高强度间歇运动可改善大鼠的心肺耐力

背景:最大摄氧量(VO2max)是评定心肺耐力及运动能力最直接有效的客观指标,但目前研究中反映大鼠较长时间最大摄氧量变化数据的文章较少,尚未见有关高强度间歇训练对大鼠增龄过程中心肺耐力持续变化影响的相关报道。目的:探讨16周高强度间歇训练对大鼠心肺耐力的改善作用,并通过对29周龄大鼠最大摄氧量持续16周测定,为实验动物训练强度的量化提供数据参考。方法:将28只29周龄雄性Wistar大鼠分为2组:安静对照组大鼠正常饮食生活,无训练;高强度间歇训练组大鼠进行高强度(90%最大摄氧量)、低强度(50%最大摄氧量)的间歇运动,为期16周,每周5次,平均每2周测定最大摄氧量、完成最大摄氧量测试对应的最大跑速变化,并针对2组大鼠最大摄氧量和最大跑速值进行对比及相关分析。实验经北京体育大学运动科学实验伦理委员会批准(2015025)。结果与结论:①29-45周龄增龄过程中最大摄氧量出现下降-上升-下降波动,16周后,高强度间歇训练组大鼠最大摄氧量下降了31.6%,安静对照组大鼠最大摄氧量下降了47.9%,高强度间歇训练组大鼠最大摄氧量显著高于安静对照组(P<0.01);②干预6,8,16周时高强度间歇训练组最大摄氧量下降幅度显著低于安静对照组(P<0.05或P<0.01);③干预4,8周时高强度间歇训练组最大跑速值显著高于安静对照组(P<0.05或P<0.01);④最大摄氧量与最大跑速的相对值呈正相关;⑤结果说明,年龄的增加是大鼠心肺耐力下降的不可逆因素,但高强度间歇训练可延缓心肺耐力下降趋势;高强度间歇训练干预6周后可明显降低大鼠因增龄导致的心肺耐力下降幅度,8周后可有效延缓大鼠因增龄导致的心肺耐力下降;高强度间歇训练干预4周后大鼠最大跑速提高,运动能力增强。     

Short-term exercise training improves diaphragm antioxidant capacity and endurance

These experiments tested the hypothesis that short-term endurance exercise training would rapidly improve (within 5 days) the diaphragm oxidative/antioxidant capacity and protect the diaphragm against contraction-induced oxidative stress. To test this postulate, male Sprague-Dawley rats (6 weeks old) ran on a motorized treadmill for 5 consecutive days (40–60 min · day⁻¹) at approximately 65% maximal oxygen uptake. Costal diaphragm strips were excised from both sedentary control (CON, n=14) and trained (TR, n=13) animals 24 h after the last exercise session, for measurement of in vitro contraction properties and selected biochemical parameters of oxidative/antioxidant capacity. Training did not alter diaphragm force-frequency characteristics over a full range of submaximal and maximal stimulation frequencies (P > 0.05). In contrast, training improved diaphragm resistance to fatigue as contraction forces were better-maintained by the diaphragms of the TR animals during a submaximal 60-min fatigue protocol (P < 0.05). Following the fatigue protocol, diaphragm strips from the TR animals contained 30% lower concentrations of lipid hydroperoxides compared to CON (P < 0.05). Biochemical analysis revealed that exercise training increased diaphragm oxidative and antioxidant capacity (citrate synthase activity +18%, catalase activity +24%, total superoxide dismutase activity +20%, glutathione concentration +10%) (P < 0.05). These data indicate that short-term exercise training can rapidly elevate oxidative capacity as well as enzymatic and non-enzymatic antioxidant defenses in the diaphragm. Furthermore, this up-regulation in antioxidant defenses would be accompanied by a reduction in contraction-induced lipid peroxidation and an increased fatigue resistance. Accepted: 6 August 1999     

Respiratory muscle training improves swimming endurance in divers

Respiratory muscles can fatigue during prolonged and maximal exercise, thus reducing performance. The respiratory system is challenged during underwater exercise due to increased hydrostatic pressure and breathing resistance. The purpose of this study was to determine if two different respiratory muscle training protocols enhance respiratory function and swimming performance in divers. Thirty male subjects (23.4 ± 4.3 years) participated. They were randomized to a placebo (PRMT), endurance (ERMT), or resistance respiratory muscle training (RRMT) protocol. Training sessions were 30 min/day, 5 days/week, for 4 weeks. PRMT consisted of 10-s breath-holds once/minute, ERMT consisted of isocapnic hyperpnea, and RRMT consisted of a vital capacity maneuver against 50 cm H₂O resistance every 30 s. The PRMT group had no significant changes in any measured variable. Underwater and surface endurance swim time to exhaustion significantly increased after RRMT (66%, P < 0.001; 33%, P = 0.003) and ERMT (26%, P = 0.038; 38%, P < 0.001). Breathing frequency (f _b) during the underwater endurance swim decreased in RRMT (23%, P = 0.034) and tidal volume (V _T) increased in both the RRMT (12%, P = 0.004) and ERMT (7%, P = 0.027) groups. Respiratory endurance increased in ERMT (216.7%) and RRMT (30.7%). Maximal inspiratory and expiratory pressures increased following RRMT (12%, P = 0.015, and 15%, P = 0.011, respectively). Results from this study indicate that respiratory muscle fatigue is a limiting factor for underwater swimming performance, and that targeted respiratory muscle training (RRMT > ERMT) improves respiratory muscle and underwater swimming performance.     

Strength training improves cycling efficiency in master endurance athletes

The purpose of this study was to test the effect of a 3-week strength training program of knee extensor muscles on cycling delta efficiency in master endurance athletes. Nine master (age 51.5 ± 5.5 years) and 8 young (age 25.6 ± 5.9 years) endurance athletes with similar training levels participated in this study. During three consecutive weeks, all the subjects were engaged in a strength training program of the knee extensor muscles. Every week, they performed three training sessions consist of 10 × 10 knee extensions at 70% of maximal repetition with 3 min rest between in a leg extension apparatus. Maximal voluntary contraction torque (MVC torque) and force endurance (End) were assessed before, after every completed week of training, and after the program. Delta efficiency (DE) in cycling was evaluated before and after the training period. Before the training period, MVC torque, End, and DE in cycling were significantly lower in masters than in young. The strength training induced a significant improvement in MVC torque in all the subjects, more pronounced in masters (+17.8% in masters vs. +5.9% in young, P < 0.05). DE in cycling also significantly increased after training in masters, whereas it was only a trend in young. A significant correlation (r = 0.79, P < 0.01) was observed between MVC torque and DE in cycling in masters. The addition of a strength training program for the knee extensor muscles to endurance-only training induced a significant improvement in strength and cycling efficiency in master athletes. This enhancement in muscle performance alleviated all the age-related differences in strength and efficiency.     

Respiratory muscle endurance training in humans increases cycling endurance without affecting blood gas concentrations

Isolated respiratory muscle endurance training (RMT) can prolong constant-intensity cycling performance. We tested whether RMT affects O₂ supply during exercise, i.e. whether the partial pressure of oxygen in arterial blood (P _aO₂) and/or its oxygen saturation (S _aO₂) are higher during exercise after RMT than before. A group of 28 sedentary subjects were randomly assigned to either an RMT (n=13) or a control group (n=15). The RMT consisted of 40×30 min sessions of normocapnic hyperpnoea. The control group did not perform any training. Breathing and cycling endurance time as well as P _aO₂ and S _aO₂ during cycling at a constant intensity of 70% maximum power output were measured before and after the RMT or the control period. Mean breathing endurance increased significantly after RMT compared to control [RMT 5.2 (SD 2.9) vs 38.1 (SD 6.8) min, control 6.5 (SD 5.7) vs 6.4 (SD 7.6) min; P<0.01], as did mean cycling endurance [RMT 35.6 (SD 11.9) vs 44.0 (SD 17.2) min, control 32.8 (SD 11.6) vs 31.4 (SD 14.4) min; P<0.05]. The RMT did not affect P _aO₂ which ranged from 11.6 to 12.3 kPa (87–92 mmHg), and S _aO₂ which ranged from 96% to 98% throughout all tests. In conclusion, RMT substantially increased breathing and cycling endurance in sedentary subjects. These changes, however, cannot be attributed to increased O₂ supply, as neither P _aO₂ nor S _aO₂ were increased during exercise after RMT. Electronic Publication     

High-intensity intermittent running training improves pulmonary function and alters exercise breathing pattern in children

We investigated the effects of short duration running training on resting and exercise lung function in healthy prepubescent children. One trained group (TrG) (n = 9; three girls and six boys; age = 9.7 ± 0.9 year) participated in 8 weeks of high-intensity intermittent running training and was compared to a control group (ContG) (n = 9; four girls and five boys; age = 10.3 ± 0.7 year). Before and after the 8-week period, the children performed pulmonary function tests and an incremental exercise test on a cycle ergometer. After the 8-week period, no change was found in pulmonary function in ContG. Conversely, an increase in forced vital capacity (FVC) (+7 ± 4% ; P = 0.026), forced expiratory volume in one second (+11 ± 6% ; P = 0.025), peak expiratory flows (+17 ± 4% ; P = 0.005), maximal expiratory flows at 50% (+16 ± 10% ; P = 0.019) and 75% (+15 ± 8% ; P = 0.006) of FVC were reported in TrG. At peak exercise, TrG displayed higher values of peak oxygen consumption (+15 ± 4% ; P<0.001), minute ventilation (+16 ± 5% ; P = 0.033) and tidal volume (+15 ± 5% ; P = 0.019) after training. At sub-maximal exercise, ventilatory response to exercise was lower (P = 0.017) in TrG after training, associated with reduced end-tidal partial oxygen pressure (P<0.05) and higher end-tidal partial carbon dioxide pressure (P = 0.026). Lower deadspace volume relative to tidal volume was found at each stage of exercise in TrG after training (P<0.05). Eight weeks of high-intensity intermittent running training enhanced resting pulmonary function and led to deeper exercise ventilation reflecting a better effectiveness in prepubescent children.     

Decreased exercise blood lactate concentrations after respiratory endurance training in humans

For many years, it was believed that ventilation does not limit performance in healthy humans. Recently, however, it has been shown that inspiratory muscles can become fatigued during intense endurance exercise and decrease their exercise performance. Therefore, it is not surprising that respiratory endurance training can prolong intense constant-intensity cycling exercise. To investigate the effects of respiratory endurance training on blood lactate concentration and oxygen consumption (V˙O₂) during exercise and their relationship to performance, 20?healthy, active subjects underwent 30?min of voluntary, isocapnic hyperpnoea 5 days a week, for 4 weeks. Respiratory endurance tests, as well as incremental and constant-intensity exercise tests on a cycle ergometer, were performed before and after the 4-week period. Respiratory endurance increased from 4.6 (SD 2.5) to 29.1?(SD 4.0)?min (P?P?V˙O₂ did not change at any exercise intensity whereas blood lactate concentration was lower at the end of the incremental [10.4 (SD 2.1) vs 8.8?(SD 1.9)?mmol?·?l^?1, P??1, P?相似文献   

大强度耐力运动抑制骨骼肌线粒体的生物合成

背景：耐力运动对骨骼肌线粒体生成影响的研究多采用中小强度,长期大强度对其有何影响还不清楚,这种影响是否涉及5’-一磷酸腺苷激活的蛋白激酶(AMPK)、沉默信息调节因子2相关酶1(SIRT1)等调节线粒体生成的信号分子也未见报道。 目的：观察AMPK/SIRT1信号级联在7周不同强度耐力运动中对骨骼肌线粒体生物合成的影响。 方法：42只雄性SD大鼠分为安静组、中等强度运动组和大强度运动组。运动负荷为中等强度组28 m/min,60 min/d、大强度组38 m/min,60 min/d,每周运动5 d,休息2 d,共7周。运动组动物分别在运动后即刻、6 h和24 h取材。荧光定量PCR检测骨骼肌PGC-1α 、SIRT1基因表达,Western blot测定P-AMPK、SIRT1蛋白表达。 结果与结论：①中等强度运动后即刻、6 h、24 h,骨骼肌PGC-1α mRNA表达分别为安静组的362%(P < 0.01)、657%(P < 0.01)、116%,P-AMPK蛋白表达分别为安静组的112%、163%(P < 0.05)、129%(P < 0.05),SIRT1蛋白和mRNA表达分别为安静组的55%(P < 0.05)、86%、103%和109%、155%(P < 0.05)、132%(P < 0.05)。②大强度运动后即刻、6 h、24 h,骨骼肌PGC-1α mRNA表达分别为安静组的274%(P < 0.01)、130%(P < 0.05)、68%(P < 0.05),P-AMPK蛋白表达分别为安静组的235%(P < 0.01)、166%(P < 0.05)、160%(P < 0.05),SIRT1蛋白和mRNA表达分别为安静组的199%(P < 0.01)、166%(P < 0.05)、164%(P < 0.05)和255%(P < 0.01)、292%(P < 0.01)、122%。结果表明：①7周中等强度耐力运动显著增加骨骼肌PGC-1α基因表达,其机制可能涉及AMPK/SIRT1信号级联。②7周大强度耐力运动造成骨骼肌PGC-1α基因表达在运动后24 h时被抑制,这一过程是以非AMPK/SIRT1信号级联依赖性方式进行的。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans

The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (V˙O_{2 max}) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle. Accepted: 10 November 1998     

Combined lower body endurance and upper body resistance training improves performance and health parameters in healthy active elderly

We investigated the effects of combined lower body (LB) endurance and upper body (UB) resistance training on endurance, strength, blood lipid profile and body composition in active older men. Ten healthy still active men (73 ± 4 years, peak: 36 (31–41) ml min⁻¹ kg⁻¹) were tested before and after 14 weeks of combined training (3 times week⁻¹). Training consisted of 3 × 12 min of high intensity interval training on a bicycle for endurance interspersed by 3 × 12 min of UB resistance exercises. peak during leg cycling and arm cranking, isokinetic torque of knee extensor and shoulder abductor and the cross-sectional area (CSA) of several muscles from UB and LB were measured. Sagittal abdominal diameter (SAD) and abdominal fat area were measured on MRI scans. Total body composition was assessed by hydrostatic weighing (HW) and dual-energy X-ray absorptiometry (DEXA). Blood lipid profile was assessed before and after training. By the end of the training period, peak (l min⁻¹) increased significantly by 9 and 16% in leg cycling and arm cranking tests, respectively. Maximal isokinetic torque increased both for the knee extensor and shoulder abductor muscle groups. CSA increased significantly in deltoid muscle. Percentage of body fat decreased by 1.3% (P < 0.05) and abdominal fat and SAD decreased by 12 and 6%, respectively (P < 0.01). There was also a significant decrease in total cholesterol and low-density lipoprotein. Thus, combined LB endurance and UB resistance training can improve endurance, strength, body composition and blood lipid profile even in healthy active elderly.     

Association of adiponectin polymorphism with cord blood adiponectin concentrations and intrauterine growth

To assess whether adiponectin gene (ADIPOQ) polymorphism is associated with intrauterine fetal growth and cord blood adiponectin, we investigated eight single-nucleotide polymorphisms (SNPs; rs182052, rs710445, rs16861205, rs12495941, rs1501299, rs3774261, rs2082940 and rs266729) in ADIPOQ and birth weight and cord blood adiponectin in 526 healthy neonates. We found that the neonates carrying the G allele of rs266729 had a significantly greater birth weight s.d. score than those homozygous for the C allele (CC: -0.06±0.75 versus CG: 0.20±0.64 versus GG: 0.07±0.78; P=1.65 × 10(-3), adjusted P=9.90 × 10(-3)). However, this difference was not significant after adjustment for cord blood adiponectin (P=0.04, adjusted P=0.26). The rs266729 SNP was strongly associated with cord blood adiponectin; neonates with rs266729 GG had the highest adiponectin (CC: 34.1±20.2 versus CG: 44.3±26.1 versus GG: 54.1±36.7?μg?ml(-1), P=2.80 × 10(-9), adjusted P=1.68 × 10(-8)). This association remained after adjustment for birth weight s.d. score (P=6.63 × 10(-8), adjusted P=3.98 × 10(-7)). Our results suggest that the influence of the rs266729 SNP in ADIPOQ on birth weight may be dependent on circulating adiponectin.     

Erythropoietic adaptations to endurance training

Summary Erythropoietic adaptations involving the oxygen dissociation curve (ODC) and erythropoietin production have been implicated in the etiology of reduced blood haemoglobin concentrations in sportspersons (known as sports anaemia). A significant increase in the half-saturation pressure indicating a right-shift in the ODC was measured in 34 male [25.8–27.4 mmHg (3.44–3.65 kPa)] and 16 female (25.8–27.7 mmHg (3.44–3.69 kPa)] trained distance runners (P<0.01 for both genders) after completing a standard 42-km marathon. Erythrocyte 2,3-diphosphoglycerate concentrations measured concurrently were unaltered by exercise, although consistently higher in the female compared to the male athletes (P<0.05). The serum erythropoietin (EPO) concentrations of 15 male triathletes (26.3 U · ml^–1) were significantly lower than those of 45 male distance runners (31.6 U · ml^–1 ;P<0.05). However, the mean serum EPO concentrations of male and female athletes engaged in a variety of sports were not different from those of sedentary control subjects of both sexes (26.5–35.3 U · ml^–1). Furthermore, the serum EPO concentrations were unaltered after prolonged strenuous exercise in 20 male marathon runners. These data suggest that the haematological status of these endurance athletes is in fact normal and that the observed shift in the ODC, while providing a physiological advantage during exercise, has no measurable effect on the erythropoietic drive.     

Neuromuscular adaptations during concurrent strength and endurance training versus strength training

The purpose of this study was to investigate effects of concurrent strength and endurance training (SE) (2 plus 2 days a week) versus strength training only (S) (2 days a week) in men [SE: n=11; 38 (5) years, S: n=16; 37 (5) years] over a training period of 21 weeks. The resistance training program addressed both maximal and explosive strength components. EMG, maximal isometric force, 1 RM strength, and rate of force development (RFD) of the leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF) throughout the lengths of 4/15–12/15 (L _f) of the femur, muscle fibre proportion and areas of types I, IIa, and IIb of the vastus lateralis (VL), and maximal oxygen uptake (V˙O_2max) were evaluated. No changes occurred in strength during the 1-week control period, while after the 21-week training period increases of 21% (p<0.001) and 22% (p<0.001), and of 22% (p<0.001) and 21% (p<0.001) took place in the 1RM load and maximal isometric force in S and SE, respectively. Increases of 26% (p<0.05) and 29% (p<0.001) occurred in the maximum iEMG of the VL in S and SE, respectively. The CSA of the QF increased throughout the length of the QF (from 4/15 to 12/15 L _f) both in S (p<0.05–0.001) and SE (p<0.01–0.001). The mean fibre areas of types I, IIa and IIb increased after the training both in S (p<0.05 and 0.01) and SE (p<0.05 and p<0.01). S showed an increase in RFD (p<0.01), while no change occurred in SE. The average iEMG of the VL during the first 500 ms of the rapid isometric action increased (p<0.05–0.001) only in S. V˙O_2max increased by 18.5% (p<0.001) in SE. The present data do not support the concept of the universal nature of the interference effect in strength development and muscle hypertrophy when strength training is performed concurrently with endurance training, and the training volume is diluted by a longer period of time with a low frequency of training. However, the present results suggest that even the low-frequency concurrent strength and endurance training leads to interference in explosive strength development mediated in part by the limitations of rapid voluntary neural activation of the trained muscles. Electronic Publication     

Critical determinants of endurance performance in middle-aged and elderly endurance runners with heterogeneous training habits

Summary The current investigation was designed to determine which factor or what combination of factors would best account for distance running performance in middle-aged and elderly runners (mean age 57.5 years SD±9.7) with heterogeneous training habits. Among 35 independent variables which were arbitrarily selected as possible prerequisites in the distance running performance of these runners, oxygen uptake at lactate threshold (LT) (r=0.781∼0.889), maximal oxygen uptake (r=0.751∼0.886), and chronological age (r=−0.736∼−0.886) were found to be the 3 predictor variables showing the highest correlations with the mean running velocity at 5 km (V _{5 km}), 10 km (V _{10 km}), and marathon (V _M). When all independent variables were used in a multiple regression analysis, any 3 or 4 variables selected from among at LT, chronological age, systolic blood pressure (SBP), atherogenic index (AI), and Katsura index (KI) were found to give the best explanation ofV _{5 km},V _{10 km}, orV _M in a combined linear model. Linear multiple regression equations constructed for predicting the running performances were:V _{5 km}=0.046X ₁−0.026X ₂−0.0056X ₃+5.17,V _{10 km}=0.028X ₁−0.028X ₂−0.190X ₄−1.34X ₅+6.45, andV _M=−0.0400X ₂−0.324X ₄−1.16X ₅+7.36, where at LT (ml·min⁻¹·kg⁻¹),X ₂ = chronological age,X ₃=SBP,X ₄=AI, andX ₅=KI. We suggest that distance running performance of middle-aged and elderly runners could be predicted with a relatively high accuracy by a single predictor of at LT or , or by a combination of either of these predictors with more easily measurable indices such as age, AI, KI, or SBP. The prediction equations which have been developed can be applied to a larger population of middle-aged and elderly runners. Data were collected at the Human Performance Laboratory, Hiroshima University     

Neuromuscular adaptations during combined strength and endurance training in endurance runners: maximal versus explosive strength training or a mix of both

This study compared the effects of mixed maximal strength and explosive strength training with maximal strength training and explosive strength training combined with endurance training over an 8-week training intervention. Male subjects (age 21–45 years) were divided into three strength training groups, maximal (MAX, n = 11), explosive (EXP, 10) and mixed maximal and explosive (MIX, 9), and a circuit training control group, (CON, 7). Strength training one to two times a week was performed concurrently with endurance training three to four times a week. Significant increases in maximal dynamic strength (1RM), countermovement jump (CMJ), maximal muscle activation during 1RM in MAX and during CMJ in EXP, peak running speed (S _peak) and running speed at respiratory compensation threshold (RCT_speed) were observed in MAX, EXP and MIX. Maximal isometric strength and muscle activation, rate of force development (RFD), maximal oxygen uptake $ \left( {\dot{V}{\text{O}}_{2\max } } \right) $ and running economy (RE) at 10 and 12 km hr^?1 did not change significantly. No significant changes were observed in CON in maximal isometric strength, RFD, CMJ or muscle activation, and a significant decrease in 1RM was observed in the final 4 weeks of training. RE in CON did not change significantly, but significant increases were observed in S _peak, RCT_speed and $ \left( {\dot{V}{\text{O}}_{2\max } } \right). $ Low volume MAX, EXP and MIX strength training combined with higher volume endurance training over an 8-week intervention produced significant gains in strength, power and endurance performance measures of S _peak and RCT_speed, but no significant changes were observed between groups.     

Body composition is related to increase in plasma adiponectin levels rather than training in young obese men

We assessed the major factors regulating adiponectin levels and the influence of exercise training on adiponectin levels in young obese men (19.2±1.1 yrs, BMI: 31.1±4.2, %fat: 27.2±3.9%). Subjects were separated into three groups (aerobic exercise group [AE: n=7], aerobic and resistance exercise group [AE+RE: n=7], control group [n=7]). AE underwent an 8-week training program (three times per week, more than 30 min endurance exercise at ventilatory threshold (VT) intensity). AE+RE went through resistance exercise two or three times per week together with the above endurance exercise for 5 months. Prior to intervention (n=21), adiponectin levels were significantly correlated with percentage of fat. Stepwise multiple regression analysis revealed that percent body fat was an independent predictor of basal adiponectin levels (r²=0.370; P<0.01). After intervention, fat mass, and VT were significantly improved in AE. AE+RE exhibited significant reduction in weight, BMI, percent body fat and fat mass, and had significantly increased VT, cycling power and torque. Insulin was not changed in both groups. The control group exhibited no significant change in any variables. Although adiponectin levels were unchanged in the three groups, a significant negative correlation between delta fat mass and delta adiponectin levels was observed (n=21, r=–0.461, P<0.05). In addition, delta percent body fat was an independent predictor of delta adiponectin levels (r²=0.327, P<0.05). These findings indicate that for increasing the adiponectin level, improvement of the body composition of young obese men is more important than the way training is performed.     

Suggestion for linkage of chromosome 1p35.2 and 3q28 to plasma adiponectin concentrations in the GOLDN Study

Background  

Adiponectin is inversely associated with obesity, insulin resistance, and atherosclerosis, but little is known about the genetic pathways that regulate the plasma level of this protein. To find novel genes that influence circulating levels of adiponectin, a genome-wide linkage scan was performed on plasma adiponectin concentrations before and after 3 weeks of treatment with fenofibrate (160 mg daily) in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study. We studied Caucasian individuals (n = 1121) from 190 families in Utah and Minnesota. Of these, 859 individuals from 175 families had both baseline and post-fenofibrate treatment measurements for adiponectin. Plasma adiponectin concentrations were measured with an ELISA assay. All participants were typed for microsatellite markers included in the Marshfield Mammalian Genotyping Service marker set 12, which includes 407 markers spaced at approximately 10 cM regions across the genome. Variance components analysis was used to estimate heritability and to perform genome-wide scans. Adiponectin was adjusted for age, sex, and field center. Additional models also included BMI adjustment.