The Effect of Dietary Nitrate Supplementation on Agility, Linear Sprint and Vertical Jump Performance

Dietary nitrate (NO3-) supplementation has been shown to speed reaction time and enhance linear sprint speed and power production in an unfatigued state. It may therefore be suggested that NO3- supplementation could be ergogenic during all-out sprint running and reactive agility tasks, as well as during explosive forms of exercise such as vertical jumping. NO3- supplementation may also attenuate the decline in such exercise performance following fatiguing exercise. The purpose of this thesis was firstly to determine the reliability of selected exercise tests for measuring running reactive agility (reactive agility test), planned agility (change of direction t-test), 15 m linear sprint and countermovement jump performance, and then to investigate the effect of NO3- supplementation on these parameters of team sports performance in an unfatigued state and following fatiguing exercise that mimics the high-intensity intermittent demands of team sport game-play. Chapter 3: Examined the reliability of selected exercise protocols for reactive agility, change of direction, sprint and vertical jump performance. The lowest coefficient of variation (COV) and highest intraclass correlation coefficient (ICC) was observed when the fastest 15 m linear sprint out of 5 attempts (COV: 1.0%; ICC: 0.98), and the highest countermovement jump out of 3 attempts (COV: 4.6%; ICC: 0.94) were assessed independently and when the mean of all 6 reactive agility (COV: 2.0%; ICC: 0.96) and all 3 change of direction t-test (COV: 2.9%; ICC: 0.87) attempts were assessed. This information was used to inform statistical analyses within chapter 4. Results from chapter 3 provided confidence in the use of the selected exercise protocols in an intervention study due to the low day-to-day variability in performance. Chapter 4: Five days of NO3- supplementation did not improve reactive agility (NIT: 2.64 ± 0.21 s vs PLA: 2.65 ± 0.17 s, P > 0.05), change of direction t-test (NIT: 7.12 ± 0.71 s vs PLA: 7.10 ± 0.76, P > 0.05), 15 m sprint (NIT: 3.204 ± 0.212 s vs. PLA: 3.215 ± 0.206 s, P > 0.05) or countermovement jump (NIT: 36.38 ± 6.58 cm vs PLA: 37.02 ± 6.83 cm, P > 0.05) performance in an unfatigued state. In a fatigued state, 15 m sprint (NIT: 3.27 ± 0.25 s vs PLA: 3.27 ± 0.25, P > 0.05) and countermovement jump (NIT: 36.7 ± 7.2 cm vs PLA: 36.5 ± 7.0 cm, P > 0.05) performance were also unaltered following NO3- supplementation. Performance declined in a fatigued compared to unfatigued state for 15 m sprint performance (P 0.05). NO3- supplementation did not attenuate the decline in fatigued 15 m sprint performance (P > 0.05). These findings suggest that NO3- supplementation does not alter agility, linear sprint or vertical jump performance. Overall, these findings provide an important contribution to the literature regarding the limits of the ergogenic effect of NO3- supplementation for particular determinants of team sports performance, specifically in male team sports players at a dose of 8 mmol · day-1 for 5 days

Lowering of blood pressure after nitrate-rich vegetable consumption is abolished with the co-ingestion of thiocyanate-rich vegetables in healthy normotensive males

A diet rich in vegetables is known to provide cardioprotection. However, it is unclear how the consumption of different vegetables might interact to influence vascular health. This study tested the hypothesis that nitrate-rich vegetable consumption would lower systolic blood pressure but that this effect would be abolished when nitrate-rich and thiocyanate-rich vegetables are co-ingested. On four separate occasions, and in a randomised cross-over design, eleven healthy males reported to the laboratory and consumed a 750 mL vegetable smoothie that was either: low in nitrate (~ 0.3 mmol) and thiocyanate (~ 5 μmol), low in nitrate and high in SCN- (~ 72 μmol), high in nitrate (~ 4 mmol) and low in SCN- and high in nitrate and SCN-. Blood pressure as well as plasma and salivary [thiocyanate], [nitrate] and [nitrite] were assessed before and 3 hours after smoothie consumption. Plasma [nitrate] and [nitrite] and salivary [nitrate] were not different after consuming the two high-nitrate smoothies, but salivary [nitrite] was higher after consuming the high-nitrate low-thiocyanate smoothie (1183 ± 625 µM) compared to the high-nitrate high-thiocyanate smoothie (941 ± 532 µM; P<0.001). Systolic blood pressure was only lowered after consuming the high-nitrate low-thiocyanate smoothie (-3 ± 5 mmHg; P<0.05). The acute consumption of vegetables high in nitrate and low in thiocyanate lowered systolic blood pressure. However, when the same dose of nitrate-rich vegetables was co-ingested with thiocyanate-rich vegetables the increase in salivary [nitrite] was smaller and systolic blood pressure was not lowered. These findings might have implications for optimising dietary guidelines aimed at improving cardiovascular health

The effect of short-term excessive dietary fat intake on subcutaneous white adipose tissue nuclear factor-κB inflammatory signalling

The effect of short-term excessive dietary fat intake on subcutaneous white adipose tissue nuclear factor-κB inflammatory signallin

The effect of quantity and quality of dietary fat intake on subcutaneous white adipose tissue inflammatory responses

The global prevalence of obesity and obesity-associated cardiometabolic diseases is a significant public health burden. Chronic low-grade inflammation in metabolic tissues such as white adipose tissue (WAT) is linked to obesity and may play a role in disease progression. The overconsumption of dietary fat has been suggested to modulate the WAT inflammatory environment. It is also recognised that fats varying in degree of fatty acid (FA) saturation may elicit differential WAT inflammatory responses. This information has originated predominantly from animal or cell models and translation into humans in vivo remains limited. This review will summarise human intervention studies investigating the effect of dietary fat quantity and quality on subcutaneous WAT inflammation, with a specific focus on the toll like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) and nucleotide-binding and oligomerisation domain-like receptor, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome molecular signalling pathways. Overall, firm conclusions are hard to draw regarding the effect of dietary fat quantity and quality on WAT inflammatory responses due to the heterogeneity of study designs, composition of the diets and participant cohorts recruited. Previous studies have predominantly focused on measures of WAT gene expression. It is suggested that future work includes measures of WAT total content and phosphorylation of proteins involved in TLR4/NF-κB and NLRP3 signalling as this is more representative of alterations in WAT physiological function. Understanding pathways linking intake of total fat and specific FAs with WAT metabolic-inflammatory responses may have important implications for public health by informing dietary guidelines aimed at cardiometabolic risk reduction<br

Impact of high-fat overfeeding on white adipose tissue and systemic metabolic and inflammatory responses [Abstract]

No description supplie

Short-term high-fat overfeeding does not induce NF-κB inflammatory signaling in subcutaneous white adipose tissue

Context It is unclear how white adipose tissue (WAT) inflammatory signaling proteins respond during the early stages of overnutrition. Objective To investigate the effect of short-term, high-fat overfeeding on fasting abdominal subcutaneous WAT total content and phosphorylation of proteins involved in nuclear factor-κB (NF-κB) inflammatory signaling, systemic metabolic measures and inflammatory biomarkers. Design Individuals consumed a high-fat (65% total energy total fat), high-energy (50% above estimated energy requirements) diet for 7 days. Results Fifteen participants (age 27 ± 1 y; BMI 24.4 ± 0.6 kg/m2) completed the study. Body mass increased following high-fat overfeeding (+1.2 ± 0.2 kg; P Conclusion Acute lipid oversupply did not impact on total content or phosphorylation of proteins involved in WAT NF-κB inflammatory signaling, despite modest weight gain and metabolic alterations. Systemic LBP, which is implicated in the progression of low-grade inflammation during the development of obesity, increased in response to a 7-day high-fat overfeeding period.</div