Acute Sodium Ingestion Before Exercise Increases Voluntary Water Consumption Resulting in Preexercise Hyperhydration and Improvement in Exercise Performance in the Heat

2015 ◽  
Vol 25 (5) ◽  
pp. 456-462 ◽  
Author(s):  
David M. Morris ◽  
Joshua R. Huot ◽  
Adam M. Jetton ◽  
Scott R. Collier ◽  
Alan C. Utter
Keyword(s):  
Water Consumption ◽  
Exercise Performance ◽  
Time Trial ◽  
Favorable Effect ◽  
Hydration Status ◽  
Performance Time ◽  
Sodium Ingestion ◽  
Improve Exercise Performance ◽  
And Performance ◽  
Sodium Consumption

Dehydration has been shown to hinder performance of sustained exercise in the heat. Consuming fluids before exercise can result in hyperhydration, delay the onset of dehydration during exercise and improve exercise performance. However, humans normally drink only in response to thirst, which does not result in hyperhydration. Thirst and voluntary fluid consumption have been shown to increase following oral ingestion or infusion of sodium into the bloodstream. We measured the effects of acute sodium ingestion on voluntary water consumption and retention during a 2-hr hydration period before exercise. Subjects then performed a 60-min submaximal dehydration ride (DR) followed immediately by a 200 kJ performance time trial (PTT) in a warm (30 °C) environment. Water consumption and retention during the hydration period was greater following sodium ingestion (1380 ± 580 mL consumed, 821 ± 367 ml retained) compared with placebo (815 ± 483 ml consumed, 244 ± 402 mL retained) and no treatment (782 ± 454 ml consumed, 148 ± 289 mL retained). Dehydration levels following the DR were significantly less after sodium ingestion (0.7 ± 0.6%) compared with placebo (1.3 ± 0.7%) and no treatment (1.6 ± 0.4%). Time to complete the PTT was significantly less following sodium consumption (773 ± 158 s) compared with placebo (851 ± 156 s) and no treatment (872 ± 190 s). These results suggest that voluntary hyperhydration can be induced by acute consumption of sodium and has a favorable effect on hydration status and performance during subsequent exercise in the heat.

scholarly journals Effects of an Exogenous Ketone Supplement on Five‐Kilometer Running Performance

2020 ◽  
Vol 72 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Philip J. Prins ◽  
Andrew P. Koutnik ◽  
Dominic P. D’Agostino ◽  
Christopher Q. Rogers ◽  
Jacob F. Seibert ◽  
...  
Keyword(s):  
Exercise Performance ◽  
Repeated Measures ◽  
Medium Chain Triglyceride ◽  
Time Trial ◽  
Double Blind ◽  
Performance Time ◽  
Feeling Scale ◽  
Significant Difference ◽  
Improve Exercise Performance ◽  
Endurance Runners

AbstractNumerous oral ketone supplements are marketed with the claim that they will rapidly induce ketosis and improve exercise performance. The purpose of this study was to assess exercise performance time and related physiological, metabolic and perceptual responses of recreational endurance runners after ingestion of a commercially available oral ketone supplement. Recreational endurance runners (n = 10; age: 20.8 ± 1.0 years; body mass: 68.9 ± 5.6 kg; height: 175.6 ± 4.9 cm) participated in a double-blind, crossover, repeated-measures study where they were randomized to 300 mg.kg-1 body weight of an oral β-hydroxybutyrate-salt + Medium Chain Triglyceride (βHB-salt+MCT) ketone supplement or a flavor matched placebo (PLA) 60 min prior to performing a 5-km running time trial (5KTT) on a treadmill. Time, HR, RPE, affect, RER, VO2, VCO2, and VE were measured during the 5-km run. The Session RPE and affect (Feeling Scale) were obtained post-5KTT. Plasma glucose, lactate and ketones were measured at baseline, 60-min post-supplement, and immediately post-5KTT. Plasma R-βHB (endogenous isomer) was elevated from baseline and throughout the entire protocol under the βHB-salt+MCT condition (p < 0.05). No significant difference (58.3 ± 100.40 s; 95% CI: -130.12 – 13.52; p = 0.100) was observed between the βHB-salt+MCT supplement (1430.0 ± 187.7 s) and the PLA (1488.3 ± 243.8 s) in time to complete the 5KTT. No other differences (p > 0.05) were noted in any of the other physiological, metabolic or perceptual measures.

scholarly journals The Effect of Dietary Nitrate Supplementation on Physiology and Performance in Trained Cyclists

2017 ◽  
Vol 12 (5) ◽  
pp. 684-689 ◽  
Author(s):  
Joseph A. McQuillan ◽  
Deborah K. Dulson ◽  
Paul B. Laursen ◽  
Andrew E. Kilding
Keyword(s):  
Time Trial ◽  
Crossover Design ◽  
Moderate Intensity ◽  
Beetroot Juice ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Performance Time ◽  
Exercise Economy ◽  
Nitrate Supplementation ◽  
And Performance

Purpose:To determine the effect of dietary nitrate (NO3 –) supplementation on physiology and performance in well-trained cyclists after 6–8 d of NO3 – supplementation.Methods:Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg–1 · min–1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3 – (NIT) or a NO3 –-depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).Results:Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (–1.0% ± 3.0%) and exercise economy on d 7 (–1.0% ± 1.6%). However, effects for TT performance time (–0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.Conclusions:Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3 – supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.

scholarly journals Body-Cooling Paradigm in Sport: Maximizing Safety and Performance During Competition

2016 ◽  
Vol 25 (4) ◽  
pp. 382-394 ◽  
Author(s):  
William M. Adams ◽  
Yuri Hosokawa ◽  
Douglas J. Casa
Keyword(s):  
Exercise Performance ◽  
Literature Search ◽  
Evidence Synthesis ◽  
Scientific Evidence ◽  
Sport Performance ◽  
The Body ◽  
Sport Competition ◽  
Improve Exercise Performance ◽  
Body Cooling ◽  
And Performance

Context:Although body cooling has both performance and safety benefits, knowledge on optimizing cooling during specific sport competition is limited.Objectives:To identify when, during sport competition, it is optimal for body cooling and to identify optimal body-cooling modalities to enhance safety and maximize sport performance.Evidence Acquisition:A comprehensive literature search was conducted to identify articles with specific context regarding body cooling, sport performance, and cooling modalities used during sport competition. A search of scientific peer-reviewed literature examining the effects of body cooling on exercise performance was done to examine the influence of body cooling on exercise performance. Subsequently, a literature search was done to identify effective cooling modalities that have been shown to improve exercise performance.Evidence Synthesis:The cooling modalities that are most effective in cooling the body during sport competition depend on the sport, timing of cooling, and feasibility based on the constraints of the sports rules and regulations. Factoring in the length of breaks (halftime substitutions, etc), the equipment worn during competition, and the cooling modalities that offer the greatest potential to cool must be considered in each individual sport.Conclusions:Scientific evidence supports using body cooling as a method of improving performance during sport competition. Developing a strategy to use cooling modalities that are scientifically evidence-based to improve performance while maximizing athlete’s safety warrants further investigation.

scholarly journals Dose Response of a Novel Exogenous Ketone Supplement on Physiological, Perceptual, and Performance Parameters

2020 ◽  
Author(s):  
Philip Prins ◽  
Dominic P. D’Agostino ◽  
Christopher Q. Rogers ◽  
Dana L. Ault ◽  
Gary L. Welton ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cognitive Performance ◽  
Blood Lactate ◽  
Exercise Performance ◽  
Ketone Bodies ◽  
Time Trial ◽  
Gaseous Exchange ◽  
Double Blind ◽  
Post Exercise ◽  
And Performance

Abstract Background: Interest into the health, disease, and performance impact of exogenous ketone bodies has rapidly expanded due to their multifaceted physiological and signaling properties but limiting our understanding is the isolated analyses of individual types and dose/dosing protocols. Methods: Thirteen recreational male distance runners (24.8±9.6y, 72.5±8.3kg, VO2max 60.1±5.4ml/kg/min) participated in this randomized, double-blind, crossover design study. The first two sessions consisted of a 5-km running time trial (TT) familiarization and a VO2max test. During subsequent trials, subjects were randomly assigned to one (KS1:22.1g) or two (KS2:44.2g) doses of beta-hydroxybutyrate (βHB) and medium chain triglycerides (MCTs) or flavor matched placebo (PLA). Blood R-βHB, glucose, and lactate concentrations were measured at baseline (0-min), post-supplement (30 & 60mins), post-exercise (+0min, +15mins). Time, HR, RPE, affect, RER, VO2, VCO2, and VE were measured during exercise. Cognitive performance was evaluated prior to and post-exercise. Results: KS significantly increased R-βHB, with more potent and prolonged elevations in KS2, illustrating an administrative and dosing effect. R-βHB was significantly decreased in KS1 compared to KS2 illustrating a dosing and exercise interaction effect. Blood glucose elevated post-exercise but was unchanged across groups. Blood lactate significantly increased post-exercise but was augmented by KS administration. Gaseous exchange, respiration, heart rate, affect, RPE, and exercise performance was unaltered with KS administration. However, clear responders and none-responders were indicated. KS2 significantly augmented cognitive function in pre-exercise conditions, while exercise increased cognitive performance for KS1 and PLA to pre-exercise KS2 levels. Conclusion: Novel βHB+MCT formulation had a dosing effect on R-βHB and cognitive performance, an administrative response on blood lactate, while not influencing gaseous exchange, respiration, heart rate, affect, RPE, and exercise performance.

The taste of salt in the athlete’s soup: a short update with practical recommendations

2017 ◽  
Vol 65 (1) ◽  
Keyword(s):  
Exercise Performance ◽  
Sodium Intake ◽  
Taste Preference ◽  
Sodium Concentration ◽  
Fluid Replacement ◽  
Hydration Status ◽  
Plasma Volume Expansion ◽  
Increased Risk ◽  
Sodium Ingestion ◽  
The Right

The general recommendation for daily sodium consumption is about 6 g/d, as a higher intake was associated with an increased risk for cardiovascular mortality in individuals already suffering from hypertension. However, this recommendation is not necessarily valid for athletes as they often experience high sweat and sodium losses during exercise. While it is well-known that a balanced hydration status and fluid replacement are important factors to maintain an adequate exercise performance, the importance of salt losses during exercise seems to be often underestimated. This short update will focus on the role and impact of salt or sodium ingestion before, during and after exercise and its implication on performance. Pre-exercise ingestion of highly concentrated sodium solutions (164 mmol/l) induces a plasma volume expansion leading to a performance enhancing effect. Sodium intake during exercise of more than 60 min helps to prevent from or compensate dehydration. Sports drinks ingested during exercise commonly contain a sodium concentration of 30-50 mmol/l, whereas a higher concentration might be advantageous for so called salty sweaters or athletes prone to heat cramps. For a fast rehydration after exercise, drinks with a sodium concentration of around 100 mmol/l were found to be most effective. In any case, taste preference and gastrointestinal discomfort have to be considered individually and the amount of salt or sodium to be ingested in the different exercise settings depends highly on the desired goal. Finally, the timing of salt or sodium intake as well as the right dosage are of high importance to successfully influence exercise performance.

scholarly journals Does Flavonoid Consumption Improve Exercise Performance? Is It Related to Changes in the Immune System and Inflammatory Biomarkers? A Systematic Review of Clinical Studies since 2005

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1132
Author(s):  
Patricia Ruiz-Iglesias ◽  
Abril Gorgori-González ◽  
Malén Massot-Cladera ◽  
Margarida Castell ◽  
Francisco J. Pérez-Cano
Keyword(s):  
Systematic Review ◽  
Immune System ◽  
Exercise Performance ◽  
Human Subjects ◽  
Optimal Dosage ◽  
Eligibility Criteria ◽  
Beneficial Effects ◽  
Improve Exercise Performance ◽  
And Performance ◽  
Shed Light

Flavonoids are attracting increasing attention due to their antioxidant, cardioprotective, and immunomodulatory properties. Nevertheless, little is known about their role in exercise performance in association with immune function. This systematic review firstly aimed to shed light on the ergogenic potential of flavonoids. A search strategy was run using SCOPUS database. The returned studies were screened by prespecified eligibility criteria, including intervention lasting at least one week and performance objectively quantified, among others. Fifty-one studies (54 articles) met the inclusion criteria, involving 1288 human subjects, either physically untrained or trained. Secondly, we aimed to associate these studies with the immune system status. Seventeen of the selected studies (18 articles) assessed changes in the immune system. The overall percentage of studies reporting an improved exercise performance following flavonoid supplementation was 37%, the proportion being 25% when considering quercetin, 28% for flavanol-enriched extracts, and 54% for anthocyanins-enriched extracts. From the studies reporting an enhanced performance, only two, using anthocyanin supplements, focused on the immune system and found certain anti-inflammatory effects of these flavonoids. These results suggest that flavonoids, especially anthocyanins, may exert beneficial effects for athletes’ performances, although further studies are encouraged to establish the optimal dosage and to clarify their impact on immune status.

scholarly journals Reproducibility of cardiorespiratory and performance responses to exercise in hypoxia

2016 ◽  
Author(s):  
Ben J Lee ◽  
Charles D Thake
Keyword(s):  
Performance Measures ◽  
Correlation Coefficients ◽  
Time Trial ◽  
Time Of Day ◽  
Intra Class Correlation ◽  
Future Studies ◽  
Performance Time ◽  
Hypoxic Conditions ◽  
And Performance ◽  
Hypoxic Exercise

Background. Knowledge of the variance in physiological performance measures between repeated trials can inform whether familiarization sessions are necessary prior to intervention studies. The purpose of this study was to assess the reliability of cardiorespiratory and exercise performance measures during both steady state hypoxic exercise and a preloaded 16.1 km hypoxic time trial. Methods. Eighteen male participants (age, 22 ± 4 years; height, 1.77 ± 0.04 meters; body mass, 76.8 kg; estimated body fat and VO2peak = 3.50 ± 0.60 L.min-1) were divided into three groups. Reliability of responses (HR, SPO2 , VO2 , VCO2 , VE and respiratory exchange ratio; RER) to the HST (FIO2 0.14; 15 minutes rest, 60 minutes cycling at 50% normoxic VO2peak) was assessed across 3 repeat trials (HST 1, 2 and 3, n = 6). Reliability of the preloaded time trial (pTT; 15 min rest, 40 minutes cycling at 50% normoxic VO2peak, 16.1km time trial) was assessed across 3 repeat normoxic (N; FIO2 ≈ 0.21; n=6) and 3 repeat hypoxic (FIO2 ≈ 0.14; n = 6) trials. All exercise trials were undertaken at the same time of day, following exercise and dietary controls, 7 days apart. Results. Intra-class correlation coefficients (ICC’s) for mean and peak HR, SpO2 , VE , VO2 , VCO2 and blood lactate within each trial were improved from HST1 to HST2 (mean data: 0.99, 0.95, 0.75, 0.62, 0.70, 0.90; peak data: 0.98, 0.96, 0.64, 0.69, 0.74, 0.75) to HST2 and HST3 (ICC = 0.99, 0.97, 0.82, 0.85, 0.87 and 0.96 respectively). The reliability for time to pTT completion was improved following one trial, and the CV (test 2 vs. 3) was similar under normoxic (CV = 0.62) and hypoxic conditions (CV = 0.63). Conclusion. Cardiorespiratory responses to the HST were reproducible and the pTT performance time reliable in both normoxia and hypoxia. Since the reproducibility of the measurements in HST trials and reliability of pTT improved between the second and third trials, two familiarization visit are recommended prior to employing these protocols in future studies.

Effect of hypohydration and altitude exposure on aerobic exercise performance and acute mountain sickness

2010 ◽  
Vol 109 (6) ◽  
pp. 1792-1800 ◽  
Author(s):  
John W. Castellani ◽  
Stephen R. Muza ◽  
Samuel N. Cheuvront ◽  
Ingrid V. Sils ◽  
Charles S. Fulco ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Exercise Performance ◽  
Acute Mountain Sickness ◽  
Time Trial ◽  
Aerobic Performance ◽  
Hydration Status ◽  
Symptom Severity Score ◽  
Symptom Prevalence ◽  
Mountain Sickness ◽  
Experimental Trials

Hypoxia often causes body water deficits (hypohydration, HYPO); however, the effects of HYPO on aerobic exercise performance and prevalence of acute mountain sickness (AMS) at high altitude (ALT) have not been reported. We hypothesized that 1) HYPO and ALT would each degrade aerobic performance relative to sea level (SL)-euhydrated (EUH) conditions, and combining HYPO and ALT would further degrade performance more than one stressor alone; and 2) HYPO would increase the prevalence and severity of AMS symptoms. Seven lowlander men (25 ± 7 yr old; 82 ± 11 kg; mean ± SD) completed four separate experimental trials. Trials were 1) SL-EUH, 2) SL-HYPO, 3) ALT-EUH, and 4) ALT-HYPO. In HYPO, subjects were dehydrated by 4% of body mass. Subjects maintained hydration status overnight and the following morning entered a hypobaric chamber (at SL or 3,048 m, 27°C) where they completed 30 min of submaximal exercise immediately followed by a 30-min performance time trial (TT). AMS was measured with the Environmental Symptoms Questionnaire-Cerebral Score (AMS-C) and the Lake Louise Scoring System (LLS). The percent change in TT performance, relative to SL-EUH, was −19 ± 12% (334 ± 64 to 278 ± 87 kJ), −11 ± 10% (334 ± 64 to 293 ± 33 kJ), and −34 ± 22% (334 ± 64 to 227 ± 95 kJ), for SL-HYPO, ALT-EUH, and ALT-HYPO, respectively. AMS symptom prevalence was 2/7 subjects at ALT-EUH for AMS-C and LLS and 5/7 and 4/7 at ALT-HYPO for AMS-C and LLS, respectively. The AMS-C symptom severity score (AMS-C score) tended to increase from ALT-EUH to ALT-HYPO but was not significant ( P = 0.07). In conclusion, hypohydration at 3,048 m 1) degrades aerobic performance in an additive manner with that induced by ALT; and 2) did not appear to increase the prevalence/severity of AMS symptoms.

scholarly journals Pedal force asymmetries and performance during a 20-km cycling time trial

Kinesiology ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Rodrigo R. Bini ◽  
Tiago C. Jacques ◽  
Carlos H. Sperb ◽  
Fábio J. Lanferdini ◽  
Marco A. Vaz
Keyword(s):  
Effect Size ◽  
Force Production ◽  
Time Trial ◽  
Cycling Time Trial ◽  
Pedal Force ◽  
Performance Time ◽  
Competitive Cyclists ◽  
And Performance ◽  
The Relationship ◽  
Cycling Time

It is unclear if applying larger or more symmetrical pedal forces leads to better performance in cycling. The aims of this study were to assess the relationship between pedal force production and performance in a cycling time trial and to evaluate the relationship between asymmetries in pedal force production and performance. Fifteen competitive cyclists/triathletes performed a 20 km cycling time trial on a cycle trainer while bilateral forces applied to the pedals were recorded along with total time. Total forces applied to the pedals were computed and converted into dominant and non-dominant forces using a leg preference inventory. Pedal force asymmetries ranged from 43% (in favour of the dominant limb) to 34% (in favour of the non-dominant limb). The relationship between total pedal force (averaged from both pedals) and performance time was small (r=-.32, effect size=.66) as well as the association between the asymmetry indices and performance time (r=.01, effect size=.06). In conclusion, applying large forces on the pedals and balancing pedal force application between the dominant and non-dominant limbs did not lead to better performance in this cycling time trial.

scholarly journals Dose Response of a Novel Exogenous Ketone Supplement on Physiological, Perceptual, and Performance Parameters

2020 ◽  
Author(s):  
Philip Prins ◽  
Dominic P. D’Agostino ◽  
Christopher Q. Rogers ◽  
Dana L. Ault ◽  
Gary L. Welton ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cognitive Performance ◽  
Blood Lactate ◽  
Exercise Performance ◽  
Ketone Bodies ◽  
Time Trial ◽  
Gaseous Exchange ◽  
Double Blind ◽  
Post Exercise ◽  
And Performance

Abstract Background: Interest into the health, disease, and performance impact of exogenous ketone bodies has rapidly expanded due to their multifaceted physiological and signaling properties but limiting our understanding is the isolated analyses of individual types and dose/dosing protocols. Methods: Thirteen recreational male distance runners (24.8±9.6y, 72.5±8.3kg, VO2max 60.1±5.4ml/kg/min) participated in this randomized, double-blind, crossover design study. The first two sessions consisted of a 5-km running time trial (TT) familiarization and a VO2max test. During subsequent trials, subjects were randomly assigned to one (KS1:22.1g) or two (KS2:44.2g) doses of beta-hydroxybutyrate (βHB) and medium chain triglycerides (MCTs) or flavor matched placebo (PLA). Blood R-βHB, glucose, and lactate concentrations were measured at baseline (0-min), post-supplement (30 & 60mins), post-exercise (+0min, +15mins). Time, HR, RPE, affect, RER, VO2, VCO2, and VE were measured during exercise. Cognitive performance was evaluated prior to and post-exercise. Results: KS significantly increased R-βHB, with more potent and prolonged elevations in KS2, illustrating an administrative and dosing effect. R-βHB was significantly decreased in KS1 compared to KS2 illustrating a dosing and exercise interaction effect. Blood glucose elevated post-exercise but was unchanged across groups. Blood lactate significantly increased post-exercise but was augmented by KS administration. Gaseous exchange, respiration, heart rate, affect, RPE, and exercise performance was unaltered with KS administration. However, clear responders and none-responders were indicated. KS2 significantly augmented cognitive function in pre-exercise conditions, while exercise increased cognitive performance for KS1 and PLA to pre-exercise KS2 levels. Conclusion: Novel βHB+MCT formulation had a dosing effect on R-βHB and cognitive performance, an administrative response on blood lactate, while not influencing gaseous exchange, respiration, heart rate, affect, RPE, and exercise performance.

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