Effect of a late afternoon/early evening bout of aerobic exercise on postprandial lipid and lipoprotein particle responses to a high-sugar meal breakfast the following day in postmenopausal women: a randomized cross-over study.

High-sugar consumption is related to dyslipidemia. How acute exercise affects postprandial lipid and lipoprotein particle responses to a high-sugar meal (HSM) in postmenopausal women is unclear. We examined the effects of a late afternoon/early evening bout of aerobic exercise on postprandial lipid and lipoprotein particle responses to a HSM breakfast the following day in 22 postmenopausal women. Subjects underwent exercise (EX) and no exercise (NE) conditions in the evening 13-16 h before the HSM breakfast consumption, in a random order. During the EX condition, subjects performed supervised aerobic exercise for 60 min at 75% of age-predicted maximum heart rate. The HSM (75.6% carbohydrate and 33% energy needs) was consumed after a 12-h fast. Serum lipids and lipoproteins were assessed at baseline and postprandially (60, 120, 180 min). Repeated measures analysis showed significantly lower area under the curve (geometric means [95% CI]) for triglycerides (TG) (2.96[2.43, 3.61] vs. 3.24[2.70, 3.88] mmol/L*hr; p = 0.049) and very low density lipoprotein particles (VLDLP) (114.6[88.2, 148.9] vs. 134.3[108.1, 166.9] nmol/L*hr; p = 0.02) during the EX versus NE condition. There were no condition effects for other variables. In conclusion, the EX versus NE condition lowered postprandial AUC for TG and VLDLP following HSM consumption in postmenopausal women.Trial Registration: ClinicalTrials.gov Identifier: NCT02919488.

Effect of ACTN3 Polymorphism on Self-reported Running Times.

Kreutzer, A, Martinez, CA, Kreutzer, M, Stone, JD, Mitchell, JB, and Oliver, JM. Effect of ACTN3 polymorphism on self-reported running times. J Strength Cond Res 33(1): 80-88, 2019-This investigation examined the effect of ACTN3 genotype on self-reported distance running personal records (PRs). Of 94 (n = 94) recreationally active men and women, 82 (f = 42, m = 40; age: 22.6 ± 4.5 years; body mass index [BMI]: 23.5 ± 3.4 kg·m) reported 1-mile running PRs, whereas 57 (f = 33, m = 24; age: 23.4 ± 5.3 years; BMI: 22.9 ± 9.3 kg·m) reported 5K running PRs. Subjects were grouped by the presence (ACTN3) or absence (ACTN3) of α-actinin-3, as well as by individual genotype (RR, RX, and XX). Among female participants, ACTN3 reported 64.5 seconds faster (p = 0.048) 1-mile PRs compared with their ACTN3 counterparts. No differences were observed when comparing 5K PRs between genotypes. Two one-sided test equivalence testing revealed that none of the effects observed when comparing ACTN3 and ACTN3 were equivalent to zero. Our study confirms a reportedly greater prevalence of XX benefits for endurance performance in females when compared with males but fails to strongly link ACTN3 genotype to endurance performance. Practitioners should continue to be cautious when using genetic information for talent identification and sport selection.

Effect of meal composition on postprandial glucagon-like peptide-1, insulin, glucagon, C-peptide, and glucose responses in overweight/obese subjects.

BACKGROUND: Glucagon-like peptide-1 (GLP-1), an incretin hormone, is released in response to food intake. It is unclear how meals high in protein (HP) and monounsaturated fat (HMF) affect GLP-1 response. PURPOSE: To examine the effect of a HP versus a HMF meal on GLP-1 response. METHODS: Twenty-four overweight/obese participants consumed two meals (HP: 31.9 % energy from protein; HMF: 35.2 % fat and 20.7 % monounsaturated fat) in a random order. Both meals contained the same energy and carbohydrate content. GLP-1, insulin, glucagon, C-peptide, and glucose were assessed from blood drawn in the fasting and postprandial states. The effect of meal condition on hormone and glucose responses and appetite ratings were assessed by repeated measures analysis. RESULTS: Statistically significant (p < 0.01) time by meal condition effect was observed on active GLP-1, total GLP-1, insulin, C-peptide, and glucagon, but not glucose (p = 0.83). Area under the curve was significantly higher during the HP versus the HMF meal conditions for active GLP-1 (23.7 %; p = 0.0007), total GLP-1 (12.2 %; p < 0.0001), insulin (54.4 %; p < 0.0001), C-peptide (14.8 %; p < 0.0001), and glucagon (40.7 %; p < 0.0001). Blood glucose was not different between the HP versus HMF conditions (-4.8 %; p = 0.11). Insulin sensitivity was higher during the HMF versus HP conditions (Matsuda index mean difference: 16.3 %; p = 0.007). Appetite ratings were not different by meal condition. CONCLUSIONS: GLP-1 and insulin responses were higher during the HP condition. However, no difference was found in blood glucose between conditions, and insulin sensitivity was higher during the HMF condition, indicating that a HMF meal may be optimal at regulating blood glucose in overweight/obese individuals without type 2 diabetes.

Velocity Drives Greater Power Observed During Back Squat Using Cluster Sets.

This investigation compared the kinetics and kinematics of cluster sets (CLU) and traditional sets (TRD) during back squat in trained (RT) and untrained (UT) men. Twenty-four participants (RT = 12, 25 ± 1 year, 179.1 ± 2.2 cm, 84.6 ± 2.1 kg; UT = 12, 25 ± 1 year, 180.1 ± 1.8 cm, 85.4 ± 3.8 kg) performed TRD (4 × 10, 120-second rest) and CLU (4 × (2 × 5) 30 seconds between clusters; 90 seconds between sets) with 70% one repetition maximum, randomly. Kinematics and kinetics were sampled through force plate and linear position transducers. Resistance-trained produced greater overall force, velocity, and power; however, similar patterns were observed in all variables when comparing conditions. Cluster sets produced significantly greater force in isolated repetitions in sets 1-3, while consistently producing greater force due to a required reduction in load during set 4 resulting in greater total volume load (CLU, 3302.4 ± 102.7 kg; TRD, 3274.8 ± 102.8 kg). Velocity loss was lessened in CLU resulting in significantly higher velocities in sets 2 through 4. Furthermore, higher velocities were produced by CLU during later repetitions of each set. Cluster sets produced greater power output for an increasing number of repetitions in each set (set 1, 5 repetitions; sets 2 and 3, 6 repetitions; set 4, 8 repetitions), and the difference between conditions increased over subsequent sets. Time under tension increased over each set and was greater in TRD. This study demonstrates greater power output is driven by greater velocity when back squatting during CLU; therefore, velocity may be a useful measure by which to assess power.

The utility of the Dementia Severity Rating Scale in differentiating mild cognitive impairment and Alzheimer disease from controls.

The current study investigated the utility of the Dementia Severity Rating Scale (DSRS) total score to identify individuals at the earliest stage of impairment (ie, mild cognitive impairment/MCI). In addition, the authors sought to investigate how well the measure correlates with an expanded battery of cognitive tests and other measures of functional abilities. Of the 320 participants included in this study, 85 were normal controls, 96 had single-domain or multiple-domain amnestic MCI, and 139 had possible or probable Alzheimer disease (AD). Each participant underwent a thorough cognitive, neurological, and physical examination. Results from this study indicated that the DSRS total scores differed significantly between the 3 groups (P<0.001) and accurately identified 81% of the control group, 60% of the MCI group, and 78% of the AD group in a post hoc discriminant analysis. When combined with a brief cognitive measure (ie, Consortium to Establish a Registry for Alzheimer's Disease Word List 5 min recall test), the DSRS accurately identified 98% of the control group, 76% of the MCI group, and 82% of the AD group. Implications for clinical practice and proposed areas of future research are discussed.

Acute response to cluster sets in trained and untrained men.

PURPOSE: In traditional sets (TRD) repetitions are performed continuously, whereas cluster sets (CLU) allow a brief rest between groups of repetitions. We investigated the acute mechanical, metabolic, and hormonal response to CLU in men. METHODS: Twelve resistance-trained (RT) and 11 untrained (UT) men performed TRD (4 × 10 repetitions with 2 min rest) and CLU [4 × (2 × 5) with 1.5 min rest between sets 30 s rest between clusters] at 70 % 1RM back squat in random order. Seven days separated trials. Average power and time under tension (TUT) were calculated. Blood was sampled pre, sets 1, 2, and 3; immediate post-exercise, 5, 15, 30, 60 min post-exercise for blood lactate, total testosterone (TT), free testosterone (FT), growth hormone (GH), and cortisol. RESULTS: CLU produced greater average power at an increasing number of repetitions over each set with greater total volume load. TUT was shorter for RT and lower for CLU in repetitions 1, 6, 7, 8. Blood lactate was higher Set 2 through 30 min in TRD. RT had higher TT; however, the time course was similar between RT and UT. TT and FT increased immediate post-exercise and remained elevated 30 min in both conditions. GH was significantly greater during TRD with a similar pattern observed in both conditions. Cortisol was significantly lower at 30 min in CLU. CONCLUSION: CLU allowed greater total volume load, shorter TUT, greater average power, similar anabolic hormonal response, and less metabolic stress. The acute response was similar despite training status.

Temperature Measurement Inside Protective Headgear: Comparison With Core Temperatures and Indicators of Physiological Strain During Exercise in a Hot Environment.

Non-invasive temperature monitoring with a sensor inside protective headgear may be effective in detecting temperatures that are associated with heat illness. The purpose was to establish the relationship between in-hardhat temperatures (Tih) and core temperature (Tc) as measured by rectal (Tre) and esophageal (Tes) probes. Thirty males (age 24.57 ± 4.32 yrs.) completed two trials: continuous submaximal exercise (CSE) and a series of high intensity 30-s sprints (HIE) with a one-minute rest between each. Exercise in both conditions was in a 36(°)C environment (40% RH) while wearing a standard hardhat with sensors mounted on the forehead that were monitored remotely. Exercise continued until voluntary termination or until Tc reached 39.5(°)C. Temperatures, heart rate, cardiorespiratory, and perceptual responses were monitored throughout. A physiological strain index (PSI) was calculated from Tc and HR. The final temperatures in the CSE condition were 38.77 ± 0.41, 38.90 ± 0.49 and 39.29 ± 0.58(°)C and in the HIE condition, final temperatures were 38.76 ± 0.37, 38.91 ± 0.47, and 39.19 ± 0.57 f (o)C for Tih, Tre, and Tes, respectively. The PSI in CSE was 9.62 ± 062, 9.18 ± 1.11, and 10.04 ± 1.05, and in the HIE condition 9.67 ± 068, 9.29 ± 0.99. and 9.86 ± 1.02 based on Tih, Tre and Tes, respectively. The general agreement between the Tih and other temperature measures along with the consistency as indicated by a low coefficient of variation (approx. 1%) in the recordings of the Tih sensors at the point of termination suggest that this device, or similar devices, may have application as a warning system for impending heat-related problems.

The effects of elapsed time after warm-up on subsequent exercise performance in a cold environment.

Athletes often compete in cold environments and may face delays because of weather or race logistics between performance of a warm-up and the start of the race. This study sought to determine, (a) whether a delay after warm-up affects subsequent time trial (TT) performance and (b) if exposure to a cold environment has an additive effect. We hypothesized that after a warm-up, 30 minutes of rest in a cold environment would negatively affect subsequent rowing and running performance. In a temperate (temp; 24° C) or cold (cold; 5° C) environment, 5 rowers (33 ± 10 years; 83 ± 12 kg) and 5 runners (23 ± 2 years; 65 ± 8 kg) performed a 15-minute standardized warm-up followed by a 5- or 30-minute rest and then performed a 2-km rowing or 2.4 km running TT. The 5-minute rest following warm-up in the temperate environment (5Temp) served as the control trial to which the other experimental trials (5Cold; 30Temp; and 30Cold) were compared. Heart rate, lactate, and esophageal (Tes) and skin (Tsk) temperatures were measured throughout. Postrest and post-TT, Tes, and Tsk were lowest in the 30Cold trials. The greatest decrement in TT performance vs. 5Temp occurred in 30Cold (-4.0%; difference of 20 seconds). This difference is considered to have practical importance, as it was greater than the reported day-to-day variation for events of this type. We conclude that longer elapsed time following warm-up, combined with cold air exposure, results in potentially important reductions in exercise performance. Athletes should consider the appropriate timing of warm-up. In addition, performance may be preserved by maintaining skin and core temperatures following a warm-up, via clothing or other means.

Fatigue during high-intensity endurance exercise: the interaction between metabolic factors and thermal stress.

The purpose of this study was to examine the effects of hot (37° C) and cool (10° C) environments on cycling time to exhaustion (TTE), pH, lactate, and core temperature (Tc). Eleven endurance-trained subjects completed 4 TTE trials: Hot 80% VO2max (H80), Cool 80% (C80), Hot 100% (H100), and Cool 100% VO2max (C100). Esophageal temperature and blood was sampled before, every 5 minutes, at exhaustion, and 3 minutes after exercise and analyzed for lactate, pH, and HCO3-. Multifactorial analysis of variance with repeated measures was used to determine differences between mean values (± SD). Time to exhaustion was shorter in H100 and C100 vs. H80 and C80 (5.64 ± 1.49 minutes, 5.83 ± 1.03 minutes, 12.82 ± 2.0 minutes, and 24.85 ± 6.0 minutes, respectively) and shorter in H80 vs. C80 (p < 0.01). The pH at exhaustion was different among all conditions (7.17 ± 0.06, 7.15 ± 0.07, 7.21 ± 0.04, and 7.24 ± 0.06 units for H100, C100, H80, and C80, respectively, p = 0.02). The Tc at exhaustion was lower in H100 and C100 (37.93 ± 0.67 and 37.62 ± 0.58° C) vs. H80 and C80 (38.54 ± 0.51° C and 38.53 ± 0.38° C) (p < 0.01). In H80 and C80, the higher Tc likely played a greater role in the termination of exercise, whereas, in H100 and C100, pH and metabolic changes may have been more important. Despite these differences, neither an upper limit for Tc nor a lower limit for pH was identified; thus, fatigue based entirely on peripheral factors was not supported, and a combination of peripheral and central processes must be considered. The practical implications of these findings are that aerobic exercise at or near VO2max may be impacted more by metabolic factors, whereas lower intensities (∼80% VO2max) may be affected more by heat stress; these differences should be considered when training for events of this type.

Preexercise energy drink consumption does not improve endurance cycling performance but increases lactate, monocyte, and interleukin-6 response.

The purpose of this study was to investigate the influence of an energy drink (ED) on cycling performance and immune-related variables. Eleven trained male cyclists (33.4 ± 8.9 years; 81 ± 7.6 kg; maximal VO2, 52 ± 3.4 ml·kg(-1)·min(-1)) consumed 500 ml of (a) ED (2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 56 g carbohydrate [CHO], and B vitamins), (b) cola matched for caffeine and CHO (CC), or (c) flavored placebo (PL: sparking water and flavoring) 50 minutes before racing in a randomized, crossover design. Performance was measured as time to complete (TTC) a 25-mile simulated road race. Blood was collected at baseline, 30 minutes after drink consumption, during exercise at miles 5 (M5), 15 (M15), and immediately (POEX) and 30 minutes (30minPO) after exercise. TTC was not different (p > 0.05) among trials (ED, 68.6 ± 2.7; CC, 68.9 ± 3.8; PL, 69.6 ± 3.8 minutes). Consumption of CC and ED elicited a mild hypoglycemia elicited a mild hypoglycemia during cycling. POEX interleukin-6 (IL-6) was greatest after ED, whereas CC IL-6 was greater than PL (10.2 ± 1.6, 6.7 ± 0.6, and 4.8 ± 0.7 pg·ml(-1), respectively; p < 0.001). Cycling increased leukocyte number in all conditions with ED leukocyte number greater than that of PL at M15 (9.8 ± 0.6, 8.5 ± 0.3 × 10(6) cells·mL(-1)). Energy drink induced an earlier recruitment of monocytes to the blood stream than CC. Mean fat oxidation was greater in PL compared with CC (0.43 ± 0.06 and 0.28 ± 0.04 g·min(-1); p = 0.033) but did not differ between ED (0.32 ± 0.06) and PL. Lactate was higher in ED compared with CC and PL at M5 and M15 (p = 0.003), but there was no significant influence of either ED or CC on performance. Carbohydrate and caffeine consumption before endurance cycling significantly increased the IL-6 release and leukocytosis, and the additional ingredients in ED seem to have further augmented these responses.

Ingestion of carbohydrate during recovery in exercising people.

PURPOSE OF REVIEW: The primary focus of this brief review is to describe the effect of carbohydrate (CHO) supplementation alone or in combination with protein on two responses during postexercise recovery that are not specifically related to the usual emphasis on glycogen resynthesis; that is, rapid postexercise rehydration, and recovery from exercise-induced muscle damage. RECENT FINDINGS: Evidence from postexercise rapid rehydration studies suggests that the addition of CHO to a rehydration solution may increase the rate of fluid restoration compared with water placebo. Adding protein to a CHO solution may further accentuate the beneficial effects. An additional postexercise concern for active individuals is the development of postexercise muscle soreness, a response that is pronounced with novel, eccentric exercise. Ingestion of CHO supplements, especially those combined with protein may help to minimize the exercise-induced muscle damage that is accompanied by muscle soreness, and reduced muscle function. SUMMARY: The practical implications of these findings are that CHO supplementation, especially in combination with protein, can enhance the rate of recovery relative to fluid balance and muscle damage; thus, these nutritional interventions should be considered for purposes in addition to the usual focus on glycogen resynthesis.

Exercise-associated hyponatremia: the influence of pre-exercise carbohydrate status combined with high volume fluid intake on sodium concentrations and fluid balance.

To evaluate the effect of hydration and carbohydrate (CHO) status on plasma sodium, fluid balance, and regulatory factors (IL-6 & ADH) during and after exercise; 10 males completed the following conditions: low CHO, euhydrated (fluid intake = sweat loss) (LCEH); low CHO, dehydrated (no fluid) (LCDH); high CHO, euhydrated (HCEH); and high CHO, dehydrated (HCDH). Each trial consisted of 90-min cycling at 60% VO(2) max in a 35°C environment followed by 3-h rehydration (RH). During RH, subjects received either 150% of sweat loss (LCDH & HCDH) or an additional 50% of sweat loss (LCEH and HCEH). Blood was analyzed for glucose, IL-6, ADH, and Na(+). Post-exercise Na(+) was greater (p < 0.001) for LCDH and HCDH (141.7 + 0.72 and 141.6 + 0.4 mM) versus LCEH and HCEH (136.4 + 0.6 and 135.9 + 0.3 mM). Post-exercise IL-6 was similar in all conditions, and post-exercise ADH was greater (p = 0.01) in dehydrated versus euhydrated conditions. The rate of urine production was greater in HCEH (7.59 + 3.0 mL/min) compared to all other conditions (3.86 + 2.2, 5.29 + 3.1, and 2.96 + 1.1 mL/min for LCDH, LCEH, and HCDH, respectively). Despite CHO and hydration manipulations, no regulatory effects of IL-6 and ADH on plasma [Na(+)] were observed. With euhydration during exercise and additional fluid consumed during recovery, a high-CHO status increased urinary output during recovery, and it decreased the frequency of hyponatremia (Na(+) < 135 mM). Therefore, a high-CHO status may provide some protection against exercise-associated hyponatremia.

Resistance and aerobic exercise: the influence of mode on the relationship between IL-6 and glucose tolerance in young men who are obese.

Regular exercise lowers indicators of disease risk including some inflammatory cytokines; however, the relationship between different modes of acute exercise, cytokine levels, and subsequent glucose tolerance is unclear. The purpose was to determine the effects of resistance (RES) and aerobic (AER) exercises on interleukin-6 (IL-6) and its association with glucose tolerance 24 hours after exercise. After testing for 1 repetition maximum (1RM) and VO2peak, 10 obese (body mass index > 30 kg · m(-2)), untrained men aged 18-26 years completed 3 protocols: 60 minutes of RES, AER, and a resting (CON) condition. The RES was 2 sets of 8 repetitions and a third set to fatigue at 80% 1RM of 8 lifts using all major muscle groups. The AER was 60 minutes of cycling at 70% of VO2peak. On day 1, subjects completed the 60-minute exercise or resting protocol, and on day 2, they completed an oral glucose tolerance test (OGTT). Blood was collected before and after exercise, at 2 and 7 hour postexercise, and before and every 30 minutes during the OGTT and was analyzed for IL-6, glucose and insulin. Postexercise IL-6 was greater in RES (8.01 ± 2.08 pg · mL(-1)) vs. in AER (4.26 ± 0.27 pg · mL(-1)), and both were greater than in CON (1.61 ± 0.18 pg · mL(-1)). During the OGTT, there were no differences in glucose or insulin between conditions for single time points or as area under the curve. The RES caused greater IL-6 levels immediately after exercise that may be related to the greater active muscle mass compared to AER. Neither exercise produced enhanced glucose removal compared to control; thus, despite the greater elevation in IL-6 in RES, for these exercise conditions and this population, this cytokine did not influence glucose tolerance.

Functional Oligomeric Forms of Uncoupling Protein 2: Strong Evidence for Asymmetry in Protein and Lipid Bilayer Systems.

Stoichiometry of uncoupling proteins (UCPs) and their coexistence as functional monomeric and associated forms in lipid membranes remain intriguing open questions. In this study, tertiary and quaternary structures of UCP2 were analyzed experimentally and through molecular dynamics (MD) simulations. UCP2 was overexpressed in the inner membrane of Escherichia coli, then purified and reconstituted in lipid vesicles. Structure and proton transport function of UCP2 were characterized by circular dichroism (CD) spectroscopy and fluorescence methods. Findings suggest a tetrameric functional form for UCP2. MD simulations conclude that tetrameric UCP2 is a dimer of dimers, is more stable than its monomeric and dimeric forms, is asymmetrical and induces asymmetry in the membrane's lipid structure, and a biphasic on-off switch between the dimeric units is its possible mode of transport. MD simulations also show that the water density inside the UCP2 monomer is asymmetric, with the cytoplasmic side having a higher water density and a wider radius. In contrast, the structurally comparable adenosine 5'-diphosphate (ADP)/adenosine 5'-triphosphate (ATP) carrier (AAC1) did not form tetramers, implying that tetramerization cannot be generalized to all mitochondrial carriers.

Influence of commonly employed resistance exercise protocols on circulating IL-6 and indices of insulin sensitivity.

The purpose of this project was to examine the influence of resistance exercise (RE) intensities, resulting in different total volume loads on circulating interleukin-6 (IL-6), insulin and glucose response (IGR) to a carbohydrate feeding (CHO), and whether RE-induced IL-6 was associated with postexercise IGR. Fourteen men (21.7 +/- 1.7 years, 83 +/- 14.2 kg), performed 2 RE sessions (low-intensity resulting in high volume [65% 1-repetition maximum (1RM)], LO; high intensity resulting in low volume [85% 1RM], HI); and a nonexercise control trial (CON). Resistance exercise included 3 sets (LO = 12 reps, 12 reps, and failure; HI = 8 reps, 8 reps, and failure) of 8 exercises. Blood was obtained pre- (PR) and post (PO) exercise, and 6 hours postexercise (6H). Twenty-three hours after RE or CON, participants consumed 100 g dextrose (CHO) beverage. Blood was collected before (0 minutes) and 60 minutes after CHO (n = 6, phase 1) or every 30 minutes for a 2-hour oral glucose tolerance test (n = 8; phase 2). Circulating IL-6, insulin, and glucose were analyzed via enzyme-linked immunosorbent assay, radioimmunoassay, and enzymatic methods, respectively. Total volume load was higher in LO (17,729 +/- 1,466 kg) compared with HI (13,160 +/- 1,097 kg; p < 0.001). Postexercise IL-6 was elevated (p = 0.003) in LO and HI compared with CON (7.4 +/- 1.3, 5.2 +/- 0.7, and 2.5 +/- 0.7 pg.mL, respectively), with LO IL-6 greater than HI. Areas under the curve for glucose (p = 0.081; CON: 741 +/- 46, LO: 690 +/- 28, and HI: 660 +/- 21 mM.min) and insulin (p = 0.075; CON: 6,818 +/- 1,018, LO: 5,056 +/- 869, and HI: 5,405 +/- 1,076 microIU.mL) were not different among trials (n = 8). When 0- and 60-minute values were compared (n = 14), insulin was lower at 60 minutes in LO and HI compared with CON (55 + 9.1, 83 +/- 13, 105 +/- 13 microIU.mL, respectively) with LO insulin being lower than HI (p < 0.001). No relationship was observed between PO IL-6 and IGR, but PR IL-6 was negatively related to both PR (r = -0.043, p < 0.05) and 60 minutes (r = -0.59, p < 0.01) glucose (n = 14). These results indicate that TVL contributes to RE-induced IL-6 release and that TVL may be more important than RE intensity when improvements in glucose tolerance or IS are the goal.

Effect of acute exercise on postprandial endothelial function in postmenopausal women: a randomized cross-over study.

High-sugar intake may cause endothelial dysfunction. It is unknown if a bout of aerobic exercise improves endothelial dysfunction caused by a high-sugar meal in postmenopausal women. This study evaluated if prior aerobic exercise attenuates postprandial endothelial dysfunction in postmenopausal women. Twenty-two postmenopausal women (age [mean±SD]: 60.4±6.5 years; % body fat: 40.3%±7.5%) underwent an exercise (EX) or no exercise (NE) condition, in a random order, 13-16 hours prior to the high-sugar meal consumption. The EX condition included a 60 min bout of supervised aerobic exercise at 75% of age-predicted maximum heart rate. The high-sugar meal, consumed after a 12-hour fast, contained 33% of the subjects' daily energy needs, and 75.6% energy from carbohydrates. Flow-mediated dilation (FMD) and blood concentrations of glucose, insulin, endothelin-1 (ET-1), and nitric oxide (NO) were assessed at baseline and 60 min, 120 min, and 180 min postprandially. Repeated measures analysis test showed that there were no condition by time interaction or condition effects for FMD, glucose, insulin, or NO. There was a significant condition by time interaction but no condition effect for ET-1. Area under the curve was also not different by condition for insulin sensitivity or the above variables. In conclusion, prior aerobic exercise compared with NE did not affect FMD, blood glucose, insulin, ET-1 or NO concentrations, or insulin sensitivity following a high-sugar meal in postmenopausal women. Future studies should look at the effect of different EX intensities on meal-induced endothelial dysfunction in this population. Trial Registration: ClinicalTrials.gov Identifier: NCT02919488.

The Effects of High-Protein and High-Monounsaturated Fat Meals on Postprandial Lipids, Lipoprotein Particle Numbers, Cytokines, and Leptin Responses in Overweight/Obese Subjects.

BACKGROUND: Obesity is linked to dyslipidemia, proinflammatory state, and hyperleptinemia. The influence of high-protein (HP) versus high-monounsaturated fat (HMF) meals on postprandial lipids, lipoprotein particle numbers, cytokines, and leptin responses in overweight/obese (OW/O) subjects is unknown. METHODS: Twenty-four OW/O participants consumed an HP (31.9% energy from protein) and HMF (35.2% fat and 20.7% monounsaturated fat) meal, of similar energy/carbohydrate content, in a random order. The outcome variables were assessed from blood samples collected in fasted and postprandial (3 hr) states. RESULTS: Repeated measures analysis found significant (P < 0.05) meal condition by time interactions for triglycerides (TGs), very low-density lipoprotein particles (VLDLP), total high-density lipoprotein particles (T-HDLP), and the ratio of large-buoyant high-density lipoprotein 2b (LB-HDL2b) to T-HDLP, and meal effect on small-dense HDLP (SD-HDLP). Comparison of HP versus HMF condition showed significantly lower TG at 120 min [geometric mean (95% confidence interval, CI): 148 (125-175) vs. 194 (164-230) mg/dL] and 180 min [167 (138-203) vs. 230 (189-278) mg/dL] and VLDLP at 180 min [70.0 (58.2-84.3) vs. 88.0 (73.1-106) nmol/L]. HP versus HMF condition showed significantly lower LB-HDL2b/T-HDLP at 180 min [mean difference (95% CI): 0.021 (0.004-0.038)], and higher T-HDLP [671 (263-1079) nmol/L] and SD-HDLP [606 (292-920) nmol/L] at 120 min. Area under the curve was significantly lower for TG and higher for T-HDLP, SD-HDLP, and small-dense LDL III (SD-LDL III) in the HP condition. Cytokines and leptin were not different between conditions. CONCLUSION: OW/O subjects had lower TG and VLDLP, but less favorable SD-LDL III, SD-HDLP, and LB-HDL2b/T-HDLP ratio responses to the HP versus HMF meals.

Behavioral immune system activity predicts downregulation of chronic basal inflammation.

Here, we present a mechanistically grounded theory detailing a novel function of the behavioral immune system (BIS), the psychological system that prompts pathogen avoidance behaviors. We propose that BIS activity allows the body to downregulate basal inflammation, preventing resultant oxidative damage to DNA and promoting longevity. Study 1 investigated the relationship between a trait measure of pathogen avoidance motivation and in vitro and in vivo proinflammatory cytokine production. Study 2 examined the relationship between this same predictor and DNA damage often associated with prolonged inflammation. Results revealed that greater trait pathogen avoidance motivation predicts a) lower levels of spontaneous (but not stimulated) proinflammatory cytokine release by peripheral blood mononuclear cells (PBMCs), b) lower plasma levels of the proinflammatory cytokine interleukin-6 (IL-6), and c) lower levels of oxidative DNA damage. Thus, the BIS may promote health by protecting the body from the deleterious effects of inflammation and oxidative stress.

Heat shock protein (HSP-72) levels in skeletal muscle following work in heat.

INTRODUCTION: Acute bouts of heat stress and exercise have been shown to independently increase heat shock protein levels; however, the combination of these two stressors on HSP-72 expression in human skeletal muscle has not been established. The purpose of this study was to determine the effect of a bout of exercise in the heat on HSP-72 expression. METHODS: There were eight recreationally active men (Age = 26.4 +/- 3.1 yr, V(O2)peak = 4.01 +/- 0.25 L min(- 1)) who completed two 30-min bouts of cycle ergometry at 75% of V(O2)peak in a hot (39 degrees C; RH 30%) and cold (9 degrees C; RH 61%) environment. Muscle biopsies were obtained from the vastus lateralis prior to, 6 h post, and 24 h post-exercise to measure HSP-72 protein. Core rectal temperature (Tc), average skin temperature (T(SK)), intramuscular temperature (T(IM)), heart rate (HR), oxygen uptake (V(O2)), sweat rate (SR), and plasma cortisol were measured to determine thermal loads. RESULTS: No significant interactions were present between V(O2) (2.80 +/- 0.2 vs. 2.65 +/- 0.1 L min(-1)) or plasma cortisol (27.1 +/- 2 vs. 19.2 +/- 4 microg dl(-1)) when comparing HT and CD. HR (184 +/- 5 vs. 159 +/- 7 bpm), T(IM) (40.7 +/- 0.2 vs. 40.0 +/- 0.2 degrees C), Tc (38.3 +/- 0.2 vs. 37.9 +/- 0.1 degrees C), T(SK) (36.7 +/- 0.2 vs. 29.6 +/- 0.8 degrees C), and SR (2.0 +/- 0.2 vs. 1.2 +/- 0.2 L h(-1)) were significantly greater when comparing HT and CD. HSP-72 was not altered as a result of either treatment (4.04 +/- 0.87 vs. 2.91 +/- 1.58 ng microg(-1) protein for HT and CD at 6 h post-exercise). DISCUSSION: Exercise in the heat produced a greater thermal load than exercise in the cold; however, no significant increases in HSP-72 were seen when comparing hot and cold conditions.