not entirely clear but have been linked to an increase in vascular endothelial growth factor (VEGF), nitric oxide (NO) bioavailability, hypoxic-inducible factor 1, and matrix metalloproteinase 9 ( 19 , 21 , 36 ). It is important to note that the release of EPCs in response to physical activity occurs
Livia Victorino Souza, Franciele De Meneck, Vanessa Oliveira, Elisa Mieko Higa, Eliana Hiromi Akamine and Maria do Carmo Franco
Zuhal Hamurcu, Nazmi Saritas, Gulden Baskol and Nese Akpinar
The objective of the current study is to determine the effects of regular wrestling exercise oxidative DNA damage and antioxidant parameters. The findings of the current study have shown that 8-hydroxy-2’-deoxyguanosine (8-OHdG) obtained from wrestlers in basal status were significantly lower than those of sedentary (p = .001). In contrast, Nitric oxide (NO) and Paraoxonase-1 (PON1) were remarkably higher in wrestlers in basal status than those of sedentary (respectively, p = .001, p = .024). While the NO of wrestlers increased immediately after a 1.5-h exercise compared with those before exercise (p = .002), no differences was found between before and immediately after a 1.5-h exercise in 8-OHdG and PON1 (respectively, p = .777, p = .408).Statistically significant correlations were found between the NO and PON1 in the wrestlers in basal status (r = .671, p = .002). In conclusion, our study suggests that wrestling exercise for a healthy life is important in that it reduces DNA damage as well as enhancing antioxidant parameters.
Darryn S. Willoughby, Tony Boucher, Jeremy Reid, Garson Skelton and Mandy Clark
Arginine-alpha-ketoglutarate (AAKG) supplements are alleged to increase nitric oxide production, thereby resulting in vasodilation during resistance exercise. This study sought to determine the effects of AAKG supplementation on hemodynamics and brachial-artery blood flow and the circulating levels of L-arginine, nitric oxide metabolites (NOx; nitrate/nitrite), asymmetric dimethyl arginine (ADMA), and L-arginine:ADMA ratio after resistance exercise.
Twenty-four physically active men underwent 7 days of AAKG supplementation with 12 g/day of either NO2 Platinum or placebo (PLC). Before and after supplementation, a resistance-exercise session involving the elbow flexors was performed involving 3 sets of 15 repetitions with 70–75% of 1-repetition maximum. Data were collected immediately before, immediately after (PST), and 30 min after (30PST) each exercise session. Data were analyzed with factorial ANOVA (p < .05).
Heart rate, blood pressure, and blood flow were increased in both groups at PST (p = .001) but not different between groups. Plasma L-arginine was increased in the NO2 group (p = .001). NOx was shown to increase in both groups at PST (p = .001) and at 30PST (p = .001) but was not different between groups. ADMA was not affected between tests (p = .26) or time points (p = .31); however, the L-arginine:ADMA ratio was increased in the NO2 group (p = .03).
NO2 Platinum increased plasma L-arginine levels; however, the effects observed in hemodynamics, brachial-artery blood flow, and NOx can only be attributed to the resistance exercise.
Emma M. Crum, Matthew J. Barnes and Stephen R. Stannard
accompanied by increased postexercise blood flow. The results of this study linked findings from previous investigations involving beetroot juice (BRJ). Both POMx and BRJ contain significant concentrations of nitrates (NO 3 − ), a precursor to the powerful vasodilator and signaling compound, nitric oxide (NO
Edgar J. Gallardo and Andrew R. Coggan
Numerous studies in recent years have investigated the effects of dietary nitrate (NO 3 − ) on the physiological responses to, and/or performance during, exercise. This interest stems from the fact that dietary NO 3 − is an important source of nitric oxide (NO) via the “reverse” NO 3 − → nitrite
Hannah Bond, Lillian Morton and Andrea J. Braakhuis
Increased plasma nitrate concentrations from dietary sources of nitrate have proven to benefit exercise performance. Beetroot (BR) contains relatively high levels of nitrate (NO3 −), which increases nitric oxide stores. This study investigated whether dietary nitrate supplementation, in the form of a BR beverage, would improve rowing performance during ergometer repetitions. In a randomized crossover design, 14 well-trained junior male rowers consumed 500 ml of either BR or placebo (PL) daily for 6 d. After supplementation, rowers completed 6 maximal 500-m ergometer repetitions and times were recorded. A 7-d washout period separated the 2 trials. Blood pressure, oxygen saturation, maximum heart rate, urine (specific gravity, pH, and nitrites), and lactates were collected for analysis at baseline and pre- and postperformance. Changes in the mean with 95% confidence limits were calculated. There was a likely benefit to average repetition time in the BR condition, compared with PL (0.4%, 95% confidence limits, ± 1.0%). In particular, Repetitions 4–6 showed an almost certain benefit in rowing time on BR (1.7%, 95% CL, ± 1.0%). The underlying mechanism for the observed results remains unknown, as differences observed in rowers’ physiological measures between the 2 conditions were unclear. Conclusively, nitrate supplementation in the form of BR juice resulted in improved maximal rowing-ergometer repetitions, particularly in the later stages of exercise.
Hee-Tae Roh, Su-Youn Cho, Hyung-Gi Yoon and Wi-Young So
We investigated the effects of aerobic exercise intensity on oxidative–nitrosative stress, neurotrophic factor expression, and blood–brain barrier (BBB) permeability. Fifteen healthy men performed treadmill running under low-intensity (LI), moderate-intensity (MI), and high-intensity (HI) conditions. Blood samples were collected immediately before exercise (IBE), immediately after exercise (IAE), and 60 min after exercise (60MAE) to examine oxidative–nitrosative stress (reactive oxygen species [ROS]; nitric oxide [NO]), neurotrophic factors (brain-derived neurotrophic factor [BDNF]; nerve growth factor [NGF]), and blood-brain barrier (BBB) permeability (S-100β; neuron-specific enolase). ROS concentration significantly increased IAE and following HI (4.9 ± 1.7 mM) compared with that after LI (2.8 ± 1.4 mM) exercise (p < .05). At 60MAE, ROS concentration was higher following HI (2.5 ± 1.2 mM) than after LI (1.5 ± 0.5 mM) and MI (1.4 ± 0.3 mM) conditions (p < .05). Plasma NO IAE increased significantly after MI and HI exercise (p < .05). Serum BDNF, NGF, and S-100b levels were significantly higher IAE following MI and HI exercise (p < .05). BDNF and S-100b were higher IAE following MI (29.6 ± 3.4 ng/mL and 87.1 ± 22.8 ng/L, respectively) and HI (31.4 ± 3.8 ng/mL and 100.6 ± 21.2 ng/L, respectively) than following LI (26.5 ± 3.0 ng/mL and 64.8 ± 19.2 ng/L, respectively) exercise (p < .05). 60MAE, S-100b was higher following HI (71.1 ± 14.5 ng/L) than LI (56.2 ± 14.7 ng/L) exercise (p < .05). NSE levels were not significantly different among all intensity conditions and time points (p > .05). Moderate- and/or high-intensity exercise may induce higher oxidative-nitrosative stress than may low-intensity exercise, which can increase peripheral neurotrophic factor levels by increasing BBB permeability.
Seiji Maeda, Asako Zempo-Miyaki, Hiroyuki Sasai, Takehiko Tsujimoto, Rina So and Kiyoji Tanaka
Obesity and increased arterial stiffness are independent risk factors for cardiovascular disease. Arterial stiffness is increased in obese individuals than in age-matched nonobese individuals. We demonstrated that dietary modification and exercise training are effective in reducing arterial stiffness in obese persons. However, the differences in the effect on arterial stiffness between dietary modification and exercise training are unknown. The purpose of the current study was to compare the effect of dietary modification and aerobic exercise training on arterial stiffness and endothelial function in overweight and obese persons. Forty-five overweight and obese men (48 ± 1 year) completed either a dietary modification (well-balanced nutrient, 1680 kcal/day) or an exercise-training program (walking, 40–60 min/day, 3 days/week) for 12 weeks. Before and after the intervention, all participants underwent anthropometric measurements. Arterial stiffness was measured based on carotid arterial compliance, brachial-ankle pulse wave velocity (baPWV), and endothelial function was determined by circulating level of endothelin-1 (ET-1) and nitric oxide metabolite (nitrites/nitrate as metabolite: NOx). Body mass and waist circumference significantly decreased after both intervention programs. Weight loss was greater after dietary modification than after exercise training (-10.1 ± 0.6 kg vs. -3.6 ± 0.5 kg, p < .01). Although arterial stiffness and the plasma levels of ET-1 and NOx were improved after dietary modification or exercise training, there were no differences in those improvements between the 2 types of interventions. Exercise training improves arterial function in obese men without as much weight loss as after dietary modification.
Ernest G. Rimer, Linda R. Peterson, Andrew R. Coggan and James C. Martin
Muscle-shortening velocity and hence power have been shown to increase in the presence of nitric oxide (NO). NO availability increases after consuming nitrate (NO3 -). Ingestion of NO3 -rich beetroot juice (BRJ) has increased muscle power in untrained adults.
This study determined whether NO3 - supplementation could acutely enhance maximal power in trained athletes.
In this double-blind, crossover study, 13 trained athletes performed maximal inertial-load cycling trials (3–4 s) immediately before (PRE) and after (POST) consuming either NO3 -rich (NO3) or NO3 -depleted (PLA) BRJ to assess acute changes (ie, within the same day) in maximal power (PMAX) and optimal pedaling rate (RPMopt). Participants also performed maximal isokinetic cycling (30 s) to assess performance differences after supplementation.
2 x 2 repeated-measures ANOVA indicated a greater increase in PMAX from PRE to POST NO3 (PRE 1160 ± 301 W to POST 1229 ± 317 W) than with PLA (PRE 1191 ± 298 W to POST 1213 ± 300 W) (P = .009; η p 2 = 0.45). A paired t-test verified a greater relative change in PMAX after NO3 (6.0% ± 2.6%) than with PLA (2.0% ± 3.8%) (P = .014; d = 1.21). RPMopt remained unchanged from PRE (123 ± 14 rpm) to POST PLA (122 ± 14 rpm) but increased from PRE (120 ± 14 rpm) to POST NO3 (127 ± 13 rpm) (P = .043; η p 2 = 0.30). There was no relative change in RPMopt after PLA (–0.3% ± 4.1%), but there was an increase after NO3 (6.5% ± 11.4%) (P = .049; d = 0.79). No differences were observed between the 30-s isokinetic trials.
Acute NO3 - supplementation can enhance maximal muscle power in trained athletes. These findings may particularly benefit power-sport athletes who perform brief explosive actions.
Alexei Wong, Marcos A. Sanchez-Gonzalez, Won-Mok Son, Yi-Sub Kwak and Song-Young Park
nitric oxide (NO) production, total nitrite/nitrate concentration was assayed using a commercially available Griess assay kit from Cayman Chemical (Ann Arbor, MI). The amount of nitrite/nitrate produced in the reaction mixture was determined spectrophotometrically at 540 nm (OD540) using a microplate