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This study investigated the effects of 6 mg/day of astaxanthin supplementation on markers of oxidative stress and substrate metabolism during a graded exercise test in active young men. A double-blind, randomized, counterbalanced, cross-over design was used. Fourteen men (age = 23 ± 2 years) supplemented with 6 mg/day of astaxanthin and a placebo for 4 weeks, with a 1 week washout period between treatments. Following each supplementation period, a fasting blood sample was obtained to measure markers of oxidative stress: glutathione, hydrogen peroxide, advanced oxidation protein products, and malondialdehyde. Participants also completed a graded exercise test after each treatment to determine substrate utilization during exercise at increasing levels of intensity. Glutathione was ∼7% higher following astaxanthin compared with placebo (1,233 ± 133 vs. 1,156 ± 185 μM, respectively; p = .02, d = 0.48). Plasma hydrogen peroxide and malondialdehyde were not different between treatments (p > .05). Although not statistically significant (p = .45), advanced oxidation protein products were reduced by ∼28%. During the graded exercise test, mean fat oxidation rates were not different between treatments (p > .05); however, fat oxidation decreased from 50 to 120 W (p p = .004) in both conditions. Astaxanthin supplementation of 6 mg/day for 4 weeks increased whole blood levels of the antioxidant glutathione in active young men but did not affect oxidative stress markers or substrate utilization during exercise. Astaxanthin appears to be an effective agent to increase endogenous antioxidant status.

Although whole food nutrition will likely influence physical health more than any other lifestyle component besides exercise, the use of dietary supplements among men and women continues to be high. Due to this fact, it is imperative that healthcare professionals understand how supplements may impact overall health and wellness of their patients. With the majority of adults taking some form of dietary supplements and many concomitantly taking prescription medications, healthcare providers should be conscientious of adverse effects and interactions that may occur between dietary supplements and prescription drugs. As many consumers are misled by false marketing, healthcare providers should encourage them to be wary of exaggerated claims and direct them to products that are scientifically supported and safe. Continuing education for healthcare providers on dietary supplements is crucial, with new dietary supplement products constantly reaching the markets, in addition to new findings being made through clinical research and case studies. While some dietary supplements provide no meaningful benefit, many dietary supplements have been identified that can be used to ameliorate nutritional deficiencies and reduce the risk of some common health conditions. Others can serve to improve mental and physical performance, while truly enhancing health. This article presents relevant information on dietary supplements that will be useful to the healthcare professional.

Firefighters and military personnel are exposed to a variety of stressors. The combination of mental and physical stress (i.e., dual stress challenges [DSCs]) results in significant oxidative stress (OS), which may contribute to cardiometabolic dysfunction. Curcumin (CUR) is an exogenous antioxidant that may attenuate such OS. Fourteen trained men participated in a randomized, cross-over design to investigate the impact of CUR on markers of OS resulting from DSC. CUR or placebo was ingested three days prior to, and the morning of, testing. The DSC involved 20 min of mental stress challenges during 35 min of cycling at 60% V̇O

Time-restricted feeding (TRF) is becoming a popular way of eating in physically active populations, despite a lack of research on metabolic and performance outcomes as they relate to the timing of food consumption in relation to the time of exercise. The purpose of this study was to determine if the timing of feeding/fasting after exercise training differently affects muscle metabolic flexibility and response to an acute bout of exercise. Male C57BL/6 mice were randomized to one of three groups for 8 weeks. The control had ad libitum access to food before and after exercise training. TRF-immediate had immediate access to food for 6 h following exercise training and the TRF-delayed group had access to food 5-h post exercise for 6 h. The timing of fasting did not impact performance in a run to fatigue despite TRF groups having lower hindlimb muscle mass. TRF-delayed had lower levels of muscle HSL mRNA expression and lower levels of PGC-1α expression but displayed no changes in electron transport chain enzymes. These results suggest that in young populations consuming a healthy diet and exercising, the timing of fasting may not substantially impact metabolic flexibility and running performance.

Mounting evidence suggests diet and exercise influence learning and memory (LM). We compared a high-fat, high-sucrose Western diet (WD) to a plant-based, amylose/amylopectin blend, lower-fat diet known as the Daniel Fast (DF) in rats with and without regular aerobic exercise on a task of spatial working memory (WM).Rats were randomly assigned to the WD or DF at 6 weeks of age. Exercised rats (WD-E, DF-E) ran on a treadmill 3 times/week for 30 min while the sedentary rats did not (WD-S, DF-S). Rats adhered to these assignments for 12 weeks, inclusive ofDF-E rats exhibited the best DSA performance. Surprisingly, the WD-S group outperformed the WD-E group, but had significantly lower BDNF and ARC relative to the DF-S group, with a similar trend from the WD-E group. P-STAT3 expression was also significantly elevated in the WD-S group compared to both the DF-S and WD-E groups.These results support previous research demonstrating negative effects of the WD on spatial LM, demonstrate the plant-based DF regimen combined with chronic aerobic exercise produces measurable WM and neuroprotective benefits, and suggest the need to carefully design exercise prescriptions to avoid over-stressing individuals making concurrent dietary changes.

Background: Improvements in body composition have been reported when men and women switch from consuming a Western Diet (WD) to a purified and “clean” diet (PD) known as a "Daniel Fast.” While no laboratory studies have determined physical performance improvements following the Daniel Fast, numerous anecdotal reports of improved physical capacity and well-being have been noted. Methods: In the present study, Long-Evans rats (N=28) were assigned to be exercise trained (+E) by running on a treadmill three days per week or to act as sedentary controls. After baseline physical performance was evaluated by recording run time to exhaustion, half of the animals in each group were fed for 12 months either a PD formulated to mimic the Daniel Fast, or a WD. Food was provided ad libitum during months 1-3 and was restricted to 90% of animals’ daily needs during months 4-12. Physical performance was evaluated again at the end of months 3, 6, 9, and 12, as was body composition and bone mineral density using dual energy x-ray absorptiometry. Results: As expected, exercise resulted in an increase in run time as compared to the non-exercise control animals (p

Waldman, HS, Smith, JW, Lamberth, J, Fountain, BJ, Bloomer, RJ, Butawan, MB, and McAllister, MJ. A 28-day carbohydrate-restricted diet improves markers of cardiovascular disease in professional firefighters. J Strength Cond Res 34(10): 2785-2792, 2020-This study compared the effects of a 4-week, nonketogenic, carbohydrate-restricted (

OBJECTIVES: Food intake and exercise are considered modulators of the immune system. Specifically, intermittent fasting protocols have been demonstrated to reduce inflammation and alter cytokine responses. The objective of the current study was to determine if a form of intermittent fasting known as time-restricted feeding (TRF) would alter immune parameters in response to exercise. METHODS: 8-week-old C57BL/6 male mice were divided into three groups based on feeding schedule; group one had access to food ad libitum (Control) and groups two and three had access to food in a time restricted manner. Access was allowed for six hours per day either immediately after running (TRF-imm) or six hours after running (TRF-del). Mice ran on a treadmill for 1 hour, 5 days per week for eight weeks. Diet consisted of 21% protein, 16% fat and 64% carbohydrate. Weight, glucose and ketone levels, and immune populations were analyzed. Systemic IL-6 and TNF-α levels were measured before and after running. In a subpopulation, cytokine response to lipopolysaccharides (LPS) was also monitored. RESULTS: All mice gained weight during the eight-week intervention, but TRF-imm gained significantly less weight than Control (P = 0.02). No differences were detected in glucose levels. The ketone body β-hydroxybutyrate (BHB) was significantly higher at week eight in TRF groups (P ≤ 0.03) but running induced BHB in all groups to approximately 1 mM. Running reduced the blood lymphocytes levels (P

Background: Certain dietary fibers have been reported to improve gut health and cellular immunity. Ambrotose is a glyconutrient supplement that contains mannose-rich polysaccharides (acemannan), reported to improve immune function. A more nutrient-dense version of this dietary supplement has been developed recently, with added aloe leaf gel powder (acemannan). The purpose of this study was to evaluate the impact of the traditional and newly developed Ambrotose products on immunity, gut health, and psychological well-being in healthy men and women. Methods: Seventy-five men and women were randomly assigned in double-blind manner to one of five treatments, as follows: Ambrotose Advanced (AA) at 2 or 4 g daily, Ambrotose LIFE (AL) at 2 or 4 g daily, or placebo. Subjects ingested their assigned treatment daily for eight weeks. Resting heart rate, blood pressure, and measures of psychological well-being were analyzed before and after four and eight weeks of supplementation. Blood samples were collected at the same times and analyzed for zonulin, hematology measures, and cytokines&mdash, IL-6, IL-10, IL-1&beta, and TNF-&alpha, (analyzed both with and without stimulation via lipopolysaccharide [LPS]). Results: All Ambrotose treatments were well-tolerated. There were no differences among treatments in heart rate or blood pressure across time. Self-reported well-being scores were generally higher for the Ambrotose treatments but there were no changes of statistical significance across time (p &gt, 0.05). Differences of statistical significance were noted for select biochemical variables, the most notable being a dramatic decrease in monocytes in the Ambrotose groups. No change was noted in the cytokine response to LPS stimulation in all groups, indicating a maintenance of a healthy immune response. Conclusion: Regular supplementation with Ambrotose is safe and can improve subclinical cellular adversity (as evidenced by a decrease in monocytes), without unnecessary activation of an immune response.

Background: Dietary supplements purported to improve focus and “energy” often contain stimulants, which elevate both heart rate (HR) and blood pressure (BP). We evaluated the safety profile of the purine alkaloid methylliberine (Dynamine®) with regards to resting HR, BP, respiratory rate (RR), and body temperature (BT). Methods: 6 men (aged: 24±4) and 6 women (aged: 22±3) ingested methylliberine (Dynamine®; Compound Solutions, Inc.) at 25mg (M25) and 100mg (M100), caffeine at 150mg (C150), M100+C150, M100 + theacrine (Teacrine®, Compound Solutions, Inc.) at 50mg (M100+T50), and M100+T50+C150. All conditions were assigned using a Latin square design, with approximately one week separating the six different assignments. HR, BP, RR, and BT were collected at baseline and 0.25, 0.5, 1, 1.5, 2, 4, 6, 8, 24, and 48 hours post-dose. Subjective mood was also recorded. Meal replacement bars and shakes were provided after hours 3 and 6. Results: For SBP and DBP, condition effects were noted (p

Methylsulfonylmethane (MSM) is a naturally occurring organosulfur antioxidant. Based on its small size and unique physicochemical properties, MSM exhibits broad tissue distribution and pleiotropic effects. Animal toxicity studies suggest MSM is safe and nontoxic. Though the antioxidant mechanism is presently unclear, MSM has demonstrated the ability to protect against the activities of superoxide dismutase, catalase, and myeloperoxidase while also altering glutathione levels in numerous tissues. Through the modulation of antioxidant enzyme activities and redox hub cycling, MSM impacts cellular and tissue redox status, which can metabolically reprogram cells through redox-sensitive transcription factors. Alternatively, MSM may also affect membrane properties, specifically of mitochondria, thereby affecting reactive oxygen species production. By altering antioxidant potentials in various tissues including the brain, MSM may demonstrate unique immune modulatory properties that could prove useful to various pathological states.

Objective Firefighters (FFs) involved in fire suppression have the greatest on-duty risk of cardiovascular disease (CVD), which may be caused by oxidative stress (OS). Methods Healthy, active FFs performed a victim "search and clear" exercise involving three conditions: (1) no heat, (2) heat + antioxidant, and (3) heat + placebo. Blood samples were analyzed for OS markers glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), and advanced oxidation protein products (AOPP). Results Increased GSH was found during both heat conditions compared with no heat. CAT activity was higher immediately post exercise. AOPP was reduced post exercise. Conclusions Antioxidant supplementation did not impact the OS response to exercise. Added heat did not cause OS and exercise resulted in reductions in OS markers. These findings can be attributed to the training status of the FFs involved.

Background: The use of standing desks has been associated with greater metabolic cost as compared to traditional seated desks. However, it is unclear as to the metabolic impact of standing desks in normal weight versus obese men and women. Methods: We compared the metabolic cost of using a standing and seated desk in 14 obese and 19 normal weight men and women. Subjects reported to the lab on a single occasion and participated in two, 30-minute sessions of standing and seated desk work (i.e., typing), in random order. Expired gases were collected during the 2-hour period and calorie expenditure was estimated using indirect calorimetry. Results: We noted a significant (p = 0.013) increase in energy expenditure of 7.4 kcal•30 minutes−1 (+14.7%) during standing as compared to seated for the obese group. No significant difference in energy expenditure was noted for the normal weight group (p = 0.674). A condition effect was noted for heart rate and diastolic blood pressure, with standing being significantly higher than seated for both variables (p 0.05). Conclusion: The use of a standing desk modestly increases energy expenditure in obese subjects but does not have the same effect in those of normal weight. It is unknown whether the increased energy expenditure would be maintained over time in the obese subjects/individuals, as they may adapt to the standing position. Moreover, if normal weight individuals choose a standing desk, they should do so for reasons unrelated to increased energy expenditure (e.g., improved spine health, greater feeling of productivity).

Background: The smoking of Cannabis sativa, the marijuana plant, is increasing in popularity among young adults, even those who may be engaged in regular exercise (i.e., athletes). Research has shown the plant to have antioxidant and analgesic properties, but the effects on oxidative stress are conflicting. The purpose of this study was to measure blood oxidative stress and cardio-metabolic parameters in physically active men and women who regularly smoke marijuana. Methods: A total of 43 marijuana smokers (23 ± 4 years) and 22 non-smokers (24 ± 7 years), who did not smoke tobacco products, participated in this study. Both smokers and non-smokers engaged in regularly exercise, totaling several hours per week (6.4 ± 4.0 and 6.8 ± 4.4, respectively). Smokers reported using marijuana frequently during the week (4.5 ± 2.3 sessions) for a minimum of three consecutive months prior to participating in the study. Blood samples were collected from participants following a 12-hour fast (all food, drink [except water] and smoking) and analyzed for malondialdehyde, advanced oxidation protein products, glucose, cholesterol, and triglycerides. Heart rate and blood pressure was also measured and recorded. Results: No differences of statistical significance were noted for any variable (p > 0.05), with very similar values noted between smokers and non-smokers. Conclusions: In a sample of young, physically active men and women, regular marijuana smoking is not associated with untoward effects on select biomarkers of oxidative stress and cardio-metabolic health. These findings do not suggest that marijuana smoking can be done without harm, as limitations of this study need to be considered.

Poor dietary habits can lead to obesity and insulin resistance—both of which can impair basal heat shock protein (HSP) expression and the HSP stress response in skeletal muscle. It remains unclear if impairments in HSP expression occur during the early stages of diet-induced obesity and metabolic dysfunction. We determined if basal HSP expression (HSP70, HSP60, HSP25) was impaired in sedentary or exercised rats following the onset of diet-induced obesity. Male Long-Evans rats (N=6-7/group) were assigned to a Western diet (WD) or purified diet (PD). Animals were divided into sedentary (WD and PD) or exercise-trained (WD+Ex and PD+Ex) groups and fed ad libitum for 12-weeks. WD animals displayed higher body mass, fat mass, blood glucose, and HOMA-IR scores compared to PD (p0.05) but did not prevent elevations in fat mass or blood glucose when compared to controls. Basal HSP (HSP70, HSP60, HSP25) expression was not impaired in sedentary WD animals when compared to PD (p>0.05) or when WD+Ex was compared to PD+Ex (p>0.05). Exercise training elevated HSP70 expression in the gastrocnemius muscle (GAST) (p0.05) in WD+Ex and PD+Ex animals. HSP60 and pHSP25 were unaffected by exercise training (GAST and SOL, p>0.05). The onset of diet-induced obesity does not impair skeletal muscle HSP expression in sedentary or exercised animals. Thus, obesity and symptomology of metabolic dysfunction may occur before reductions in skeletal muscle HSP expression.

Background: We have previously reported improvements in selected biochemical measures of health, as well as self reported well-being in men and women using the dietary supplement known as CLOCK®. In this follow up investigation, we evaluated CLOCK® at two different dosages using a randomized, placebo controlled, cross-over design in men and women with self reported low energy, impaired sleep quality and impaired well-being. Methods: 30 subjects (14 men and 16 women) were randomly assigned in double blind manner to ingest a botanical agent (CLOCK®, containing Rosmarinus officinalis and Hemerocallis fulva at either 1gram or 1.5grams daily) or a placebo for two week periods with a two week wash out period after each condition assignment. Blood samples were collected pre and post each two week period in an overnight fasted state and Analyzed for acetylcholine (ACh), choline, Brain Derived Neurotrophic Factor (BDNF), IGF-1, irisin, melatonin and serotonin. Heart rate and blood pressure were measured, as were subjective measures of well-being. The Leeds Sleep Evaluation Questionnaire was used as a measure of sleep quality and related variables. Results: ACh (22%), choline (19%), BDNF (44%), irisin (23%) and melatonin (8%) all increased significantly from pre to post intervention following intake of CLOCK® (with a greater increase noted with 1gram vs. 1.5grams) but not placebo. Heart rate and blood pressure were unaffected by treatment (p>0.05). Time effects were noted for all well-being measures (p0.05). Conclusion: CLOCK® significantly impacts biochemical variables related to health, while having little impact on resting heart rate or blood pressure.

Runners often experience delayed onset muscle soreness (DOMS), especially of the knee extensors, following prolonged running. Sagittal knee joint biomechanics are altered in the presence of knee extensor DOMS but it is unclear how muscle soreness affects lower limb biomechanics in other planes of motion. The purpose of this study was to assess the effects of knee extensor DOMS on three-dimensional (3D) lower limb biomechanics during running. Thirty-three healthy men (25.8 ± 6.8 years; 84.1 ± 9.2 kg; 1.77 ± 0.07 m) completed an isolated eccentric knee extensor damaging protocol to elicit DOMS. Biomechanics of over-ground running at a set speed of 3.35 m s−1±5% were measured before eccentric exercise (baseline) and, 24 h and 48 h following exercise in the presence of knee extensor DOMS. Knee flexion ROM was reduced at 48 h (P = 0.01; d = 0.26), and peak knee extensor moment was reduced at 24 h (P = 0.001; d = 0.49) and 48 h (P

Research has focused on the effects of acute strike pattern modifications on lower extremity joint stiffness and running economy (RE). Strike pattern modifications on running biomechanics have mostly been studied while runners complete short running bouts. This study examined the effects of an imposed forefoot strike (FFS) on RE and ankle and knee joint stiffness before and after a long run in habitual rearfoot strike (RFS) runners. Joint kinetics and RE were collected before and after a long run. Sagittal joint kinetics were computed from kinematic and ground reaction force data that were collected during over-ground running trials in 13 male runners. RE was measured during treadmill running. Knee flexion range of motion, knee extensor moment and ankle joint stiffness were lower while plantarflexor moment and knee joint stiffness were greater during imposed FFS compared with RFS. The long run did not influence the difference in ankle and knee joint stiffness between strike patterns. Runners were more economical during RFS than imposed FFS and RE was not influenced by the long run. These findings suggest that using a FFS pattern towards the end of a long run may not be mechanically or metabolically beneficial for well-trained male RFS runners.

Ingestion of ketone supplements, caffeine, and medium-chain triglycerides (MCTs) may all be effective strategies to increase blood levels of the ketone body beta-hydroxybutyrate (D-BHB). However, acute ingestion of a bolus of lipids may increase oxidative stress (OS). The purpose of the study was to investigate the impact of adding varying amounts of MCTs to coffee on blood levels of D-BHB and markers of OS. Ten college-aged men ingested coffee with 0, 28, and 42 g of MCT in a randomized order. Blood samples were collected pre- as well as 2 and 4 h postprandial and analyzed for D-BHB, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), glucose, triglycerides (TAG), insulin, and OS markers: advanced oxidation protein products (AOPP), glutathione (GSH), malondialdehyde (MDA), and hydrogen peroxide (H2O2). All three treatments resulted in a significant increase in D-BHB, HDL-c, and TC as well as a significant decrease in TAG, MDA, H2O2, and insulin. The 42 g treatment was associated with significantly higher levels of AOPP and MDA. Acute ingestion of coffee results in favorable changes to markers of cardiometabolic health that were not impacted by the addition of 28 g of MCT. However, 42 g of MCT caused significantly greater OS.

Methylsulfonylmethane (MSM) is a naturally occurring organosulfur compound that has gained popularity as a dietary supplement and is used for a variety of purposes, including as an antiinflammatory agent. Multiple in vitro, animal, and human studies support its use as a safe and effective agent in the treatment of inflammatory conditions, including arthritis. As a GRAS substance, MSM is well tolerated at oral dosages of 2–4 g daily, with few observed side effects. This chapter provides an overview of MSM, with specific attention paid to the role of this dietary supplement in the treatment of inflammatory conditions.

Carnitine is a natural component of mammalian tissue and is involved in multiple physiological roles. In relation to physical exercise, these include, but are not limited to, providing antioxidant protection, increasing nitric oxide production and/or maintaining circulating nitric oxide, and working to enhance energy production (e.g., fatty acid oxidation). These outcomes may be directly or indirectly related to improved exercise performance or recovery from strenuous exercise. Some studies have noted favorable outcomes with regard to exercise performance or related measures following carnitine supplementation, whereas others have failed to demonstrate an ergogenic effect, in particular when carnitine is used by healthy, exercise-trained individuals. The type and dosage of carnitine used vary considerably across studies, and few direct comparisons have been made between carnitine forms. This chapter provides a brief overview of the work in the area of carnitine supplementation.

Aim: Phytochemicals from fruits and vegetables are known to reduce inflammation and improve overall health. The objective of this study was to determine the effect of a fruit and vegetable concentrate (FVC) and high fiber component on the gut microbiome in an overweight/obese, female population. Methods: The study was a randomized, double blind, placebo-controlled trial with 57 asymptomatic, pre-menopausal, overweight/obese females between 25–50 years of age working in healthcare. Blood and fecal samples were collected before and after two, four and five months of daily supplementation. Metabolic parameters were measured, and the gut microbiome analyzed. Results: No effect was observed with FVC supplementation for blood lipids, glucose and immune parameters. There was an improvement in glucose clearance. The FVC supplement did not result in taxonomic alterations at phyla level, or changes in α or β diversity, but reduced Bacteroides abundance and increased fecal butyrate. An additional high fiber component improved levels of health associated bacteria. Conclusion: The results suggest that a dried fruit and vegetable supplement, with a high fiber meal replacement can alter the intestinal microbiota and improve glucose clearance, suggesting that this combination of supplements can improve glucose metabolism and possibly reduce the risk of insulin resistance.

Jirakrit Leelarungrayub,1 Araya Yankai,1 Decha Pinkaew,1 Rungthip Puntumetakul,2 James J Laskin,3 Richard J Bloomer4 1Department of Physical Therapy, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 2Research Center in Back, Neck, Other Joint Pain and Human Performance (BNOJPH), Khon Kaen University, Khon Kaen, Thailand; 3School of Physical Therapy and Rehabilitation Sciences, University of Montana, Missoula, MT, 4Cardiorespiratory/Metabolic Laboratory, School of Health Studies, University of Memphis, Memphis, TN, USA Objective: The aims of this preliminary study were to evaluate the antioxidant and lipid status before and after star fruit juice consumption in healthy elderly subjects, and the vitamins in star fruit extracts.Methods: A preliminary designated protocol was performed in 27 elderly individuals with a mean (±SD) age of 69.5±5.3 years, by planning a 2-week control period before 4 weeks of consumption of star fruit twice daily. Oxidative stress parameters such as total antioxidant capacity, glutathione, malondialdehyde, protein hydroperoxide, multivitamins such as L-ascorbic acid (Vit C), retinoic acid (Vit A), and tocopherol (Vit E), and the lipid profile parameters such as cholesterol, triglyceride, high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C) were analyzed. Moreover, Vit C, Vit A, and Vit E levels were evaluated in the star fruit extracts during the 4-week period.Results: In the 2-week control period, all parameters showed no statistically significant difference; after 4 weeks of consumption, significant improvement in the antioxidant status was observed with increased total antioxidant capacity and reduced malondialdehyde and protein hydroperoxide levels, as well as significantly increased levels of Vit C and Vit A, when compared to the two-time evaluation during the baseline periods. However, glutathione and Vit E showed no statistical difference. In addition, the HDL-C level was higher and the LDL-C level was significantly lower when compared to both baseline periods. But the levels of triglyceride and cholesterol showed no difference. Vit C and Vit A were identified in small quantities in the star fruit extract.Conclusion: This preliminary study suggested that consumption of star fruit juice twice daily for 1 month improved the elderly people’s antioxidant status and vitamins, as well as improved the lipoproteins related to Vit C and Vit A in the star fruit extract. Keywords: star fruit, elderly, antioxidants, vitamins, lipid, oxidative stress

Purpose This study aimed to evaluate the effect of star fruit juice supplementation on tumor necrosis factor-alpha (TNF-α), interleukin-23 (IL-23) and interleukin-2 (IL-2), nitric oxide (NO), and 6 min walking distance (6MWD) in a group of elderly individuals. Methods Twenty-nine individuals (20 males, 9 females) with a mean age of 72.4 ± 8.3 years completed this study. A two-week control period was followed by four weeks of 100 g fresh star fruit juice consumption twice per day after meals. Results Plasma TNF-α, IL-23, IL-2, NO and the 6MWD were evaluated twice during the control period (weeks 0 and 2) and once after the star fruit juice consumption (week 6). Results The results showed that all parameters in the blood did not change significantly during the control period. After 4 weeks of star fruit juice consumption, a significant reduction in NO, TNF-α and IL-23 was found; however, there was no change in IL-2. Moreover, the 6MWD increased significantly at week 6, when compared to that at week 0 and 2. Furthermore, the results also showed a significantly positive and negative correlation of NO and TNF-α to the 6MWD, but no correlation of IL-23 and IL-2. Conclusion This preliminary study concluded that consumption of star fruit juice at 100 g twice daily for one month can significantly depress the pro-inflammation cytokines: TNF-α, IL-23, and NO, while increasing walking distance. Low TNF-α and high NO also present a significant correlation to walking capacity in elderly individuals.

Plant-based nutrients have been studied for their potential impact on testosterone production in men. We investigated the influence of a novel passion flower extract on free testosterone in healthy men. In part one of this study, 18 younger men (35.9 ± 1.6 years) were assigned to consume placebo tablets or tablets containing a passion flower extract, in a random order, double-blind, cross-over design. The treatment period for each condition was 15 days, with a two-week washout period between conditions. Blood and saliva were collected both in the morning and the evening on days 1, 8, and 15—both before and one hour following ingestion of the assigned condition. In part two of this study, seven older men (55.9 ± 2.7 years) were assigned to consume the passion flower extract or placebo tablets in a random order, double-blind, cross-over design. The treatment period was the same as for part one and but only saliva was collected in the morning on days 1, 3, 8, and 15. All subjects completed a questionnaire on the morning of each test day to determine their subjective feelings associated with the condition treatment. Passion flower extract did not appear to influence free testosterone or subjective feelings in younger men. However, free salivary testosterone was increased an average of 13% in older men. In addition, an increase of 17% was noted from day 1 to day 15 for perceived energy level, while an increase of 9% was noted for libido when older men used the extract. A novel passion flower extract does not influence testosterone concentrations or subjective feelings in younger men but may have an influence on these outcomes in selected older men. It is possible that the treatment may be more effective when delivered to those with low baseline testosterone values.

Background: We investigated the influence of a botanical agent to improve sleep quality and associated measures in men and women with self-reported difficulty sleeping. Methods: 32 individuals were randomly assigned in double blind manner to ingest a botanical agent (CLOCK?, containing Rosemary [Rosmarinus officinalis] and Daylily [Hemerocallis fulva]) or a placebo over a 6-week intervention. During weeks 1 and 2, subjects ingested one serving of the assigned condition, followed by a two-week washout. During weeks 5 and 6, subjects ingested two servings of the condition. The Leeds Sleep Evaluation Questionnaire was used as an outcome measure, as were subjective measures of sleep quality, energy level, and mood. Blood samples collected pre- and post-intervention were assayed for acetylcholine (ACH), brain-derived neurotrophic factor (BDNF), irisin, and melatonin. Results: No differences were noted between conditions in measures of sleep (p > 0.05). While no differences of statistical significance were noted in subjective feelings, during weeks 5 and 6 as compared to baseline, subjects assigned to the supplement noted an 8% increase in attentiveness, an 11% increase in alertness, a 12% increase in focus, a 14% increase in feeling energetic, a 12% increase in enthusiasm, a 23% increase in feeling well rested, an 11% decrease in feeling sluggish, and a 16% decrease in feeling depressed, without the same improvement observed for subjects in the placebo group. All biochemical measures were increased from pre- to post-treatment with two servings of the supplement; the largest percent increase noted for BDNF (27%) and the largest effect size noted for irisin (d = 1.36). Biochemical values for the placebo condition were unchanged. Conclusions: CLOCK? may have an impact on certain measurements of mood, with a significant impact on the biochemical marker, BDNF. Future studies using a larger sample size and perhaps a cross-over design may help to further clarify the impact of this dietary supplement on aspects of sleep quality, mood, and other related variables.

Background Fasting and timed feeding strategies normalize obesity parameters even under high-fat dietary intake. Although previous work demonstrated that these dietary strategies reduce adiposity and improve metabolic health, limited work has examined intestinal microbial communities. Objectives We determined whether timed feeding modifies the composition of the intestinal microbiome and mycobiome (yeast and fungi). Methods Male C57BL/6 mice were fed a high-fat diet (HF) for 6 wk. Animals were then randomly assigned to the following groups (n = 8–10/group): 1) HF ad libitum; 2) purified high-fiber diet (Daniel Fast, DF); 3) HF–time-restricted feeding (TRF) (6 h); 4) HF–alternate-day fasting (ADF); or 5) HF at 80% total caloric restriction (CR). After 8 wk, obesity and gut parameters were characterized. We also examined changes to the gut microbiome and mycobiome before, during, and following dietary interventions. Results Body mass gain was reduced with all restricted dietary groups. HF-fed microbiota displayed lower α-diversity along with reduced phylum levels of Bacteroidetes and increased Firmicutes. Animals switched from HF to DF demonstrated a rapid transition in bacterial taxonomic composition, α-, and β-diversity that initially resembled HF, but was distinct after 4 and 8 wk of DF feeding. Time-or calorie-restricted HF-fed groups did not show changes at the phylum level, but α-diversity was increased, with specific genera altered. Six weeks of HF feeding reduced various fungal populations, particularly Alternaria, Aspergillus, Cladosporium, and Talaromyces, and increased Candida, Hanseniaspora, and Kurtzmaniella. However, 8 wk of intervention did not change the fungal populations, with the most abundant genera being Candida, Penicillium, and Hanseniaspora. Conclusions These data suggest that timed-feeding protocols and diet composition do not significantly affect the gut fungal community, despite inducing measurable shifts in the bacterial population that coincide with improvements in metabolism.

Purpose Those engaged in high stress occupations such as firefighters and military personnel are exposed to a variety of psychological and physiological stressors. The combination of mental and physical stress [i.e., dual stress challenges (DSC)] results in significant increases in stress hormones, which causes oxidative stress (OS) and contributes to elevated risk for cardiovascular disease. However, data are needed to determine the impact of DSC on markers of OS in exercise-trained individuals. Method Fourteen healthy trained men aged 21–30 yrs. participated in a randomized, cross-over design to investigate the impact of DSC on blood markers of OS. The exercise alone condition (EA) consisted of 35 min of cycling at 60% VO2 peak. The DSC involved 20 min of mental stress challenges during exercise. Blood was sampled before exercise, as well as immediately, and 30 and 60 min after exercise and analyzed for glutathione (GSH), superoxide dismutase (SOD), hydrogen peroxide (H2O2) and advanced oxidation protein products (AOPP). Result No significant treatment × time interactions were found. No time effects were noted for SOD, or H2O2; however, AOPP were reduced at 30 (p = .034) and 60 min post exercise (p = .006). GSH was reduced at 30 (p = .009) and 60 min post exercise (p = .031). Conclusion These results indicate the OS response from DSC is not greater than that produced from EA in exercise trained men. Future work should investigate the impact of chronic resistance and endurance exercise training on OS resulting from DSC.

Time-restricted feeding (TRF) limits the duration of food availability without altering diet composition and can combat obesity in humans and mice. For this study we evaluated the effect of timing of food access during a TRF protocol on weight gain, adiposity, and inflammation. Young male C57BL/6 mice were placed on a high-fat (HF) diet (45% fat) for 8 weeks. Food access was unrestricted (HF) or restricted to 6 h per day, either for the first half (HF-early) or the second half (HF-late) of the active phase to resemble a window of time for food consumption early or late in the day in a human population. Weight, obesity-associated parameters, and inflammation were measured. TRF reduced weight gain over the 8-week period in mice consuming the same high-fat diet. Consistent with decreased weight gain in the TRF groups, body fat percentage, liver triglycerides, and plasma leptin and cholesterol levels were reduced. Adipose tissue inflammation, measured by CD11b+F4/80+ macrophage infiltration, was reduced in both TRF groups, but systemic tumor necrosis factor-α was increased in all groups consuming the high-fat diet. The HF-late group gained more weight than the HF-early group and had increased insulin resistance, while the HF-early group was protected. Therefore, a TRF protocol is beneficial for weight management when a high-fat diet is consumed, with food consumption earlier in the day showing greater health benefits. However, increased inflammatory markers in the TRF groups suggest that diet components can still increase inflammation even in the absence of overt obesity.

Objective: slightly elevated have been independently reported to favorably impact blood glucose. To our knowledge, no study has combined these two ingredients through oral supplementation in an attempt to modify the glycemic response to a glucose load. We determined the impact of acute ingestion of a novel glycine-cinnamon extract mixture on blood glucose, insulin, and related variables following an oral glucose challenge.Methods: Ten men and women (25.4 ± 8.3 yrs) with elevated fasting blood glucose (101.2 ± 6.6 mg•dL-1) ingested a 25 gram glucose beverage with and without SugarClear™, a proprietary blend of glycine+cinnamon extract (as Cinnulin PF®), separated by approximately one week. Blood was collected before and at 20, 60, and 120 minutes post ingestion and analyzed for glucose, insulin, glucagon-like peptide-1 (GLP-1), glucagon, ATP, and brainderived neurotrophic factor (BDNF).Results: Significant reductions in the area under the curve (AUC) were noted for both glucose (15% for total AUC and 52% for net incremental AUC) and insulin (7% for total AUC and 57% for net incremental AUC). The total AUC for GLP-1 was increased by 36%, while the AUC for ATP was increased by 20%. Glucagon was lower by 10% and BDNF higher by 5% with treatment but not in a statistically significant manner (p>0.05).Conclusion: Acute ingestion of SugarClear™, a proprietary blend of glycine and cinnamon extract, promotes a positive impact on blood glucose and insulin following an oral glucose load. The mixture also leads to an increase in both the plasma GLP-1 and ATP. These alterations may have favourable metabolic implications in those with elevated blood glucose. Future work is needed to determine the effect of chronic ingestion of SugarClear™ on glucose regulation and related variables.

The principal dietary sources of sulfur, the amino acids methionine and cysteine, may not always be consumed in adequate amounts to meet sulfur requirements. The naturally occurring organosulfur compound, methylsulfonylmethane (MSM), is available as a dietary supplement and has been associated with multiple health benefits. Absorption of MSM by the small intestine and accumulation of the associated sulfur moiety in selected tissues with chronic (8 days) administration were evaluated using juvenile male mice. Intestinal absorption was not saturated at 50 mmol, appeared passive and carrier-independent, with a high capacity (at least 2 g/d-mouse). The 35S associated with MSM did not increase in serum or tissue homogenates between days 2 and 8, indicating a stable equilibrium between intake and elimination was established. In contrast, proteins isolated from the preparations using gel electrophoresis revealed increasing incorporation of 35S in the protein fraction of serum, cellular elements of blood, liver, and small intestine but not skeletal muscle. The potential contributions of protein synthesis using labeled sulfur amino acids synthesized by the gut bacteria and posttranslational sulfation of proteins by incorporation of the labeled sulfate of MSM in 3′-phosphoadenosine 5′-phosphosulfate (PAPS) and subsequent transfer by sulfotransferases are discussed.

D-aspartic acid (DAA), nitrate, and vitamin D3 have received considerable attention in recent years for their potential health-enhancing properties. Using an open-label design, we evaluated the impact of a DAA/sodium nitrate/ vitamin D3 dietary supplement on blood testosterone and nitrate/nitrite, as well as subjective indicators of health, in middle-aged men. Methods: 10 overweight or obese men (mean age: 42 years) were assigned to ingest a DAA/sodium nitrate/ vitamin D3 supplement (either one or two servings per day) for 28 days. Blood total and free testosterone and nitrate/nitrite was measured before and after 14 and 28 days of supplementation. Subjective assessment of to health indicators (e.g., energy level, libido) was included at each collection time. Results: Total and free testosterone increased on average 5-10%, which was not of statistical significance (p>0.05). The response was highly variable; some men failed to respond to treatment, while men with relatively low basal testosterone values experienced increases exceeding 20%. Plasma nitrate/nitrite was increased approximately 6-10 fold after treatment with the supplement, with a trend noted for a time effect (p=0.07). Men reported a significantly better feeling following supplement use, as evidenced by a time effect for both vitality (p=0.02) and libido (p=0.04), with a trend noted for increased energy level (p=0.08) and mental outlook and mood (p=0.10). Conclusion: Twenty-eight days of treatment with a DAA/sodium nitrate/ vitamin D3 dietary supplement increased blood nitrate/nitrite and improved subjective feelings of vitality and libido in middle-aged men. In selected men with low basal testosterone values, the supplement increased circulating levels of this hormone.

Background: The topic of postprandial oxidative stress continues to receive considerable attention, with elevations in oxidative stress biomarkers associated with human disease (e.g., insulin resistance, atherosclerosis). The predictable rise in serum triglyceride (TAG) following high fat meal ingestion is strongly correlated to the increase in circulating oxidative stress biomarkers. Our intent with the present study was two-fold: 1) To further characterize the postprandial response to high fat feeding and 2) to develop regression models that could be used to predict the oxidative stress response to high fat feeding. Methods: 154 men and women reported to the lab in the morning hours following an overnight fast and consumed a high fat liquid meal. Blood samples were collected before meal ingestion and at 2 and 4 hours following meal ingestion. Samples were analyzed for TAG and oxidative stress biomarkers (hydrogen peroxide [H2O2], malondialdehyde [MDA], advanced oxidation protein Original Research Article Bloomer et al; BJMMR, 5(12): 1514-1526, 2015; Article no.BJMMR.2015.171 1515 products [AOPP]). Simple linear regression analyses were used for model development to predict the oxidative stress response to feeding. In addition, biochemical variables were analyzed using an analysis of variance (ANOVA) to present response to feeding data across time. Results: In all of the regression models, TAG explained a significant portion of the outcome variables (H2O2, MDA, and AOPP) and predictor models were created for each variable. In addition, values for TAG and all oxidative stress biomarkers increased following meal ingestion. A time effect was noted where all values were higher post meal ingestion as compared to pre meal for all biochemical variables (p

Background: ELISA procedures are widely available and used for the measurement of saliva and blood (serum and plasma) testosterone. Suggestions for strong correlations between these two fluids have been made but differences in assay format, as well as in the collection procedures, storage, and processing of samples can influence results. Methods: The present study compared saliva and serum free testosterone concentrations in 20 healthy men (31.0±11.0 years; mean ± SD) using ELISA procedures. Men provided both a saliva and blood sample on the same day in the morning hours following an overnight fast. Special care was taken in the collection, storage, and processing of samples. Following complete thawing and mixing of samples, both fluids were analyzed in duplicate using commercially available ELISA kits, both prior to and following centrifugation. Results: Saliva testosterone values were 440.6±238.2 pg ·mL -1 and 348.8±210.0 pg ·mL -1 without and with centrifugation, respectively. Serum testosterone values were 9.0±4.2 pg ·mL -1 and 8.3±3.7 pg ·mL -1 without and with centrifugation, respectively. Conclusion: If utilizing ELISA procedures, saliva and serum testosterone values cannot be used interchangeably, at least when utilizing the ELISA procedures employed in the present study. This is evidenced by the approximate 10-100 times higher testosterone concentration in saliva as compared to serum. Moreover, processing samples via centrifugation leads to a significant (~23%) loss in testosterone in saliva, with a much smaller loss (~7%) in serum. Investigators and Short Research Article

Objective: Theacrine, a methylurate class purine alkaloid, triggers diverse pharmacologic responses, including psychostimulatory activity by modulation of adenosinergic and dopaminergic pathways. In a double-blind, placebo-controlled study, theacrine increased energy, concentration, and mood, while reducing fatigue. Because caffeine, a methylxanthine purine alkaloid, is frequently coadministered with theacrine, we sought to determine if a pharmacokinetic and/or pharmacodynamic interaction existed between theacrine and caffeine. Methods: Eight healthy adults received theacrine, as TeaCrine® (25 or 125 mg), caffeine (150 mg), or a combination of theacrine (125 mg) and caffeine (150 mg) in a randomized, double-blind crossover study. Blood samples were collected over a 24-hour period and analyzed by Liquid chromatrography-mass spectrometry/mass spectrometry (LC-MS/MS) for theacrine, caffeine, and paraxanthine. Pharmacodynamic response markers, heart rate and blood pressure, were recorded. Results: Theacrine p...

Within the fitness community there is an unsubstantiated concern that adherence to a plant-based diet results in low circulating testosterone in men, with minimal potential for gains in Lean Body Mass (LBM). We addressed this concern using Long-Evans rats (N=28) assigned to experimental diets of plant (PD) or animal (AD) origin and fed ad libitum for 12 weeks. Animals were further divided into two additional conditions with (E) and without exercise (S). We measured total circulating testosterone and estradiol, and body composition was assessed using dual energy x-ray absorptiometry. Neither totaltestosterone (1.7±0.2 vs. 1.6±0.2 ng·mL-1) nor LBM (384±6 vs. 377±6 g) differed between rats fed the PD or AD diets, respectively, apart from PD+E having higher LBM as compared to AD+E (p=0.03). PD rats were significantly leaner than AD rats, based on body fat (22.4±1.0% vs 32.1±0.8%; p Keywords: Animal Protein; Body Composition; Exercise; Hormones; Plant Protein; Vegan; Western Diet

Methylsulfonylmethane (MSM) has become a popular dietary supplement used for a variety of purposes, including its most common use as an anti-inflammatory agent. It has been well-investigated in animal models, as well as in human clinical trials and experiments. A variety of health-specific outcome measures are improved with MSM supplementation, including inflammation, joint/muscle pain, oxidative stress, and antioxidant capacity. Initial evidence is available regarding the dose of MSM needed to provide benefit, although additional work is underway to determine the precise dose and time course of treatment needed to provide optimal benefits. As a Generally Recognized As Safe (GRAS) approved substance, MSM is well-tolerated by most individuals at dosages of up to four grams daily, with few known and mild side effects. This review provides an overview of MSM, with details regarding its common uses and applications as a dietary supplement, as well as its safety for consumption.

This paper provides an overview of the current literature and scientific evidence surrounding inorganic nitrate (NO3−) supplementation and its potential for improving human health and physical performance. As indicative of the ever-expanding organic and natural food consumer market, athletes and health enthusiasts alike are constantly searching for ingredient-specific “super foods” and dietary supplements capable of eliciting health and performance benefits. Evidence suggests that NO3− is the viable active component within beetroot juice (BRJ) and other vegetables, responsible for health-promoting and ergogenic effects. Indeed, multiple studies support NO3− supplementation as an effective method to improve exercise performance. NO3− supplementation (either as BRJ or sodium nitrate [NaNO3−]) has also demonstrated modest benefits pertaining to cardiovascular health, such as reducing blood pressure (BP), enhancing blood flow, and elevating the driving pressure of O2 in the microcirculation to areas of hypoxia or exercising tissue. These findings are important to cardiovascular medicine/exercise physiology and suggest a possible role for NO3− supplementation: (1) as a low-cost prevention and treatment intervention for patients suffering from blood flow disorders; and (2) an effective, natural ergogenic aid for athletes. Benefits have been noted following a single bolus, as well as daily supplementation of NO3−. While results are promising, additional research is needed to determine the impact of NO3− supplementation on anaerobic exercise performance, to identify principle relationships between isolated nitrate and other ingredients found in nitrate-rich vegetables (e.g., vitamin C, polyphenols, fatty acids, thiocyanate), to explore the specific dose-response relationships needed to elicit health and ergogenic benefits, to prolong the supplementation period beyond a relatively short period (i.e., >15 days), to determine if more robust effects can be observed with longer-term treatment, and to fully examine the safety of chronic NO3− supplementation, as this continues to be a concern of some.

Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal. To compare the impact of acute exercise on postprandial oxidative stress. We compared aerobic and anaerobic exercise bouts of different intensities and durations on postprandial blood triglycerides (TAG), oxidative stress biomarkers (malondialdehyde, hydrogen peroxide, advanced oxidation protein products), and antioxidant status (trolox equivalent antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase). Twelve trained men (21–35 years) underwent four conditions: (1) No exercise rest; (2) 60-min aerobic exercise at 70 % heart rate reserve; (3) five 60-s sprints at 100 % max capacity; and (4) ten 15-s sprints at 200 % max capacity. All exercise bouts were performed on a cycle ergometer. A high-fat meal was consumed 1 h after exercise cessation. Blood samples were collected pre-meal and 2 and 4 h post-meal and analyzed for TAG, oxidative stress biomarkers, and antioxidant status. No significant interaction or condition effects were noted for any variable (p > 0.05), with acute exercise having little to no effect on the magnitude of postprandial oxidative stress. In a sample of healthy, well-trained men, neither aerobic nor anaerobic exercise attenuates postprandial oxidative stress in response to a high-fat meal.

Background: The effectiveness of L-carnitine supplementation has been met with conflicting findings when used by sedentary and athletic adults. Objectives: This study aimed to investigate the acute effects of L-carnitine supplementation on aerobic metabolic efficiency and lipid profiles in sedentary and athletic men. Methods: Fifteen sedentary (20.4 ± 1.5 years) and 15 athletic (21.5 ± 2.4 years) men were studied in durations of control, placebo intake and 2 g of L-carnitine supplementation. Lipid profiles, including triglyceride, cholesterol, high-density lipoprotein (HDL) and very-low density lipoprotein (VLDL), were determined before and 40 min after either the placebo or L-carnitine intake. Oxygen consumption (direct VO2), ventilatory threshold (VT), and running time (RT) were recorded after a submaximal treadmill exercise test. Results: Direct VO2 increased significantly at 80% of maximal heart rate after L-carnitine supplementation in both athletic and sedentary men, whereas, a statistical increase in VT and RT occurred only after L-carnitine use in athletes, when compared to the control and placebo subjects. The sedentary group showed no changes in lipid parameters, but triglyceride levels reduced significantly in the athletes after consuming L-carnitine. Conclusions: Acute L-carnitine supplementation possibly affects exercise performance and triglycerides in athletes rather than sedentary men.

OBJECTIVES: The gut microbiome participates in host metabolic regulation. While the vast majority of microbiome research has focused on bacterial populations, other microorganisms also colonize the mammalian intestine and likely play functionally important roles in host metabolism. The objective of current study was to characterize the role of dietary composition and timing strategies upon gut fungal populations. METHODS: C57BL/6 male mice were randomized to a Chow diet or a high-fat diet (HFD) for 6 weeks, followed by a switch from HFD to 1) Chow (sChow), 2) Purified High Fiber – Daniel Fast (DF), 3) HFD ad lib, 4) HFD time restricted (TRF), 5) HFD alternative day fasting (ADF), or 6) HFD 60% caloric restriction (CR) for an additional 8 weeks. Ileal, cecal and serial fecal samples were collected for next generation sequencing of ITS2 rRNA to examine the gut mycobiome. RESULTS: We observed dramatic reductions in alpha diversity in fecal fungal populations when animals consumed the HFD compared with Chow. HFD resulted in dramatic reduction in the relative abundance of the fungal order Saccharomyces, with a concomitant increases in the genus Candida and Hanseniaspora. In response to dietary switch from HFD to Chow, fungal taxonomic composition, alpha, and beta diversity transitioned to a population clustering more similarity with Chow by weeks 4 and 8 of intervention. After 8 weeks on the respective dietary interventions, alpha diversity of the ileal, cecal and fecal fungal population in mice consuming DF or various HFD fasting protocols remained similar to the HFD controls. Saccharomycetales remained the dominant genus present in HFD and DF groups. However, amongst these groups, the DF group (fecal sample) showed the greatest increase in Saccharomyces, but time-restricted feeding protocols also showed increased levels of Saccharomyces. CONCLUSIONS: While fasting protocols on HFD are associated with improved metabolic outcomes, these data demonstrate that – similar to microbial populations within the microbiome – diet remains the largest driver of microorganism community composition. To our knowledge, this is the first investigation into the role of dietary timing strategies upon the gut fungal communities ever reported. FUNDING SOURCES: University of Memphis. Children's Foundation Research Institute, Memphis.

Time-restricted feeding (TRF), alternate day fasting (ADF), and the dietary restriction model known as the Daniel Fast (DF, a vegan/non-processed food diet plan) have garnered attention recently as nutritional interventions to combat obesity. We compared the effects of various dietary models on body composition, physical performance, and metabolic health in C57BL/6 mice. Sixty young C57BL/6 male mice were assigned a diet of TRF, ADF, DF, caloric restriction (CR), a high-fat Western diet (HF) fed ad libitum, or standard rodent chow for eight weeks. Their body composition, run time to exhaustion, fasting glucose, insulin, and glucose tolerance test area under the glucose curve (AUC) were determined. Compared to the HF group, all groups displayed significantly less weight and fat mass gain, as well as non-significant changes in fat-free mass. Additionally, although not statistically significant, all groups displayed greater run time to exhaustion relative to the HF group. Compared to the HF group, all groups demonstrated significantly lower fasting glucose, insulin, and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), as well as improved glucose tolerance, and the ADF group displayed the best fasting glucose and glucose tolerance results, with DF having the best HOMA-IR. All investigated fasting protocols may improve body composition, measures of insulin sensitivity, and physical performance compared to a high-fat Western diet. The DF and ADF protocols are most favorable with regards to insulin sensitivity and glucose tolerance. Since our selected dietary protocols have also been investigated in humans with success, it is plausible to consider that these dietary models could prove beneficial to men and women seeking improved body composition and metabolic health.

Intensity of exercise can influence substrate utilization, with increasing intensity resulting in lower rates of fat oxidation and the reliance on carbohydrate as the preferred fuel. Fat oxidation (or more specifically, mobilization) can be assessed via the measurement of circulating glycerol, with most prior research focusing on aerobic exercise and measurements obtained during the actual exercise bout. The present study determined the degree of fat oxidation/mobilization by measuring plasma glyctierol concentrations during the one hour post-exercise recovery period following three difference exercise bouts. On four different days, exercise trained men (n=12; 23.7±1.1 years) either rested quietly or performed aerobic cycle exercise (60 min at 70% heart rate reserve), 60 s cycle sprints at 100% max wattage obtained during graded exercise testing (GXT) - a total of five, or 15 s cycle sprints at 200% max wattage obtained during GXT - a total of 10. Blood was collected before and at 1, 30 and 60 min post-exercise. Haematocrit and haemoglobin were measured to correct for changes in plasma volume. Glycerol was analysed in plasma and the area under the curve was calculated. Glycerol increased across time (P