Biomedical subjects

David C Nieman

Publications and source records attributed to David C Nieman.

At least 19 recordsLinked to original sources

PubMed2025

Multi-omics signature of healthy versus unhealthy lifestyles reveals associations with diseases.

This multi-omics cross-sectional study investigated differences in metabolomics, proteomics, and epigenomics profiles between two groups of adults matched for age but differing in lifestyle factors such as body composition, diet, and physical activity patterns. Data from prior studies were utilized for a comprehensive integrative analysis. The study included 52 participants in the lifestyle group (LIFE) (28 males, 24 females) and 52 in the control group (CON) (27 males, 25 females). Using multi-omics integration software (OmicsNet and Pathview), 96 significantly (p < 0.05) enriched pathways were identified that differentiated the LIFE and CON groups. Top pathways significantly (p < 2.63 × 10-5) influenced by group status included fatty acid degradation, fatty acid elongation, glutathione metabolism, Parkinson disease, and central carbon metabolism in cancer. This study identified a distinct metabolic signature comprised of metabolites, proteins, and gene methylation sites associated with a healthy lifestyle. These findings provide unique, but complementary, results to previous single-omics analyses using metabolomics and proteomics procedures which showed that the LIFE group exhibited lower plasma bile acid levels, higher levels of beneficial fatty acids, reduced innate immune activation, enhanced lipoprotein metabolism, and increased HDL remodeling. The current multi-omics analysis builds on these previous results by providing a more holistic view of how metabolites, proteins, and methylation sites associated with a healthy lifestyle, providing a larger, more comprehensive list of altered pathways. Additionally, the integrated analysis revealed connections between lifestyle factors and conditions such as cancer and insulin resistance beyond what identified in the single-omics approaches, highlighting the broader metabolic impact of lifestyle on health. Overall, the signatures identified by this multi-omics approach provide a basis for developing more translational biomarkers, such as those that defined the cancer and insulin resistance pathways that can be used to assess one's state of health and provide guidance on behavior modifications that should be taken to lower disease risk.

Humans↗

PubMed2006

Ibuprofen use, endotoxemia, inflammation, and plasma cytokines during ultramarathon competition.

The primary purpose of this study was to measure the influence of ibuprofen use during the 160-km Western States Endurance Run on endotoxemia, inflammation, and plasma cytokines. Subjects included 29 ultramarathoners who consumed 600 and 1200 mg ibuprofen the day before and on race day, respectively, and 25 controls that competed in the race but avoided ibuprofen and all other medications. Blood and urine samples were collected the morning prior to and immediately following the race, and subjects recorded muscle soreness during the week following the race using a 10-point Likert scale (DOMS). Race time (25.8+/-.6 and 25.6+/-.8 h, respectively) and ratings of perceived exertion (RPE, 6-20 scale) (14.6+/-.4 and 14.5+/-.2, respectively) did not differ significantly between ibuprofen users and nonusers. Ibuprofen use compared to nonuse was linked to a smaller increase in urine creatinine (P=.038), higher plasma levels of lipopolysaccharide (group effect, P=.042), and greater increases (pre-to-post race) in serum C-reactive protein and plasma cytokine levels for interleukin (IL)-6, IL-10, IL-8, IL-1 ra, granulocyte colony-stimulating factor, monocyte chemotactic protein 1, and macrophage inflammatory protein 1 beta, but not tumor necrosis factor alpha. Post-race DOMS and serum creatine kinase levels did not differ significantly between ibuprofen users and nonusers (20,621+/-3565 and 13,886+/-3068 microcal/L, respectively, P=.163). In conclusion, ibuprofen use compared to nonuse by athletes competing in a 160-km race did not alter muscle damage or soreness, and was related to elevated indicators of endotoxemia and inflammation.

Adult↗

PubMed2006

Nutritional strategies to counter stress to the immune system in athletes, with special reference to football.

Although epidemiological data indicate that athletes are at increased risk of upper respiratory tract infection during periods of heavy training and the 1 - 2 week period following endurance race events, there is very limited information on the responses to football training and match-play. For several hours after heavy exertion, components of both the innate (e.g. natural killer cell activity and neutrophil oxidative burst activity) and adaptive (e.g. T and B cell function) immune system exhibit suppressed function. Although such responses to football training and competition do not appear to be as pronounced, variations in immune cell numbers and function are reported in professional footballers over the course of a season. Attempts have been made through nutritional means (e.g. glutamine, vitamins C and E, and carbohydrate supplementation) to attenuate immune changes following intensive exercise and thus lower the risk of upper respiratory tract infection. Carbohydrate supplementation during heavy exercise has emerged as a partial countermeasure and attenuates increases in blood neutrophil counts, stress hormones, and inflammatory cytokines, but has little effect on decrements in salivary IgA output or natural killer cell function. Animal research indicates that other nutritional components such as beta-glucan, quercetin, and curcumin warrant human investigations to determine if they are effective countermeasures to exercise-induced immune dysfunction.

Humans↗

PubMed2006

Blood leukocyte mRNA expression for IL-10, IL-1Ra, and IL-8, but not IL-6, increases after exercise.

The primary purpose of this project was to study exercise-induced leukocyte cytokine mRNA expression. Changes in plasma cytokine levels and blood leukocyte mRNA expression for interleukin-6 (IL-6), IL-8, IL- 10, and IL-1 receptor antagonist (IL-1Ra) were measured in 12 athletes following 2 h of intensive cycling ( approximately 64% Watts(max)) while ingesting a carbohydrate or placebo beverage (randomized and double blinded). Blood samples were collected 30 min preexercise and immediately and 1 h postexercise. Carbohydate compared with placebo ingestion attenuated exercise-induced changes in plasma cortisol (8.8% vs. 62%, respectively), epinephrine (-9.2% vs. 138%), IL-6 (10-fold vs. 40-fold), IL-10 (8.9-fold vs. 26-fold, and IL-1Ra (2.1-fold vs. 5.6-fold). Significant time effects were measured for blood leukocyte IL-8 (2.4-fold increase 1 h postexercise), IL-10 (2.7-fold increase), IL-1Ra (2.2-fold increase), and IL-6 (0.8-fold decrease) mRNA content, with no significant differences between Cho and Pla test conditions. In summary, gene expression for IL-8, IL-10, and IL-1Ra, but not IL-6, is increased in blood leukocytes taken from athletes following 2 h of intensive cycling and is not influenced by carbohydrate compared with placebo ingestion. mRNA expression was high enough to indicate a substantial contribution of blood leukocytes to plasma levels of IL-8, IL-10, and IL-1Ra during prolonged exercise.

Adult↗

PubMed2006

Validation of Omni scale of perceived exertion during prolonged cycling.

PURPOSE: The present investigation was conducted to validate the OMNI ratings of perceived exertion (RPE) scale during prolonged cycle exercise when subjects were supplemented with either carbohydrate or placebo. METHODS: Fifteen trained cyclists cycled for 2.5 h at approximately 60% maximal watts on two occasions while receiving 4 mL x kg(-1) x 15 min(-1) carbohydrate (6%) (C) or placebo (P) beverages in a randomized, counterbalanced design. Concurrent and construct validity was established by evaluating perceptual responses with both the OMNI and Borg RPE scales every 20 min throughout the trials. RESULTS: The pattern of change in RPE over time was significantly different between C and P ingestion (P < 0.05), with an attenuated RPE response in C found at the hundredth minute for both the OMNI and Borg scales. The pattern of change in the respiratory exchange ratio and carbohydrate oxidation rates were significantly greater (P < 0.001) in the C than P condition. RPE-OMNI was positively and linearly related to the RPE-BORG; r = 0.60-0.98 (P < 0.01) throughout exercise for both the C and P conditions. CONCLUSIONS: Concurrent and construct evidence supports the use of the OMNI-cycle scale by adult men to estimate RPE during prolonged cycle exercise under differing conditions of carbohydrate supplementation.

Adult↗

PubMed2005

Muscle damage is linked to cytokine changes following a 160-km race.

Muscle damage and perceived soreness following the 160-km Western States Endurance Run were related to changes in plasma cytokines and use of nonsteroidal anti-inflammatory drugs (NSAIDS). Subjects included 60 ultramarathoners (mean+/-SE, age 45.3 +/- 1.1 years) who finished the race in under 30 h (26.3 +/- 0.4 h). Blood samples were collected the morning prior to and immediately following the race, and subjects recorded muscle soreness during the week following the race using a 10-point Likert scale (DOMS). Seven plasma cytokines were measured including IL-6, IL-10, IL-8, IL-1ra, granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein 1 (MCP-1), and macrophage inflammatory protein 1beta (MIP-1beta). Cytokine changes were compared between NSAID users and nonusers, and correlated with creatine phosphokinase (CPK) and DOMS. Significant increases were measured for all seven cytokines, with the greatest fold increases seen for IL-6 (125x), IL-10 (24x), and G-CSF (12x). CPK was correlated with changes in IL-6, G-CSF, IL-10, IL-1ra, and MCP-1 (r = .49-.68), (P < .001), but not IL-8 or MIP-1beta. DOMS averaged 7.1 +/- 0.3 the day after the race, and 5.0 +/- 0.3, 2.5 +/- 0.2, and 1.6 +/- 0.1 3 days, 5 days, and 7 days post-race, respectively, and each was correlated with CPK (r = .40-.63, P < .001) and changes in IL-6, G-CSF, IL-10, and MCP-1 (r = .28-.77, P < .05). A comparison of NSAID users (72% of athletes) and nonusers showed no differences in CPK or DOMS, but did reveal greater increases in five of seven cytokines in the NSAID users (P < .05). In conclusion, muscle damage in athletes competing in a 160-km race was significantly correlated with post-race DOMS and increases in five of seven cytokines. NSAID users did not experience a reduction in muscle damage or DOMS, but did have higher post-race plasma levels in five of seven cytokines.

Adult↗

PubMed2005

Effect of alpha-tocopherol supplementation on plasma homocysteine and oxidative stress in highly trained athletes before and after exhaustive exercise.

The interrelationship between physical exercise, antioxidant supplementation, oxidative stress and plasma levels of homocysteine (Hcy) has not been adequately examined. The purpose of this study was to examine the effect of 2 months of vitamin E supplementation (800 IU/day alpha-tocopherol) (E) or placebo (P) in 38 triathletes on plasma Hcy concentrations, antioxidant potential and oxidative stress. It was hypothesized that vitamin E supplementation would reduce plasma Hcy and oxidative stress markers compared to placebo. Blood samples were collected 1 day prior to the race, immediately postrace and 1.5 h postrace. Plasma alpha-tocopherol was 75% higher (P<.001) in E versus P prerace (24.1+/-1.1 and 13.8+/-1.1 micromol/L, respectively), and this group difference was maintained throughout the race. Cortisol was significantly increased in both E and P (P<.001), but there was no difference in the pattern of change. There were no significant time, group or interaction effects on plasma Hcy concentrations between E and P. Plasma F(2)-isoprostanes increased 181% versus 97% during the race in E versus P, and lipid hydroperoxides were significantly elevated (P=.009) 1.5 h postrace in E versus P. Plasma antioxidant potential was significantly higher 1.5 h postrace in E versus P (P=.039). This study indicates that prolonged large doses of alpha-tocopherol supplementation did not affect plasma Hcy concentrations and exhibited pro-oxidant characteristics in highly trained athletes during exhaustive exercise.

Adult↗

PubMed2005

Effect of resistance exercise and carbohydrate ingestion on oxidative stress.

Some research studies have produced data indicating that resistance exercise induces oxidative stress, despite minimal increases in VO(2). These studies have primarily relied on oxidative stress markers with low sensitivity and debatable reliability. However, F(2)-isoprostanes as measured by gas chromatography mass spectrometry are considered to be a reliable and precise indicator of oxidative stress. Carbohydrate ingestion during exercise is associated with reduced levels of stress hormones, which may influence oxidative stress and plasma antioxidant potential. Therefore, the purpose of this study was to investigate the influence of carbohydrate ingestion during resistance training on F(2)-isoprostanes and plasma antioxidant potential. Thirty strength-trained subjects were randomized to carbohydrate (CHO) or placebo (PLA) groups that lifted weights for 2 h. Subjects received 10 ml kg(- 1) h(- 1) CHO (6%) or PLA beverages during the exercise. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise and analyzed for cortisol as a marker of general stress, F(2)-isoprostanes as a measure of oxidative stress, and ferric reducing ability of plasma (FRAP) as a measure of antioxidant potential, and for muscle glycogen, respectively. Decreases in muscle glycogen content did not differ between CHO and PLA. Cortisol and FRAP increased significantly in CHO and PLA (P = 0.008 and 0.044, respectively), but the pattern of change was not different between groups. F(2)-isoprostanes were unaffected by exercise. These results indicate that exhaustive resistance exercise and carbohydrate ingestion have no effect on oxidative stress or plasma antioxidant potential in trained subjects.

Adult↗

PubMed2005

Validation of a new handheld device for measuring resting metabolic rate and oxygen consumption in children.

The purpose of this study was to assess the validity and reliability of the MedGem device to measure resting metabolic rate (RMR) in children. Subjects included 59 children (29 boys, 30 girls; mean age, 11.0 +/- 0.2 y). Subjects were given 4 RMR tests during 1 test session, cconsisting of 2 Douglas bag and 2 MedGem tests, in random counterbalanced order. No significant differences were found between Douglas bag and MedGem systems for oxygen consumption (209 +/- 5 and 213 +/- 5 mL/min, respectively, P = 0.106, r = 0.911, mean +/- standard deviation absolute difference 3.72 +/- 17.40 mL/min) or RMR (1460 +/- 39 and 1477 +/- 35 kcal/d, P = 0.286, r = 0.909, mean +/- standard deviation absolute difference 17.4 +/- 124 kcal/d). Standard error of estimates for oxygen consumption and RMR were 17.4 mL/min and 124 kcal/d, respectively. In conclusion, these data indicate that the MedGem is a reliable and valid system for measuring oxygen consumption and RMR in children.

Adolescent↗

PubMed2005

Immune response to a 30-minute walk.

PURPOSE: To measure several components of immune changes related to walking 30 min with or without an exercise assist device compared with sitting. METHODS: Fifteen healthy and nonobese female subjects (37.5 +/- 3.1 yr of age) accustomed to regular walking were recruited and tested for aerobic power (VO(2max) 34.4 +/- 1.4 mL.kg(-1).min(-1)). During three randomly assigned 30-min test sessions, subjects functioned as their own controls and either sat in the laboratory, walked at approximately 60% VO(2max), or walked at the same treadmill speed using the BODY BAT Aerobic Exerciser. This exercise assist device resembles a pair of baseball bats seamlessly joined together and is held with both hands and swung to shoulder height across the body in a natural side to side pendulum motion. Saliva and blood samples were collected pre- and postexercise, and 1 h postexercise, with the data statistically analyzed using a 3 x 3 repeated measures ANOVA. RESULTS: Walking with the exercise assist device increased oxygen consumption 11 +/- 2% and heart rate 8 +/- 2 beats.min(-1). The pattern of increase in blood counts for neutrophils, lymphocytes, monocytes, and natural killer cells, plasma interleukin-6 concentration, and PHA-induced lymphocyte proliferation differed significantly when comparing walking with sitting, but no differences were found between walking with or without the exercise assist device. No significant increases over time or interaction effects were measured for plasma cortisol concentration, salivary IgA output, or plasma interleukin-1 receptor antagonist concentration. CONCLUSIONS: The use of an exercise assist device increased oxygen consumption 11% during walking, but did not alter the pattern of change in several components of immunity measured during walking alone in comparison to sitting. Walking caused modest and short-lived changes in immune parameters, most notably for neutrophil and natural killer blood cell counts.

Adult↗

PubMed2005

Evaluation of leg-to-leg BIA in assessing body composition of high-school wrestlers.

PURPOSE: To evaluate the accuracy of leg-to-leg bioelectrical impedance analysis (BIA) in assessing fat-free mass (FFM) using the TBF-300WA in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high-school (HS) wrestlers in a hydrated state. METHODS: Body composition was determined by BIA, HW, and three-site SK in 129 HS wrestlers (mean +/- SD, age: 15.5 +/- 1.3, height 1.70 +/- 0.08 m, body mass 65.6 +/- 13.1 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity. RESULTS: There were no significant differences for estimated FFM between BIA (56.9 +/- 8.4 kg) and HW (56.2 +/- 9.9 kg) or between SK (56.1 +/- 8.9 kg) and HW. The standard errors of estimate for FFM with HW as the reference method were 3.64 kg for BIA and 1.97 kg for SK. Significant correlations were found for FFM between HW and BIA (r = 0.93, P < 0.001), and between HW and SK (r = 0.98, P < 0.001). The FFM difference between BIA and HW was significantly correlated with the FFM average of the two methods (r = -0.39, P < 0.001). The FFM difference between SK and HW was also significantly correlated with the FFM average (r = -0.44, P < 0.001). CONCLUSIONS: This study demonstrates that SK should be considered as the preferred field method of estimating the FFM of HS wrestlers because of its greater individual precision than the leg-to-leg BIA method. Although the BIA is an attractive assessment tool and easy to use, it should be recommended as an alternative to the SK method only when trained skinfold technicians are not available.

Adolescent↗

PubMed2005

Muscle cytokine mRNA changes after 2.5 h of cycling: influence of carbohydrate.

PURPOSE: To study the effect of carbohydrate compared to placebo ingestion on plasma cytokines and muscle cytokine mRNA following 2.5 h of intensive cycling in 15 trained cyclists. METHODS: Fifteen trained cyclists cycled for 2.5 h at 60% Wmax on two occasions while receiving 4 mL.kg.15 min carbohydrate (6%) (CHO) or placebo (PLA) beverages in a randomized, counterbalanced design. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise and 12 h postexercise and compared to samples taken from five cyclists who rested in the lab during the exercise sessions. Blood cell counts were determined, and plasma was analyzed for interleukin (IL)-6, IL-10, IL-1 receptor antagonist (ra), IL-8, cortisol, epinephrine, glucose, and insulin. Muscle was analyzed for glycogen content and relative gene expression of four cytokines, IL-6, IL-8, tumor necrosis factor (TNF) alpha, and IL-1beta, using real-time quantitative reverse transcriptase polymerase chain reaction. RESULTS: Plasma glucose and insulin were higher, and epinephrine, cortisol, IL-6, IL-10, and IL-1ra, but not IL-8, were significantly lower postexercise in CHO versus PLA. Muscle glycogen content decreased 68% immediately postexercise and the pattern of change did not differ between CHO and PLA. Muscle IL-6, IL-8, TNF-alpha, but not IL-1beta mRNA increased immediately postexercise compared to controls, with no differences between CHO and PLA. CONCLUSION: CHO compared to PLA beverage ingestion attenuated the increase in plasma cortisol, epinephrine, IL-6, IL-10, and IL-1ra, but not muscle IL-6, IL-8, and TNF-alpha mRNA in athletes cycling 2.5 h at 60% Wmax.

Bicycling↗

PubMed2005

Carbohydrate supplementation and perceived exertion during resistance exercise.

The purpose of the present study was to investigate the relationship between carbohydrate energy substrate and the perception of exertion during resistance exercise. Thirty strength-trained subjects were randomized to a carbohydrate group (C) or a placebo group (P), and lifted weights for 2 hours (4 sets; 10 repetitions maximum; 10 exercises; 2-3-minute rest intervals). Subjects ingested 10 ml.kg(-1).h(-1) of 6% carbohydrate or placebo beverages during the resistance-training bout. The 15-category Borg Perceived Exertion Scale was used to assess overall body (RPE-O) and active muscle (RPE-AM) perceived exertion after completion of the last repetition in each set for each exercise. No significant differences were found between the C and P groups for either RPE-O or RPE-AM, with the exception of RPE-O for the upright row and back squat (p < 0.05). Carbohydrate supplementation exerted no attenuating effect on ratings of perceived exertion (RPE) during resistance training.

Adult↗

PubMed2004

Exercise, nutrition and immune function.

Strenuous bouts of prolonged exercise and heavy training are associated with depressed immune cell function. Furthermore, inadequate or inappropriate nutrition can compound the negative influence of heavy exertion on immunocompetence. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction. An adequate intake of iron, zinc and vitamins A, E, B6 and B12 is particularly important for the maintenance of immune function, but excess intakes of some micronutrients can also impair immune function and have other adverse effects on health. Immune system depression has also been associated with an excess intake of fat. To maintain immune function, athletes should eat a well-balanced diet sufficient to meet their energy requirements. An athlete exercising in a carbohydrate-depleted state experiences larger increases in circulating stress hormones and a greater perturbation of several immune function indices. Conversely, consuming 30-60 g carbohydrate x h(-1) during sustained intensive exercise attenuates rises in stress hormones such as cortisol and appears to limit the degree of exercise-induced immune depression. Convincing evidence that so-called 'immune-boosting' supplements, including high doses of antioxidant vitamins, glutamine, zinc, probiotics and Echinacea, prevent exercise-induced immune impairment is currently lacking.

Exercise↗

PubMed2004

Influence of carbohydrate and age on lymphocyte function following a marathon.

The influence of 6% carbohydrate ingestion and age on PHA-induced lymphocyte proliferation and in vitro cytokine production was studied in 48 runners following a competitive marathon. Runners were randomly assigned to carbohydrate (C; n = 23) and placebo (P; n= 25) groups, with blood samples taken before, immediately after, and 1.5 hr post-race. C versus P ingestion resulted in higher plasma glucose, lower plasma cortisol, reduced neutrophilia, and monocytosis during recovery, but had no effect on the post-exercise reduction in T-lymphocytes or NK cells, or on race times. No group differences were observed for PHA-induced lymphocyte proliferation or cytokine production. However, for all subjects combined, lymphocyte proliferation and IFN-gamma secretion decreased significantly below pre-race values by 1.5 hr of recovery, and these were negatively correlated with plasma cortisol. Young (<50 years; n = 36) and old (>or=50 years; n = 12) runners exhibited parallel post-race declines in lymphocyte proliferation and IFN-gamma secretion, with the older group exhibiting a 33-59% lower proliferation at each time point. In conclusion, PHA-induced lymphocyte proliferation and cytokine production decreased significantly following a marathon, and this decrease was strongly linked to cortisol and only partially linked to T-cell changes. This decrease occurred in both younger and older runners and was not influenced by carbohydrate.

Adult↗

PubMed2004

Carbohydrate supplementation and perceived exertion during prolonged running.

PURPOSE: The purpose of this study was to investigate the relationship between carbohydrate energy substrate and hormonal regulation on the perception of exertion during prolonged running. METHODS: Sixteen experienced marathoners ran on treadmills for 3 h at approximately 70% VO2max on two occasions while receiving 1 L x h carbohydrate (C) or placebo (P) beverages. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise. RESULTS: The pattern of change in ratings of perceived exertion (RPE) over time was significantly different between C and P ingestion (P < 0.01) with attenuated RPE responses found in the latter part of the 3 h run. The pattern of change in the respiratory exchange ratio and carbohydrate oxidation rates were significantly greater (P < 0.01) in the C than P condition. Change in muscle glycogen content did not differ between C and P (P = 0.246). C relative to P ingestion was associated with higher plasma levels of glucose, insulin, and lactate and lower levels plasma cortisol. CONCLUSIONS: These data indicate that a lower RPE was associated with a higher carbohydrate oxidation, plasma glucose, and insulin levels, and lower plasma cortisol during prolonged running after C supplementation as compared with P feeding despite no differences in muscle glycogen content. These findings support a physiological link between RPE and carbohydrate substrate availability as well as selected hormonal regulation during prolonged running.

Adult↗

PubMed2004

Vitamin E and immunity after the Kona Triathlon World Championship.

PURPOSE: To measure the influence of vitamin E ingestion on oxidative stress and immune changes in response to the Triathlon World Championship in Kona, Hawaii. METHODS: Thirty-eight triathletes received vitamin E (VitE) (800 IU x d(-1) alpha-tocopherol) or placebo (Pla) capsules in randomized, double-blind fashion for 2 months before the race event. Blood, urine, and saliva samples were collected the day before the race, 5-10 min postrace, and 1.5 h postrace. RESULTS: Race times did not differ between VitE (N = 19, 721 +/- 24 min) and Pla groups (N = 17, 719 +/- 27 min, P = 0.959), and both groups maintained an intensity of approximately 80% maximum heart rate during the bike and run portions. Plasma alpha-tocopherol was approximately 75% higher in the VitE versus Pla group prerace (24.1 +/- 1.1 and 13.8 +/- 1.1 micromol x L(-1), P < 0.001, respectively) and postrace. Plasma F2-isoprostanes increased 181% versus 97% postrace in the VitE versus Pla groups (P = 0.044). IL-6 was 89% higher (166 +/- 28 and 88 +/- 13 pg x mL(-1), respectively, P = 0.016), IL-1ra was 107% higher (4848 +/- 1203 and 2341 +/- 790 pg x mL(-1), respectively, P = 0.057), and IL-8 was 41% higher postrace in the VitE versus Pla groups (26.0 +/- 3.6 and 18.4 +/- 2.4 pg x mL(-1), respectively, P = 0.094). CONCLUSION: These data indicate that vitamin E (800 IU x d(-1) for 2 months) compared with placebo ingestion before a competitive triathlon race event promotes lipid peroxidation and inflammation during exercise.

Adult↗

PubMed2004

Validation of the Adult OMNI Scale of perceived exertion for walking/running exercise.

PURPOSE: Concurrent and construct validity of the OMNI-Walk/Run Scale of Perceived Exertion was examined using young adult women and men (18-36 yr). METHODS: Concurrent validity was established by correlating OMNI-Walk/Run Scale ratings of perceived exertion (RPE-OMNI) with oxygen uptake (VO2), relative maximal oxygen uptake (%VO2(max)), ventilation (VE), respiratory rate (RR), respiratory exchange ratio (RER), and heart rate (HR) to a graded exercise test on a treadmill. Construct validity was established by correlating RPE-OMNI with RPE from the Borg (6-20) Scale (RPE-BORG). Measurements were made every min throughout the test. RESULTS: The range of exercise responses across the incremental walking/running test for the female and male groups were: VO2 = 0.99-3.9 L x min(-1), HR = 98-190 beats x min(-1) and RPE-OMNI = 1.3-9.4. Correlation/regression analyses indicated that RPE-OMNI distributed as a positive linear function for all criterion measures; r = 0.67 to 0.88 (P < 0.05). RPE-OMNI was positively and linearly related to the RPE-BORG; r = 0.96 (P < 0.01) for both the female and male groups. CONCLUSIONS: Concurrent and construct evidence supports use of the OMNI-Walk/Run Scale by adult women and men to estimate RPE during graded exercise test on a treadmill.

Adolescent↗