.3±1.8 yr). BMI, blood pressure, insulin resistance (fasting insulin, HOMA-IR) and lipids were assessed. A cardio-metabolic risk z-score was applied and this consisted in calculating the sum of sex-specific z-scores for BMI, blood pressure, HOMA-IR, triglycerides and triglycerides:high-density lipoprotein cholesterol ratio.Results
Fasting insulin and HOMA-IR were higher in SGA and LGA than AGA subjects both during childhood (all P<0.01) and adolescence (all P<0.01). Similarly, the clustered cardio-metabolic risk score was higher in SGA and LGA than AGA children (both P<0.05), and these differences among groups increased during adolescence (both P<0.05). Of note, a progression of the clustered cardio-metabolic risk score was observed from childhood to adolescence within SGA and within LGA subjects (both P<0.05).Conclusions
SGA and LGA subjects showed an adverse cardio-metabolic profile during childhood when compared to AGA peers, with a worsening of this profile during adolescence. These findings indicate an overtime progression of insulin resistance and overall estimated cardiovascular risk from childhood to adolescence in SGA and LGA populations. 相似文献15.
Thimo Wiewelhove Christian Raeder Tim Meyer Michael Kellmann Mark Pfeiffer Alexander Ferrauti 《PloS one》2015,10(10)
Aim
Our study aimed to investigate changes of different markers for routine assessment of fatigue and recovery in response to high-intensity interval training (HIIT).Methods
22 well-trained male and female team sport athletes (age, 23.0 ± 2.7 years; V̇O2max, 57.6 ± 8.6 mL·min·kg−1) participated in a six-day running-based HIIT-microcycle with a total of eleven HIIT sessions. Repeated sprint ability (RSA; criterion measure of fatigue and recovery), countermovement jump (CMJ) height, jump efficiency in a multiple rebound jump test (MRJ), 20-m sprint performance, muscle contractile properties, serum concentrations of creatinkinase (CK), c-reactive protein (CRP) and urea as well as perceived muscle soreness (DOMS) were measured pre and post the training program as well as after 72 h of recovery.Results
Following the microcycle significant changes (p < 0.05) in RSA as well as in CMJ and MRJ performance could be observed, showing a decline (%Δ ± 90% confidence limits, ES = effect size; RSA: -3.8 ± 1.0, ES = -1.51; CMJ: 8.4 ± 2.9, ES = -1.35; MRJ: 17.4 ± 4.5, ES = -1.60) and a return to baseline level (RSA: 2.8 ± 2.6, ES = 0.53; CMJ: 4.1 ± 2.9, ES = 0.68; MRJ: 6.5 ± 4.5, ES = 0.63) after 72 h of recovery. Athletes also demonstrated significant changes (p < 0.05) in muscle contractile properties, CK, and DOMS following the training program and after the recovery period. In contrast, CRP and urea remained unchanged throughout the study. Further analysis revealed that the accuracy of markers for assessment of fatigue and recovery in comparison to RSA derived from a contingency table was insufficient. Multiple regression analysis also showed no correlations between changes in RSA and any of the markers.Conclusions
Mean changes in measures of neuromuscular function, CK and DOMS are related to HIIT induced fatigue and subsequent recovery. However, low accuracy of a single or combined use of these markers requires the verification of their applicability on an individual basis. 相似文献16.
Purpose
Left ventricular (LV) enlargement has been linked to sudden cardiac death among young athletes. This study aimed to model the effect of long-term incessant endurance training on LV dimensions in female adolescent runners.Methods
Japanese female adolescent competitive distance runners (n = 36, age: 15 years, height: 158.1 ± 4.6 cm, weight: 44.7 ± 6.1 kg, percent body fat: 17.0 ± 5.2%) underwent echocardiography and underwater weighing every 6 months for 3 years. Since the measurement occasions varied across subjects, multilevel analysis was used for curvilinear modeling of changes in running performance (velocities in 1500 m and 3000 m track race), maximal oxygen uptake (VO2max), body composition, and LV dimensions.Results
Initially, LV end-diastolic dimension (LVEDd) and LV mass were 47.0 ± 3.0 mm and 122.6 ± 15.7 g, respectively. Running performance and VO2max improved along with the training duration. The trends of changes in fat-free mass (FFM) and LVEDd were similarly best described by quadratic polynomials. LVEDd did not change over time in the model including FFM as a covariate. Increases in LV wall thicknesses were minimal and independent of FFM. LV mass increased according to a quadratic polynomial trend even after adjusting for FFM.Conclusions
FFM was an important factor determining changes in LVEDd and LV mass. Although running performance and VO2max were improved by continued endurance training, further LV cavity enlargement hardly occurred beyond FFM gain in these adolescent female runners, who already demonstrated a large LVEDd. 相似文献17.
Scott E. Crouter Sarah D. de Ferranti Jessica Whiteley Sarah K. Steltz Stavroula K. Osganian Henry A. Feldman Laura L. Hayman 《PloS one》2015,10(10)
Background
Less than 45% of U.S. children meet the 60 min.d-1 physical activity (PA) guideline. Structured after-school PA programing is one approach to help increase activity levels. This study aimed to evaluate the feasibility and short-term impact of a supervised after-school PA and nutrition education program on activity levels.Methods
Forty-two 3rd-5th graders from an inner-city school in Boston, MA were randomly assigned to a 10-wk after-school program of either: 1) weekly nutrition education, or 2) weekly nutrition education plus supervised PA 3 d.wk-1 at a community-based center. At baseline and follow-up, PA was measured using accelerometry and fitness (VO2max) was estimated using the PACER 15-m shuttle run. Additional measures obtained were non-fasting finger stick total cholesterol (TC) and glucose levels, waist circumference (WC), body mass index (BMI), percent body fat (%BF), and blood pressure (BP). Values are presented as mean±SE, unless noted otherwise.Results
Thirty-six participants completed the study (mean±SD; age 9.7±0.9 years). Participants attended >80% of the sessions. After adjusting for accelerometer wear time and other design factors, light and moderate-to-vigorous PA (MVPA) increased in the nutrition+PA group (+21.5±14.5 and +8.6±8.0 min.d-1, respectively) and decreased in the nutrition only group (-35.2±16.3 and -16.0±9.0 min.d-1, respectively); mean difference between groups of 56.8±21.7 min.d-1 (light PA, p = 0.01) and 24.5±12.0 min.d-1 (MVPA, p = 0.04). Time spent in sedentary behaviors declined in the nutrition+PA group (-14.8±20.7 min.d-1) and increased in the nutrition only group (+55.4±23.2 min.d-1); mean difference between groups of -70.2±30.9 min.d-1 (p = 0.02). Neither group showed changes in TC, BP, WC, %BF, BMI percentile, or fitness (p>0.05).Conclusions
The supervised afterschool community-based nutrition and PA program was well accepted and had high attendance. The changes in light PA and MVPA has potential to promote weight maintenance in inner-city elementary school children, however longer term studies with larger samples are needed.Trial Registration
ClinicalTrials.gov NCT01104038 相似文献18.
Lucyna Mastalerz Magdalena Celińska-L?wenhoff Piotr Krawiec Bogdan Batko Witold T?ustochowicz Anetta Undas 《PloS one》2015,10(11)
Objectives
Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome), we investigated whether fibrin clot properties are unfavorably altered in EGPA.Methods
Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male), aged 48 (range, 21–80) years. The control group comprised 34 age- and sex- matched volunteers.Results
Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10−9 cm2), faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s), thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07), higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L), and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min); all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%.Conclusion
This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease. 相似文献19.
Quan-ming Zhao Xin Zhao Ting-ting Feng Ming-duo Zhang Xu-cui Zhuang Xue-cheng Zhao Li-qin Li De-peng Li Yu Liu 《PloS one》2013,8(4)
Background
Detection of vulnerable plaques could be clinically significant in the prevention of cardiovascular events. We aimed to compare Fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in vulnerable and stable plaques, and investigate the feasibility of predicting thrombosis events using Positron Emission Tomography/Computed Tomography (PET/CT) angiography.Methods
Atherosclerosis was induced in 23 male New Zealand white rabbits. The rabbits underwent pharmacological triggering to induce thrombosis. A pre-triggered PET/CTA scan and a post-triggered PET/CTA scan were respectively performed. 18F-FDG uptake by the aorta was expressed as maximal standardized uptake value (SUVmax) and mean SUV (SUVmean). SUVs were measured on serial 7.5 mm arterial segments.Results
Thrombosis was identified in 15 of 23 rabbits. The pre-triggered SUVmean and SUVmax were 0.768±0.111 and 0.804±0.120, respectively, in the arterial segments with stable plaque, and 1.097±0.189 and 1.229±0.290, respectively, in the arterial segments with vulnerable plaque (P<0.001, respectively). The post-triggered SUVmean and SUVmax were 0.849±0.167 and 0.906±0.191, respectively in the arterial segments without thrombosis, and 1.152±0.258 and 1.294±0.313, respectively in the arterial segments with thrombosis (P<0.001, respectively). The values of SUVmean in the pre-triggered arterial segments were used to plot a receiver operating characteristic curve (ROC) for predicting thrombosis events. Area under the curve (AUC) was 0.898. Maximal sensitivity and specificity (75.4% and 88.5%, respectively) were obtained when SUVmean was 0.882.Conclusions
Vulnerable and stable plaques can be distinguished by quantitative analysis of 18F-FDG uptake in the arterial segments in this rabbit model. PET/CT may be used for predicting thrombosis events and risk-stratification in patients with atherosclerotic disease. 相似文献20.
Ida Beate ?. ?sthus Antonella Sgura Francesco Berardinelli Ingvild Vatten Alsnes Eivind Br?nstad Tommy Rehn Per Kristian St?bakk H?vard Hatle Ulrik Wisl?ff Javaid Nauman 《PloS one》2012,7(12)