Nieman DC, Shanely RA, Luo B, Meaney MP, Dew DA, Pappan KL. Metabolomics approach to assessing plasma 13-and 9-hydroxy-octadecadienoic acid and linoleic acid metabolite responses to 75-km cycling. Am J Physiol Regul Integr Comp Physiol 307: R68 -R74, 2014. First published April 23, 2014 doi:10.1152/ajpregu.00092.2014.-Bioactive oxidized linoleic acid metabolites (OXLAMs) include 13-and 9-hydroxy-octadecadienoic acid (13-HODE ϩ 9-HODE) and have been linked to oxidative stress, inflammation, and numerous pathological and physiological states. The purpose of this study was to measure changes in plasma 13-HODE ϩ 9-HODE following a 75-km cycling bout and identify potential linkages to linoleate metabolism and established biomarkers of oxidative stress (F2-isoprostanes) and inflammation (cytokines) using a metabolomics approach. Trained male cyclists (N ϭ 19, age 38.0 Ϯ 1.6 yr, wattsmax 304 Ϯ 10.5) engaged in a 75-km cycling time trial on their own bicycles using electromagnetically braked cycling ergometers (2.71 Ϯ 0.07 h). Blood samples were collected preexercise, immediately post-, 1.5 h post-, and 21 h postexercise, and analyzed for plasma cytokines (IL-6, IL-8, IL-10, tumor necrosis factor-␣, monocyte chemoattractant protein-1, granulocyte colonystimulating factor), F2-isoprostanes, and shifts in metabolites using global metabolomics procedures with gas chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS). 13-HODE ϩ 9-HODE increased 3.1-fold and 1.7-fold immediately post-and 1.5 h postexercise (both P Ͻ 0.001) and returned to preexercise levels by 21-h postexercise. Post-75-km cycling plasma levels of 13-HODE ϩ 9-HODE were not significantly correlated with increases in plasma cytokines but were positively correlated with postexercise F 2-isoprostanes (r ϭ 0.75, P Ͻ 0.001), linoleate (r ϭ 0.54, P ϭ 0.016), arachidate (r ϭ 0.77, P Ͻ 0.001), 12,13-dihydroxy-9Z-octadecenoate (12,13-DiHOME) (r ϭ 0.60, P ϭ 0.006), dihomo-linolenate (r ϭ 0.57, P ϭ 0.011), and adrenate (r ϭ 0.56, P ϭ 0.013). These findings indicate that prolonged and intensive exercise caused a transient, 3.1-fold increase in the stable linoleic acid oxidation product 13-HODE ϩ 9-HODE and was related to increases in F 2-isoprostanes, linoleate, and fatty acids in the linoleate conversion pathway. These data support the use of 13-HODE ϩ 9-HODE as an oxidative stress biomarker in acute exercise investigations.

ObjectivesPistachio nut ingestion (3 oz./d, two weeks) was tested for effects on exercise performance and 21-h post-exercise recovery from inflammation, oxidative stress, immune dysfunction, and metabolite shifts.MethodsUsing a randomized, crossover approach, cyclists (N = 19) engaged in two 75-km time trials after 2-weeks pistachio or no pistachio supplementation, with a 2-week washout period. Subjects came to the lab in an overnight fasted state, and ingested water only or 3 oz. pistachios with water before and during exercise. Blood samples were collected 45 min pre-exercise, and immediately post-, 1.5-h post-, and 21-h post-exercise, and analyzed for plasma cytokines, C-reactive protein (CRP), F2-isoprostanes (F2-IsoP), granulocyte phagocytosis (GPHAG) and oxidative burst activity (GOBA), and shifts in metabolites.ResultsPerformance time for the 75-km time trial was 4.8% slower under pistachio conditions (2.84±0.11 and 2.71±0.07 h, respectively, P = 0.034). Significant time effects were shown for plasma cytokines, CRP, F2-IsoP, GPHAG, and GOBA, with few group differences. Metabolomics analysis revealed 423 detectable compounds of known identity, with significant interaction effects for 19 metabolites, especially raffinose, (12Z)-9,10-Dihydroxyoctadec-12-enoate (9,10-DiHOME), and sucrose. Dietary intake of raffinose was 2.19±0.15 and 0.35±0.08 mg/d during the pistachio and no pistachio periods, and metabolomics revealed that colon raffinose and sucrose translocated to the circulation during exercise due to increased gut permeability. The post-exercise increase in plasma raffinose correlated significantly with 9,10-DiHOME and other oxidative stress metabolites.ConclusionsIn summary, 2-weeks pistachio nut ingestion was associated with reduced 75-km cycling time trial performance and increased post-exercise plasma levels of raffinose, sucrose, and metabolites related to leukotoxic effects and oxidative stress.Trial RegistrationClinicalTrials.gov NCT01821820

This study validated the accuracy of COSMED's Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system in measuring metabolic factors during maximal, graded exercise testing. Subjects included 32 physically active men between the ages of 18 and 34 years. During the first test session, subjects were measured for maximal oxygen consumption twice (15 min separation) with the CPET and Douglas bag systems (random order). During the second test session, subjects exercised through four stages of the Bruce treadmill protocol with measurement by the CPET and Douglas bag systems (random order) during steady state at the end of each 3-minute stage. Statistical analysis using a 2 (systems) x 5 (time) repeated measures ANOVA showed that the pattern of change in VO2, VCO2, VE, FeO2, FeCO2, and RER did not differ significantly between CPET and Douglas bag systems. This validation study indicates that the CPET mixing chamber system provides valid metabolic measurements that compare closely with the Douglas bag system during aerobic exercise.

Functional overreaching has been linked to alterations in immunity and host pathogen defense, but little is known as to whether or not running and cycling evoke different responses. This study compared inflammation, muscle damage and soreness, and innate immune function responses to a 3-day period of intensified exercise in trained long distance runners (N=13, age 34.4±2.4year) and cyclists (N=22, age 36.6±1.7year, P=0.452). Upper respiratory tract infection (URTI) symptomatology was monitored for 12weeks using the Wisconsin Upper Respiratory Symptom Survey (WURSS), and subjects from both athletic groups came to the lab during week five and exercised 2.5h/day for 3days in a row at 70% VO2max. Blood samples were collected before and after the 3-day period of exercise, with recovery samples collected 1-, 14-, and 38h-post-exercise. Samples were analyzed for muscle damage [creatine kinase (CK), myoglobin (MYO)], inflammation (CRP, IL-6, IL-8, IL-10, MCP), and innate immunity [granulocyte and monocyte phagocytosis (GR-PHAG and MO-PHAG) and oxidative burst activity (GR-OBA and MO-OBA)]. Runners compared to cyclists experienced significantly more muscle damage (CK 133% and MYO 404% higher post-3days exercise), inflammation (CRP 87%, IL-6 256%, IL 8 61%, IL-10 32%, MCP 29%), and delayed onset of muscle soreness (DOMS, 87%). The 3-day period of exercise caused significant downturns in GR-PHAG, MO-PHAG, GR-OBA, MO-OBA by 14- and 38h-recovery, but the pattern of change did not differ between groups. No group differences were measured for 12-week URTI severity (18.3±5.6 and 16.6±4.0, P=0.803) and symptom scores (33.4±12.6 and 24.7±5.8, P=0.477). These data indicate that a 3-day period of functional overreaching results in substantially more muscle damage and soreness, and systemic inflammation in runners compared to cyclists, but without group differences for 12-week URTI symptomatology and post-exercise decrements in innate immune function.

This study determined if 6-weeks vitamin D2 supplementation (vitD2, 3800 IU/day) had an influence on muscle function, eccentric exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) in National Association for Stock Car Auto Racing (NASCAR) NASCAR pit crew athletes. Subjects were randomized to vitD2 (n = 13) and placebo (n = 15), and ingested supplements (double-blind) for six weeks. Blood samples were collected and muscle function tests conducted pre- and post-study (leg-back and hand grip dynamometer strength tests, body weight bench press to exhaustion, vertical jump, 30-s Wingate test). Post-study, subjects engaged in 90 min eccentric-based exercise, with blood samples and DOMS ratings obtained immediately after and 1- and 2-days post-exercise. Six weeks vitD2 increased serum 25(OH)D2 456% and decreased 25(OH)D3 21% versus placebo (p < 0.001, p = 0.036, respectively), with no influence on muscle function test scores. The post-study eccentric exercise bout induced EIMD and DOMS, with higher muscle damage biomarkers measured in vitD2 compared to placebo (myoglobin 252%, 122% increase, respectively, p = 0.001; creatine phosphokinase 24 h post-exercise, 169%, 32%, p < 0.001), with no differences for DOMS. In summary, 6-weeks vitD2 (3800 IU/day) significantly increased 25(OH)D2 and decreased 25(OH)D3, had no effect on muscle function tests, and amplified muscle damage markers in NASCAR pit crew athletes following eccentric exercise.