A framework of transient hypercapnia to achieve an increased cerebral blood flow induced by nasal breathing during aerobic exercise.

During exercise, cerebral blood flow (CBF) is expected to only increase to a maximal volume up to a moderate intensity aerobic effort, suggesting that CBF is expected to decline past 70 % of a maximal aerobic effort. Increasing CBF during exercise permits an increased cerebral metabolic activity that stimulates neuroplasticity and other key processes of cerebral adaptations that ultimately improve cognitive health. Recent work has focused on utilizing gas-induced exposure to intermittent hypoxia during aerobic exercise to maximize the improvements in cognitive function compared to those seen under normoxic conditions. However, it is postulated that exercising by isolating breathing only to the nasal route may provide a similar effect by stimulating a transient hypercapnic condition that is non-gas dependent. Because nasal breathing prevents hyperventilation during exercise, it promotes an increase in the partial arterial pressure of CO2. The rise in systemic CO2 stimulates hypercapnia and permits the upregulation of hypoxia-related genes. In addition, the rise in systemic CO2 stimulates cerebral vasodilation, promoting a greater increase in CBF than seen during normoxic conditions. While more research is warranted, nasal breathing might also promote benefits related to improved sleep, greater immunity, and body fat loss. Altogether, this narrative review presents a theoretical framework by which exercise-induced hypercapnia by utilizing nasal breathing during moderate-intensity aerobic exercise may promote greater health adaptations and cognitive improvements than utilizing oronasal breathing.

Effects of Static Contemporary Western Yoga vs. a Dynamic Stretching Exercise Program on Body Composition, Balance, and Flexibility.

ABSTRACT: Chapman-Lopez, TJ, Moris, JM, Petty, G, Timon, C, and Koh, Y. Effects of static contemporary western yoga vs. a dynamic stretching exercise program on body composition, balance, and flexibility. J Strength Cond Res 37(5): 1064-1069, 2023-Essentrics is a dynamic full-body stretching workout, which has recently earned its popularity in the field of yoga because of its potential for improvement in balance, flexibility, and weight loss while adding enjoyment to the workout without any discomfort and pain. However, the effects of Essentrics on overall health have not been well studied, particularly in a younger, physically healthy population. Thirty-five subjects (27 females and 8 males, age = 20.4 ± 0.2 years, and body mass index = 22.58 ± 0.55 kg·m-2) were assigned to 2 groups-contemporary western yoga (CWY, n = 20) and Essentrics (ESS, n = 15). Each group met 3 times per week for a total of 45-50 minutes per day for 6 weeks. Anthropometric measurements, body composition (dual-energy x-ray absorptiometry), flexibility (sit-and-reach), and balance (lower extremity Y-balance) were assessed before and after the 6-week program. The balance test included 3 reaches (anterior, posteromedial [PM], and posterolateral [PL] and composite reach distance). Each reach was averaged for the right and left sides and then normalized to leg length. Data were analyzed using an analysis of variance with repeated measures (p ≤ 0.05), and a post hoc test was performed for any significant interactions. There were no significant group differences between CWY and ESS in balance and flexibility. Following the 6-week yoga programs, balance was improved as follows: PM (87.13 ± 11.64 cm to 92.25 ± 9.91 cm, p = 0.001), PL (82.88 ± 11.28 to 88.62 ± 9.62 cm, p = 0.002), composite reach distance (CRD) (225.96 ± 27.17 to 238.26 ± 22.98 cm, p = 0.001), normalized PM (98.31 ± 11.68 to 104.27 ± 11.14%, p = 0.001), normalized PL (93.60 ± 11.98 to 100.15 ± 10.70%, p = 0.001), and normalized CRD (255.12 ± 27.89 to 269.21 ± 25.07%, p = 0.001). Flexibility was also improved from 51.42 ± 8.24 to 53.38 ± 7.04 cm (p = 0.010) following the 6-week workout programs. Total body fat percentage was significantly reduced only in the CWY group (24.44 ± 6.73 to 23.51 ± 6.32%, p = 0.002). Regardless of the type of stretching workout, both dynamic and static workouts improved flexibility and balance. Thus, individuals seeking to improve balance and flexibility can benefit from either dynamic or static yoga program.

One-year Aerobic Interval Training Improves Endothelial Dysfunction in Patients with Atrial Fibrillation: A Randomized Trial.

Objective To evaluate the effects of one-year aerobic interval training on endothelial dysfunction in patients with atrial fibrillation. Methods Seventy-four patients with atrial fibrillation (53 men, 21 women; mean age 63±6 years old) were randomized into a 1-year continuous aerobic interval training (CT), 6-month detraining after 6 months of aerobic interval training (DT), or medical treatment only (MT) group. Aerobic interval training was performed 3 times a week for 1 year or 6 months, with an exercise intensity of 85-95% of the peak heart rate. The primary outcome was a change in biomarkers of endothelial dysfunction from baseline at six months or at the one-year follow-up. Results Six-month aerobic interval training reduced von Willebrand factor (CT: 103.7±30.7 IU/dL and DT: 106±31.2 IU/dL vs. MT: 145±47.7 IU/dL, p=0.044). Improvements were maintained with continuous aerobic interval training; however, the values increased again to the baseline levels upon detraining (CT: 84.3±39.1 IU/dL vs. DT: 122.2±27.5 IU/dL and MT: 135.9±50.4 IU/dL, p=0.002). Interleukin 1 beta levels decreased after 6 months of aerobic interval training (CT: 0.59±0.1 pg/mL and DT: 0.63±0.09 pg/mL vs. MT: 0.82±0.28 pg/mL, p=0.031), and the improvement was maintained with continuous aerobic interval training and even after detraining (CT: 0.58±0.08 pg/mL and DT: 0.62±0.09 pg/mL vs. MT: 0.86±0.28 pg/mL, p=0.015). Conclusion One-year aerobic interval training improves endothelial dysfunction in patients with atrial fibrillation and is primarily associated with the reduction in circulating thrombogenic and pro-inflammatory factors. A definitive way to sustain these improvements is the long-term continuation of aerobic training.

The Effects of Medium-Chain Triglyceride Oil Supplementation on Endurance Performance and Substrate Utilization in Healthy Populations: A Systematic Review.

Background: The use of medium-chain triglyceride (MCT) oil has increased due to its potential for therapeutic and ergogenic properties. Although recent evidence has suggested that MCT oil supplementation may lead to an improvement in endurance and substrate utilization, contradicting studies have reported the ergogenic benefits of MCT oil toward exercise performance. Methods: An extensive systematic review was conducted to assess the role of MCT oil as an ergogenic aid in exercise performance. Moreover, this study examined any alterations in substrate utilization and various physiological components while using MCT oil. The databases searched in this review were PubMed, Embase, CINAHL, and the Cochrane Library. Results: Most studies reported that MCT oil did not improve exercise performance and had no effect on respiratory exchange ratio, glucose concentration, fat and carbohydrate oxidation, and lactate concentration. Although ketones were increased when supplementing with MCTs, most studies demonstrated that the body could not utilize the MCT oil-induced ketones as its primary energy source during an acute bout of endurance exercise. Thirty grams of MCTs seems to be the safe maximal dosage to minimize adverse reactions during or after exercise. Conclusion: MCT oil showed very little to no ergogenic effects on exercise performance and substrate utilization in healthy populations. Future research is needed to examine the effects of long-term intake of MCT oil alongside various diets, perhaps a ketogenic diet, on exercise performance within different sports/exercises in a variety of populations.

Aerobic Performance Detriments while Wearing a Face Mask Diverge Among Males and Females.

The current study examined the impact of wearing a face mask (FM) at rest and while exercising on cardiorespiratory variables and aerobic performance between males and females. Nine males (21.4 ± 0.5 yr) and 9 females (21.8 ± 3.6 yr) performed a pulmonary function test and a graded maximal exercise test (GXT) on a treadmill with an FM and without an FM in random order. During the GXT, cardiorespiratory variables were measured at different exercise intensities (rest, 40%, 55%, 70%, 80%, 100% of VO2max) and during recovery. Regardless of sex, both males and females significantly (p = .01) reduced their resting pulmonary functions, including forced vital capacity (18.7% and 19.6%, respectively), forced expiratory volume in one second (43.9% and 45.7%, respectively), and peak expiratory flow (85.2% and 87.5%, respectively) with an FM. During the GXT, both VO2 and ventilation (VE) in males were significantly (p < .01) lower with an FM only at 100% of VO2max, while females showed a significantly (p < .01) lower VO2, VE, and tidal volume (Vt) with an FM throughout the entire GXT. The partial pressure of exhaled CO2 was significantly (p = .02) higher at 100% of VO2max with an FM only in males. Although wearing an FM reduced resting pulmonary functions and the maximal aerobic performance for both males and females, there was a clear sex-specific response during the GXT, indicating that females were less capable to adapt to the pulmonary obstruction induced by wearing an FM.

Nutrient-Based Appetite Regulation.

Regulation of appetite is dependent on crosstalk between the gut and the brain, which is a pathway described as the gut-brain axis (GBA). Three primary appetite-regulating hormones that are secreted in the gut as a response to eating a meal are glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), and peptide YY (PYY). When these hormones are secreted, the GBA responds to reduce appetite. However, secretion of these hormones and the response of the GBA can vary depending on the types of nutrients consumed. This narrative review describes how the gut secretes GLP-1, CCK, and PYY in response to proteins, carbohydrates, and fats. In addition, the GBA response based on the quality of the meal is described in the context of which meal types produce greater appetite suppression. Last, the beneficiary role of exercise as a mediator of appetite regulation is highlighted.

Endurance exercise-mediated metabolic reshuffle attenuates high-caloric diet-induced non-alcoholic fatty liver disease.

INTRODUCTION AND AIM: Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases in the United States. Metabolic distress (obese diabetes) is the main causative element of NAFLD. While there is no cure for NAFLD, endurance exercise (EEx) has emerged as a therapeutic strategy against NAFLD. However, mechanisms of EXE-induced hepatic protection especially in female subjects remain unidentified. Thus, the aim of the study is to examine molecular mechanisms of EXE-induced hepatic protection against diet-induced NAFLD in female mice. MATERIAL AND METHODS: Nine-week-old female C57BL/6J mice were randomly divided into three groups: normal-diet control group (CON, n=11); high-fat diet/high-fructose group (HFD/HF, n=11); and HFD/HF+EEx group (HFD/HF+EEx, n=11). The mice assigned to HFD/HF and HFD/HF+EEx groups were fed with HFD/HF for 12 weeks, after which the mice assigned to the EEx group began treadmill exercise for 12 weeks, with HFD/HF continued. RESULTS: EEx attenuated hepatic steatosis, reduced de novo lipogenesis (reduction in ATP-Citrate- Lyase and diacylglycerol-O-acyltransferase 1), and enhanced mitochondrial biogenesis and fatty-acid activation (oxidative phosphorylation enzymes and Acyl-CoA synthetase1). Also, EEx prevented upregulation of gluconeogenic proteins (glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphatase, and phosphoenolpyruvate-carboxykinase1), premature senescence (suppression of p53, p22, and p16, tumor-necrosis-factor-α, and interleukin-1ß, and oxidative stress), and autophagy deficiency. Furthermore, EXE reversed apoptosis arrest (cleaved cysteine-dependent-aspartate-directed protease3 and Poly-(ADP-ribose)-polymerase1). CONCLUSION: EEx-mediated reparations of metabolic and redox imbalance (utilization of pentose phosphate pathway), and autophagy deficiency caused by metabolic distress critically contribute to preventing/delaying severe progression of NAFLD. Also, EEx-induced anti-senescence and cell turnover are crucial protective mechanisms against NAFLD.

A 3-Week, Low-Carbohydrate, High-Fat Diet Improves Multiple Serum Inflammatory Markers in Endurance-Trained Males.

ABSTRACT: Waldman, HS, Heatherly, AJ, Killen, LG, Hollingsworth, A, Koh, Y, and O'Neal, EK. A three-week, low-carbohydrate, high-fat diet improves multiple serum inflammatory markers in endurance-trained males. J Strength Cond Res 36(9): 2502-2508, 2022-This study examined the effects of a low-carbohydrate, high-fat diet (LCHF) on inflammatory marker responses in middle-aged endurance athletes. Eight male runners maintained their habitual mixed diet (HMD) in the first phase of the study before switching to a noncalorically restricted LCHF diet (∼70% of kcals from fat; carbohydrate <50 g) for 3 weeks. Subjects completed a 50-minute fixed pace treadmill running protocol in a hot environment, followed by a 5-km outdoor time trial. Fasting serum samples were collected immediately after exercise and heat stress restriction, and again 24 hours after the exercise/heat stressor. Thirty inflammation markers were assessed using the multiplex flow immunoassay technique. Seven markers (BAFF/TNFSF-13, sCD30/TNFRSF8, sCD163, Chitinase3-like1, gp130SIL-6Rß, sTNFR-1, and sTNFR-2) reached statistical significance ( p < 0.05) favoring LCHF before exercise, and sCD30/TNFRSF8 favored ( p < 0.05) LCHF before (HMD = 459 ± 111; LCHF = 296 ± 100) and after (HMD = 385 ± 104; LCHF = 285 ± 104 pg·ml -1 ) exercise. Although the current dietary intervention was short in duration, LCHF seems to offer some protection against multiple chronic inflammation markers for physically active men between ages 30 and 50 years.

Non-nutritive Sweeteners and Their Associations with Obesity and Type 2 Diabetes.

Evidence linking the excessive consumption of nutritive sweeteners (NS) to adverse metabolic health outcomes has led to an increase in consumption of non-nutritive sweeteners (NNS), particularly among the obese and individuals with diabetes. NNS are characterized by having zero-to-negligible caloric load, while also having a sweet taste. They are utilized as a replacement for traditional NS to reduce energy intake and to limit carbohydrate-related negative health outcomes. However, recent studies have suggested that NNS may actually contribute to the development or worsening of metabolic diseases, including metabolic syndrome, obesity, type 2 diabetes, and cardiovascular disease. Thus, it is imperative to understand the NNS efficacy and the relationship between NNS and metabolic diseases.

Effects of a 3-week High-Fat-Low-Carbohydrate Diet on Lipid and Glucose Profiles in Experienced, Middle-age Male Runners.

This study examined glucose and lipid marker responses following a 3-week, ad libitum low-carbohydrate-high-fat diet (LCHF; ~70% kcals from fat, <50 g/day of net carbohydrates) versus the habitual mixed macronutrient diet (HMD) of eight middle-age, trained male runners (40 ± 10 years; V̇O2peak = 49 ± 4 mL·kg-1·min-1). Blood was drawn at 0600 from an antecubital vein after an overnight fast under conditions of no exercise/heat stress (NEXH; 48 h of restriction from intense exercise) or 24-h after exercise/heat stress (EXH; 60 min run in hot conditions plus 5-km time trial) for both dietary conditions. Glucose improvement during LCHF approached but did not reach statistical significance (p = 0.07). Pre-exercise triacylglycerol did not differ between treatments but decreased > 20 mg/dL (p < 0.05) for both treatments from NEXH to EXH (HMD = 42 ± 16; LCHF = 35 ± 21 mg/dL). Main effects for diet were exhibited for HDL-C during NEXH and EXH (HMD = 48 ± 10 and 50 ± 11; LCHF = 57 ± 13 and 60 ± 13 mg/dL), and LDL-C also increased (p = 0.02) by ~20 mg/dL for LCHF at both collection points resulting in ~30 mg/dL greater total cholesterol for LCHF before and 24-h after exercise (p < 0.05). A 3-week, ad libitum LCHF did not elicit significant negative cardiovascular disease risk in male runners 30-50 years of age with healthy pre-intervention lipid and glucose marker status.

Cell adhesion molecules and exercise.

BACKGROUND: An extensive systematic review was undertaken in the current literature in order to explore the role of different types and intensities of exercise in cell adhesion molecules (CAMs), one of the markers of vascular inflammation, endothelial dysfunction, and atherosclerosis. METHODS: Twenty-eight qualifying studies were extensively reviewed to examine the effects of different intensities (low-to-moderate vs. high) and types (aerobic vs. resistance) of exercise on intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and selectins. RESULTS: Low-to-moderate intensity aerobic exercise favorably decreased CAMs in a variety of subject populations, while CAMs momentarily increased immediately following high-intensity aerobic exercise, which then returned to the pre-exercise level within several hours post-exercise. Resistance exercise, regardless of its intensity, did not significantly influence CAMs. CONCLUSION: It is evident that the responses of CAMs are dependent upon the type and intensity of exercise performed. The most common, favorable outcome was a decrease in CAMs following low-to-moderate intensity aerobic exercise, while high-intensity aerobic exercise showed a short-lived, momentary increase in CAMs, which returned to the pre-exercise level within a few hours post-exercise. Resistance exercise, regardless of its intensity, neither significantly increased nor decreased CAMs. Future studies should focus more on the role of exercise in both soluble and membrane-bound CAMs as well as proinflammatory cytokines related to atherosclerosis in order to develop specific exercise programing that can effectively improve vascular inflammation and endothelial health.

Exercise-induced changes in stress hormones and cell adhesion molecules in obese men.

PURPOSE: The current study examined the relationship between exercise-induced changes in stress hormones (epinephrine, norepinephrine, and cortisol) and vascular inflammatory markers (soluble intracellular adhesion molecule-1 [sICAM-1], soluble endothelial selectin [sE-selectin], and soluble vascular adhesion molecule-1 [sVCAM-1]) in obese men over a 24-hour period following exercise at lower and higher intensity. PATIENTS AND METHODS: Fifteen physically inactive, obese, college-aged men performed a single bout of cycling exercise at lower and higher intensities (lower intensity: 50% of maximal heart rate, and higher intensity: 80% of maximal heart rate) in random order. Overnight fasting blood samples were collected at baseline, immediately postexercise (IPE), 1-hour PE (1-h PE), and 24-hour PE. Changes in stress hormones and inflammatory markers were analyzed with a repeated-measures analysis of variance using Bonferroni multiple comparisons and a linear regression analysis (p<0.05). RESULTS: sICAM-1, sVCAM-1, epinephrine, and norepinephrine did not change over time, while sE-selectin was significantly lower at 1-h PE (10.25±1.07 ng/mL, p=0.04) than at baseline (12.22±1.39 ng/mL). Cortisol and sICAM-1 were negatively related at 1-h PE following lower-intensity exercise (r2=0.34, p=0.02), whereas cortisol and sVCAM-1 were positively related at IPE following higher-intensity exercise (r2=0.36, p=0.02). CONCLUSION: Regardless of intensity, an acute bout of aerobic exercise may lower sE-selectin in sedentary obese men. Responses of cortisol are dependent on exercise intensity, and cortisol may be a key stress hormone playing a major role in regulating sICAM-1 and sVCAM-1.

Oxidized Low-Density Lipoprotein and Cell Adhesion Molecules Following Exercise Training.

Elevated oxidized low-density lipoprotein (ox-LDL) and cell adhesion molecules are associated with inflammation and atherosclerosis. The role of exercise in circulating ox-LDL, enzyme mediators, and cell adhesion molecules are not clearly understood in obesity. As a randomized controlled design, 27 obese (BMI>30 kg/m2) sedentary men (N=13) and women (N=14) were randomly assigned to either an exercise (N=15) or a control (N=12) group. The exercise group performed a 60-min supervised treadmill exercise at moderate intensity (70% of HRmax) for 3 days per week for 4 weeks, while the control group did not exercise. Overnight fasting blood samples were collected before and after the study period to analyze serum lipids, lipoprotein-cholesterol, ox-LDL, 12- and 15-lipoxygenases, myeloperoxidase (MPO), and soluble vascular cell adhesion molecules-1 and intercellular adhesion molecule-1. Moderate-intensity exercise training lowered both ox-LDL (from 44.76±1.99 to 38.51±1.99 U/L, p=0.032) and MPO (from 31.48±2.20 to 23.09±2.20 ng/mL, p=0.010), without significantly altering body weight, other parameters of serum lipids and lipoproteins, or soluble cell adhesion molecules. Moderate intensity exercise training reduced the levels of ox-LDL and MPO, indicating a reduced risk for developing CVD and additional protection to the possible metabolic complications associated with obesity.

Responses of inflammatory cytokines following moderate intensity walking exercise in overweight or obese individuals.

This study investigated the effects of a 4-week moderate intensity walking exercise on the levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and adiponectin in overweight or obese individuals. Twenty-seven (13 men and 14 women) physically inactive, over-weight or obese (body mass index>25.0 kg/m2) individuals participated in the study. Each participant was randomly assigned to either exercise (EX; n=15) or control (CON; n=12) group. The EX group performed moderate intensity walking exercise on a treadmill for 60 min at 70% of maximal heart rate for 4 weeks (3 days/wk). Overnight fasting blood samples were collected before and after the study period (Pre and Post) to analyze the levels of pro-/anti-inflammatory cytokines such as CRP, TNF-α, and adiponectin. CRP and adiponectin as well as body weight and body composition were not significantly altered following the 4-week exercise intervention. However, there was a significant group×time interaction for TNF-α. The post hoc test revealed that the level of TNF-α significantly decreased only in EX (EX: mean±standard deviation, Pre 55.18±6.57 pg/mL, Post 50.31±6.22, P=0.018 vs. CON: Pre 55.5±5.88, Post 58.19±6.48, P=0.25). EX Post was also significantly lower as compared to CON Post (P=0.0074). Although there was no change in body weight or fat mass, the 4-week aerobic exercise training was long enough to decrease the level of TNF-α, indicating physical activity may improve level of inflammation independently from the change in fat mass. The current study also confirmed previous research suggesting that longer period of exercise training accompanied by weight loss may be required to induce significant changes in CRP and adiponectin.

Matrix metalloproteinases in exercise and obesity.

Matrix metalloproteinases (MMPs) are zinc- and calcium-dependent endoproteinases that have the ability to break down extracellular matrix. The large range of MMPs' functions widens their spectrum of potential role as activators or inhibitors in tissue remodeling, cardiovascular diseases, and obesity. In particular, MMP-1, -2, and -9 may be associated with exercise and obesity. Thus, the current study reviewed the effects of different types of exercise (resistance and aerobic) on MMP-1, -2, and -9. Previous studies report that the response of MMP-2 and -9 to resistance exercise is dependent upon the length of exercise training, since long-term resistance exercise training increased both MMP-2 and -9, whereas acute bout of resistance exercise decreased these MMPs. Aerobic exercise produces an inconsistent result on MMPs, although some studies showed a decrease in MMP-1. Obesity is related to a relatively lower level of MMP-9, indicating that an exercise-induced increase in MMP-9 may positively influence obesity. A comprehensive understanding of the relationship between exercise, obesity, and MMPs does not exist yet. Future studies examining the acute and chronic responses of these MMPs using different subject models may provide a better understanding of the molecular mechanisms that are associated with exercise, obesity, and cardiovascular disease.

Niacin increased glucose, insulin, and C-peptide levels in sedentary nondiabetic postmenopausal women.

The current study examined the effects of niacin and a single bout of aerobic exercise on plasma glucose, insulin, and C-peptide in sedentary, nondiabetic postmenopausal women. As a crossover design, 17 participants underwent four different trials: rest during the no-niacin condition (R), exercise during the no-niacin condition (E), rest during the with-niacin condition (RN), and exercise during the with-niacin condition (EN). All participants took 1,000 mg/day of extended-release niacin for 4 weeks during the with-niacin conditions (RN and EN). The exercise treatment consisted of a single bout of treadmill walking at 60% heart rate reserve until 400 kcal were expended. Blood samples were collected at 24 hours after each trial and analyzed for changes in plasma glucose, insulin, and C-peptide. A two by two analysis of variance was used to examine the changes in dependent variables, and the Bonferroni adjustment was employed as the post hoc test. The level of statistical significance was set at P<0.05. There was no significant interaction between exercise and niacin, nor was there a main effect of exercise for changes in glucose, insulin, or C-peptide. However, there was a significant main effect for niacin as mean glucose, insulin, and C-peptide values significantly increased with niacin; glucose increased 10.6% (P=0.001), from 95.03±10.67 mg/dL to 105.07±13.56 mg/dL; insulin increased 61.8% (P=0.001), from 16.98±12.49 µU/mL to 27.48±14.84 µU/mL; and C-peptide increased 46.1% (P=0.001), from 1.65±0.75 ng/mL to 2.41±0.97 ng/mL. Although niacin was generally well tolerated, given its adverse effects on glucose, insulin, and C-peptide profiles, the use of niacin should be done so with caution and under medical supervision.

Responses of blood lipids and lipoproteins to extended-release niacin and exercise in sedentary postmenopausal women.

Niacin and exercise positively alter blood lipids and lipoproteins via different mechanisms. However, the effects of niacin combined with exercise on blood lipid and lipoprotein profiles have not been investigated in sedentary postmenopausal women. The current study examined the responses of blood lipids and lipoproteins to niacin and exercise in 18 sedentary postmenopausal women, who underwent four conditions: no-niacin rest, no-niacin exercise, niacin rest, and niacin exercise. Participants ingested 1,000 mg/day of extended-release niacin for 4 weeks during the niacin condition. As an exercise treatment, participants performed a single bout of exercise on a treadmill at 60% heart rate reserve until 400 kcal were expended. Extended-release niacin without the exercise intervention significantly (p < .001) increased high-density lipoprotein cholesterol and high-density lipoprotein-2 cholesterol by 12.4% and 33.3%, respectively, and decreased the total cholesterol to high-density lipoprotein cholesterol ratio by 14.8%. Thus, 4 weeks of 1,000 mg/day of extended-release niacin can improve the blood lipid and lipoprotein profiles in sedentary postmenopausal women.