高强度间歇训练对武警战士T淋巴细胞稳态的影响

 目的 探讨高强度间歇训练(high-intensity interval training,HIIT)对武警战士T淋巴细胞稳态(Th1/Th2和TH17/Treg)的影响。方法 选取23名武警男性战士分别进行急性(1次)和短期(4周、3次/周)HIIT,于1次HIIT运动前、运动后即刻、运动后60 min及4周HIIT前后取静脉血利用流式细胞术测定细胞因子IFN-γ(Th1亚群)、IL-4(Th2亚群)、IL-17A(Th17亚群)、TGF-β(Treg亚群),以及Treg细胞活化标志物CD39、LAP和GARP相对表达量(用阳性细胞率表示)。结果 1次HIIT后即刻,Th1细胞IFN-γ表达上调(P<0.05),60 min后,Treg细胞GARP、LAP和CD39表达量升高(P<0.05),IFN-γ恢复(P>0.05);IL-4在各时间点均无显著性变化(P>0.05)。4周HIIT后,Treg细胞LAP表达下调(P<0.05)。未检测到IL-17A和TGF-β表达量。结论 1次急性HIIT暂时性破坏Th1/Th2稳态并使Th1/Th2平衡向Th1漂移,运动后恢复期具有免疫抑制作用的Treg细胞被动员,其作用可能参与T细胞稳态的调节与重建。短期(4周)HIIT诱导Treg细胞免疫抑制能力减弱,但T细胞稳态平衡无显著性改变。     

In‐season adaptations to intense intermittent training and sprint interval training in sub‐elite football players

This study investigated the in‐season effect of intensified training comparing the efficacy of duration‐matched intense intermittent exercise training with sprint interval training in increasing intermittent running performance, sprint ability, and muscle content of proteins related to ion handling and metabolism in football players. After the first two weeks in the season, 22 sub‐elite football players completed either 10 weeks of intense intermittent training using the 10‐20‐30 training concept (10‐20‐30, n = 12) or sprint interval training (SIT, n = 10; work/rest ratio: 6‐s/54‐s) three times weekly, with a ~20% reduction in weekly training time. Before and after the intervention, players performed a Yo‐Yo intermittent recovery test level 1 (Yo‐Yo IR1) and a 30‐m sprint test. Furthermore, players had a muscle biopsy taken from the vastus lateralis. Yo‐Yo IR1 performance increased by 330 m (95%CI: 178‐482, P ≤ 0.01) in 10‐20‐30, whereas no change was observed in SIT. Sprint time did not change in 10‐20‐30 but decreased by 0.04 second (95%CI: 0.00‐0.09, P ≤ 0.05) in SIT. Muscle content of HADHA (24%, P ≤ 0.01), PDH‐E1α (40%, P ≤ 0.01), complex I‐V of the electron transport chain (ETC) (51%, P ≤ 0.01) and Na⁺, K⁺‐ATPase subunits α₂ (33%, P ≤ 0.05) and β₁ (27%, P ≤ 0.05) increased in 10‐20‐30, whereas content of DHPR (27%, P ≤ 0.01) and complex I‐V of the ETC (31%, P ≤ 0.05) increased in SIT. Intense intermittent training, combining short sprints and a high aerobic load, is superior to regular sprint interval training in increasing intense intermittent running performance during a Yo‐Yo IR1 test and muscle content of PDH‐E1α and HADHA in sub‐elite football players.     

高强度间歇运动加重溃疡性结肠炎小鼠炎性反应的影响

 目的 探讨8周高强度间歇运动(high-intensity interval training,HIIT)预适应对溃疡性结肠炎(ulcerative colitis, UC)小鼠临床症状和炎性反应的影响。方法 45只雄性C57BL/6小鼠随机分为安静对照组(RC)、安静造模组(RM)和运动造模组(EM),RC组安静饲养8周后自由饮用蒸馏水7 d,RM和EM组分别安静饲养或进行8周HIIT后自由饮用葡聚糖硫酸钠(DSS)溶液7 d行UC造模。每天记录小鼠疾病活动指数(disease activity index,DAI);取结肠组织测量长度,HE染色行组织病理学观察;结肠组织匀浆后测定炎性反应因子白细胞介素-1β(IL-1β)、IL-6和肿瘤坏死因子-α(TNF-α)mRNA表达量。结果 与RC组比较,RM组小鼠结肠长度缩短(P＜0.05),DAI、组织病理学评分及炎性反应因子(IL-1β、IL-6和TNF-α)表达量升高(P＜0.05);与RM组比较,EM组结肠长度缩短(P＜0.05),DAI、组织病理学评分及IL-1β和TNF-α mRNA含量进一步上调(P＜0.05)。结论 长期HIIT预适应加重UC小鼠临床症状和炎性反应,因此HIIT的健康效应尚需进一步证实。     

Cognition in breast cancer survivors: A pilot study of interval and continuous exercise

Objectives

The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.

Mechanistic and methodological perspectives on the impact of intense interval training on post-exercise metabolism

The post-exercise recovery period is associated with an elevated metabolism known as excess post-exercise oxygen consumption (EPOC). The relationship between exercise duration and EPOC magnitude is thought to be linear whereas the relationship between EPOC magnitude and exercise intensity is thought to be exponential. Accordingly, near-maximal and supramaximal protocols such as high-intensity interval training (HIIT) and sprint interval training (SIT) protocols have been hypothesized to produce greater EPOC magnitudes than submaximal moderate-intensity continuous training (MICT). This review updates previous reviews by focusing on the impact of HIIT and SIT on EPOC. Research to date suggests small differences in EPOC post-HIIT compared to MICT in the immediate (<1 hour) recovery period, but greater EPOC values post-HIIT when examined over 24 hours. Conversely, differences in EPOC post-SIT are more pronounced, as SIT tends to produce a larger EPOC vs MICT at all time points. We discuss potential mechanisms that may drive the EPOC response to interval training (eg, glycogen resynthesis, mitochondrial uncoupling, and protein turnover among others) and also consider the role of EPOC as one of the potential contributors to fat loss following HIIT/SIT interventions. Lastly, we highlight a number of methodological shortcomings related to the measurement of EPOC following HIIT and SIT.     

两种恢复方式对士兵冲刺间歇训练效果的影响

 目的 探讨冲刺间歇训练时两种恢复方式(积极性恢复 vs. 消极性恢复)对士兵运动能力和训练效果的影响。方法 选取18名男性武警士兵完成6组冲刺间歇训练(30 s Wingate全力蹬车试验),间歇期(4 min)分别进行消极性恢复(即在功率自行车上休息)和积极性恢复(以1.1 W/kg负荷继续蹬车),每次Wingate试验时(不包括间歇期)记录峰值功率(PP)、平均功率(MP)、疲劳指数(FI)、总做功(TW)和心率(HR)等参数。结果 与消极性恢复比较,积极性恢复PP在第2次Wingate试验时降低(P<0.05),MP和HR在第4~6次Wingate试验时升高,差异均有统计学意义(P<0.05),FI和TW差异无统计学意义(P>0.05)。结论 积极性恢复可提高冲刺间歇训练后期的训练效果, 士兵应根据训练方案选择合理的恢复方式。     

The effect of high Intensity interval training versus moderate intensity continuous training on arterial stiffness and 24 h blood pressure responses: A systematic review and meta-analysis

Objectives

Greater arterial stiffness and poor 24 h blood pressure (BP) are recognized as indicators of poor cardiovascular health. Evidence has shown that high intensity interval training (HIIT) may be a superior alternative to moderate intensity continuous training (MICT) for improving cardiovascular disease risk factors such as cardiorespiratory fitness and vascular function. However, there are limited data comparing the effect of HIIT to MICT on central arterial stiffness and/or 24 h BP response. The purpose of this study was to compare HIIT versus MICT on central arterial stiffness and 24 h BP outcomes by systematic review and meta-analysis.

Effects of high‐intensity interval cycling performed after resistance training on muscle strength and hypertrophy

Aim of the study was to investigate whether high‐intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty‐two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high‐intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross‐sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P < 0.05) and REC (type I: 10.0 ± 2.7%, type IIA: 14.8 ± 4.3% type IIX: 20.8 ± 6.0%, P < 0.05). In contrast, RFD decreased and fascicle angle increased (P < 0.05) only after REC. Capillary density and estimated aerobic capacity increased (P < 0.05) only after REC. These results suggest that high‐intensity interval cycling performed after heavy‐resistance exercise may not inhibit resistance exercise‐induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high‐intensity cycling after heavy‐resistance exercise may decrease RFD partly due to muscle architectural changes.     

Changes in inflammation markers after a 10-week high-intensity combined strength and endurance training block in women: The effect of hormonal contraceptive use

ObjectivesThe influence of hormonal contraceptives (HC) on inflammation and body composition after high-intensity combined strength and endurance training was investigated.DesignActive healthy women formed two training groups: HC users (HCU, n = 9) and those who had never used HC (NHC, n = 9). Training included two strength training sessions and two high-intensity interval training sessions per week for 10 weeks.MethodsBefore (PRE) and after (POST) the training intervention, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) concentrations were measured. Dual-energy X-ray absorptiometry was used to estimate fat mass (FM), abdominal fat mass (aFM), and lean mass (LM).ResultsCirculating concentrations of hs-CRP decreased significantly in the NHC from pre to post with −0.46 mg l⁻¹ (95% CI: −0.78, −0.14, p = 0.009, ES = 0.434), whereas a significant increase was observed in HCU from pre to post with 0.89 mg l⁻¹ (95% CI: 1.66, 0.12, p = 0.048, ES = 1.988) with a significant between-group difference (p = 0.015). In addition, hs-CRP concentration was significantly higher in HCU than in NHC after training (p = 0.036) at post. Lean mass increased significantly more in NHC than in HCU (p = 0.049).ConclusionsHigh-intensity combined strength and endurance training can modify inflammation and body composition of women. The present study showed that inflammation, in terms of hs-CRP was higher post training in HCU than NHC, which may be associated with smaller gains in lean mass in response to training.     

Effect of beta2‐adrenergic agonist and resistance training on maximal oxygen uptake and muscle oxidative enzymes in men

While beta₂‐adrenoceptor stimulation has been shown to increase lean mass and to alter metabolic properties of skeletal muscle, adaptations in muscle oxidative enzymes and maximal oxygen uptake (O_2max) in response to beta₂‐adrenergic agonist treatment are inadequately explored in humans, particularly in association with resistance training. Herein, we investigated beta₂‐adrenergic‐induced changes in O_2max, leg and arm composition, and muscle content of oxidative enzymes in response to treatment with the selective beta₂‐adrenergic agonist terbutaline with and without concurrent resistance training in young men. Forty‐six subjects were randomized to 4 weeks of lifestyle maintenance (n = 23) or resistance training (n = 23). Within the lifestyle maintenance and resistance training group, subjects received daily terbutaline (8 × 0.5 mg) (n = 13) or placebo (n = 10) treatment. No apparent treatment by training interactions was observed during the study period. Terbutaline increased leg and arm lean mass with the intervention, whereas no treatment differences were observed in absolute O_2max and incremental peak power output (iPPO). Treatment main effects were observed for O₂‐reserve (P < .05), O_2max relative to body mass (P < .05), O_2max relative to leg lean mass (P < .01), and iPPO relative to leg lean mass, in which terbutaline had a negative effect compared with placebo. Furthermore, content of electron transport chain complex I‐V decreased by 11% (P < .05) for terbutaline compared with placebo. Accordingly, chronic treatment with the selective beta₂‐adrenergic agonist terbutaline may negatively affect O_2max and iPPO in relative terms, but not in absolute.     

Effects of 6‐month aerobic interval training on skeletal muscle metabolism in middle‐aged metabolic syndrome patients

Aerobic interval training (AIT ) improves the health of metabolic syndrome patients (MetS) more than moderate intensity continuous training. However, AIT has not been shown to reverse all metabolic syndrome risk factors, possibly due to the limited duration of the training programs. Thus, we assessed the effects of 6 months of AIT on cardio‐metabolic health and muscle metabolism in middle‐aged MetS. Eleven MetS (54.5±0.7 years old) underwent 6 months of 3 days a week supervised AIT program on a cycle ergometer. Cardio‐metabolic health was assessed, and muscle biopsies were collected from the vastus lateralis prior and at the end of the program. Body fat mass (−3.8%), waist circumference (−1.8%), systolic (−10.1%), and diastolic (−9.3%) blood pressure were reduced, whereas maximal fat oxidation rate and VO _2peak were significantly increased (38.9% and 8.0%, respectively; all P <.05). The remaining components of cardio‐metabolic health measured (body weight, blood cholesterol, triglycerides, and glucose) were not changed after the intervention, and likewise, insulin sensitivity (CSi) remained unchanged. Total AMPK (23.4%), GLUT 4 (20.5%), endothelial lipase (33.3%) protein expression, and citrate synthase activity (26.0%) increased with training (P <.05). Six months of AIT in MetS raises capacity for fat oxidation during exercise and increases VO _2peak in combination with skeletal muscle improvements in mitochondrial enzyme activity. Muscle proteins involved in glucose, fat metabolism, and energy cell balance improved, although this was not reflected by parallel improvements in insulin sensitivity or blood lipid profile.