Effect of Sodium Bicarbonate Supplementation on 2000-m Rowing Performance

2014 ◽  
Vol 9 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Ruth M. Hobson ◽  
Roger C. Harris ◽  
Dan Martin ◽  
Perry Smith ◽  
Ben Macklin ◽  
...  

The ability to buffer H+ could be vital to exercise performance, as high concentrations of H+ contribute to the development of fatigue.Purpose:The authors examined the effect of sodium bicarbonate (SB) supplementation on 2000-m rowing-ergometer performance.Methods:Twenty male rowers (age 23 ± 4 y, height 1.85 ± 0.08 m, mass 82.5 ± 8.9 kg, 2000-m personal-best time 409 ± 16 s) completed two 2000-m rowing-ergometer time trials, separated by 48 h. Participants were supplemented before exercise with 0.3 g/kg body mass of SB or a placebo (maltodextrin; PLA). The trials were conducted using a double-blinded, randomized, counterbalanced crossover study design. Time to complete the 2000-m and time taken for each 500-m split were recorded. Blood lactate, bicarbonate, pH, and base excess were determined preexercise, immediately postexercise, and 5 min postexercise. Performance data were analyzed using paired t tests, as well as magnitude-based inferences; hematological data were analyzed using a repeated-measures ANOVA.Results:Using paired t tests, there was no benefit of SB over PLA (P = .095). However, using magnitude-based inferences there was a likely beneficial effect of SB compared with PLA (PLA 412.0 ± 15.1 s, SB 410.7 ± 14.9 s). Furthermore, SB was 0.5 ± 1.2 s faster than PLA in the third 500 m (P = .035; possibly beneficial) and 1.1 ± 1.7 s faster in the fourth 500 m (P = .004; very likely beneficial). All hematological data were different between SB and PLA and were different from preexercise to postexercise.Conclusion:SB supplementation is likely to be beneficial to the performance of those competing in 2000-m rowing events, particularly in the second half of the event.

2012 ◽  
Vol 7 (2) ◽  
pp. 152-160 ◽  
Author(s):  
Amelia J. Carr ◽  
Gary J. Slater ◽  
Christopher J. Gore ◽  
Brian Dawson ◽  
Louise M. Burke

Purpose:The aim of this study was to determine the effect and reliability of acute and chronic sodium bicarbonate ingestion for 2000-m rowing ergometer performance (watts) and blood bicarbonate concentration [HCO3−].Methods:In a crossover study, 7 well-trained rowers performed paired 2000-m rowing ergometer trials under 3 double-blinded conditions: (1) 0.3 grams per kilogram of body mass (g/kg BM) acute bicarbonate; (2) 0.5 g/kg BM daily chronic bicarbonate for 3 d; and (3) calcium carbonate placebo, in semi-counterbalanced order. For 2000-m performance and [HCO3−], we examined differences in effects between conditions via pairwise comparisons, with differences interpreted in relation to the likelihood of exceeding smallest worthwhile change thresholds for each variable. We also calculated the within-subject variation (percent typical error).Results:There were only trivial differences in 2000-m performance between placebo (277 ± 60 W), acute bicarbonate (280 ± 65 W) and chronic bicarbonate (282 ± 65 W); however, [HCO3−] was substantially greater after acute bicarbonate, than with chronic loading and placebo. Typical error for 2000-m mean power was 2.1% (90% confidence interval 1.4 to 4.0%) for acute bicarbonate, 3.6% (2.5 to 7.0%) for chronic bicarbonate, and 1.6% (1.1 to 3.0%) for placebo. Postsupplementation [HCO3−] typical error was 7.3% (5.0 to 14.5%) for acute bicarbonate, 2.9% (2.0 to 5.7%) for chronic bicarbonate and 6.0% (1.4 to 11.9%) for placebo.Conclusion:Performance in 2000-m rowing ergometer trials may not substantially improve after acute or chronic bicarbonate loading. However, performances will be reliable with both acute and chronic bicarbonate loading protocols.


2012 ◽  
Vol 7 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Peter D. Kupcis ◽  
Gary J. Slater ◽  
Cathryn L. Pruscino ◽  
Justin G. Kemp

Purpose:The effect of sodium bicarbonate (NaHCO3) ingestion on prerace hydration status and on 2000 m ergometer performance in elite lightweight rowers was examined using a randomized, cross-over, double-blinded design.Methods:To simulate body mass (BM) management strategies common to lightweight rowing, oarsmen reduced BM by approx. 4% in the 24 h preceding the trials, and, in the 2 h before performance, undertook nutritional recovery consisting of mean 43.2 kJ/kg, 2.2 g of CHO per kilogram, 31.8 mg of Na+per kilogram, 24.3 mL of H2O per kilogram, and NaHCO3(0.3 g of NaHCO3per kilogram BM) or placebo (PL; 0.15 g of corn flour per kilogram BM) at 70 to 90 min before racing.Results:At 25 min before performance, NaHCO3had increased blood pH (7.48 ± 0.02 vs PL: 7.41 ± 0.03,P= .005) and bicarbonate concentrations (29.1 ± 1.8 vs PL: 23.9 ± 1.6 mmol/L,P< .001), whereas BM, urine specific gravity, and plasma volume changes were similar between trials. Rowing ergometer times were similar between trials (NaHCO3: 397.8 ± 12.6; PL: 398.6 ± 13.8 s,P= .417), whereas posttest bicarbonate (11.6 ± 2.3 vs 9.4 ± 1.8 mmol/L,P= .003) and lactate concentration increases (13.4 ± 1.7 vs 11.9 ± 1.9 mmol/L,P= .001) were greater with NaHCO3.Conclusion:Sodium bicarbonate did not further enhance rehydration or performance in lightweight rowers when undertaking recommended post-weigh-in nutritional recovery strategies.


2021 ◽  
Vol 80 (1) ◽  
pp. 277-285
Author(s):  
Robert Trybulski ◽  
Jakub Jarosz ◽  
Michal Krzysztofik ◽  
Aleksandra Filip-Stachnik ◽  
Patryk Matykiewicz ◽  
...  

Abstract The goal of the present study was to evaluate the effect of contrast tempo movement on bar velocity changes during a multi-set bench press exercise. In randomized and counter-balanced order, participants performed three sets of the bench press exercise at 60%1RM under two testing conditions: E-E where all repetitions were performed with explosive (X/0/X/0) movement tempo; and S-E where the first two repetitions were performed with a slow tempo (5/0/X/0) while the third repetition was performed with explosive movement tempo (slow, slow, explosive). Twelve healthy men volunteered for the study (age = 30 ± 5 years; body mass = 88 ± 10 kg; bench press 1RM = 145 ± 24 kg). The three-way repeated measures ANOVA (tempo × set × repetition) showed statistically significant multi-interaction effect for peak bar velocity (p < 0.01; η2 = 0.23), yet not for mean bar velocity (p = 0.09; η2 = 0.14). The post hoc results for multi-interaction revealed that peak bar velocity in the 3rd repetition was significantly higher for E-E compared to SE only during set 1 (p < 0.001). Therefore, the distribution of movement tempo had a significant impact on peak bar velocity, but not on mean bar velocity. The decrease in peak bar velocity in the 3rd repetition during the S-E condition was observed only in the first set, while such a tendency was not observed in the second and third set.


Author(s):  
Hye-Jeong Park ◽  
Dhananjay Yadav ◽  
Da-Jeong Jeong ◽  
Suk-Jeong Kim ◽  
Myung-Ae Bae ◽  
...  

The current study was designed to investigate the short-term effects of policosanol consumption on blood pressure (BP) and the lipid parameters in healthy Korean participants with prehypertension. A total of 84 healthy participants were randomly allocated to three groups receiving placebo, 10 mg of policosanol, or 20 mg of policosanol for 12 weeks. Based on an average of three measurements of peripheral BP, the policosanol 20 mg group exhibited the most significant reduction, that is, up to 7.7% reduction of average systolic BP (SBP) from 136.3 ± 6.1 mmHg (week 0) to 125.9 ± 8.6 mmHg (week 12, p < 0.001). Between group comparisons using repeated measures ANOVA showed that the policosanol 20 mg group had a significant reduction of SBP at 12 weeks (p = 0.020) and a reduction of diastolic BP (DBP) at 8 weeks (p = 0.041) and 12 weeks (p = 0.035). The policosanol 10 mg and 20 mg groups showed significant reductions in aortic SBP of 7.4% and 8.3%, respectively. The policosanol groups showed significant reductions of total cholesterol (TC) of 9.6% and 8.6% and low-density lipoproteins (LDL-C) of 21% and 18% for 10 mg and 20 mg of policosanol, respectively. Between group comparisons using repeated measures ANOVA showed that the policosanol (10 mg and 20 mg) groups at 12 weeks had a significant reduction of TC (p = 0.0004 and p = 0.001) and LDL-C (p = 0.00005 and p = 0.0001) and elevation of %HDL-C (p = 0.048 and p = 0.014). In conclusion, 12-week consumption of policosanol resulted in significant reductions of peripheral SBP and DBP, aortic SBP and DBP, mean arterial pressure (MAP), and serum TC and LDL-C with elevation of % HDL-C.


2013 ◽  
Vol 23 (5) ◽  
pp. 480-487 ◽  
Author(s):  
Ruth M. Hobson ◽  
Roger C. Harris ◽  
Dan Martin ◽  
Perry Smith ◽  
Ben Macklin ◽  
...  

Purpose:To examine the effect of beta-alanine only and beta-alanine with sodium bicarbonate supplementation on 2,000-m rowing performance.Methods:Twenty well-trained rowers (age 23 ± 4 y; height 1.85 ± 0.08 m; body mass 82.5 ± 8.9 kg) were assigned to either a placebo or beta-alanine (6.4 g·d−1 for 4 weeks) group. A 2,000-m rowing time trial (TT) was performed before supplementation (Baseline) and after 28 and 30 days of supplementation. The post supplementation trials involved supplementation with either maltodextrin or sodium bicarbonate in a double-blind, crossover design, creating four study conditions (placebo with maltodextrin; placebo with sodium bicarbonate; beta-alanine with maltodextrin; beta-alanine with sodium bicarbonate). Blood lactate, pH, bicarbonate, and base excess were measured pre-TT, immediately post-TT and at TT+5 min. Performance data were analyzed using magnitude based inferences.Results:Beta-alanine supplementation was very likely to be beneficial to 2,000-m rowing performance (6.4 ± 8.1 s effect compared with placebo), with the effect of sodium bicarbonate having a likely benefit (3.2 ± 8.8 s). There was a small (1.1 ± 5.6 s) but possibly beneficial additional effect when combining chronic beta-alanine supplementation with acute sodium bicarbonate supplementation compared with chronic beta-alanine supplementation alone. Sodium bicarbonate ingestion led to increases in plasma pH, base excess, bicarbonate, and lactate concentrations.Conclusions:Both chronic beta-alanine and acute sodium bicarbonate supplementation alone had positive effects on 2,000-m rowing performance. The addition of acute sodium bicarbonate to chronic beta-alanine supplementation may further enhance rowing performance.


Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight

The use of latent curve models (LCMs) has increased almost exponentially during the last decade. Oftentimes, researchers regard LCM as a “new” method to analyze change with little attention paid to the fact that the technique was originally introduced as an “alternative to standard repeated measures ANOVA and first-order auto-regressive methods” (Meredith & Tisak, 1990, p. 107). In the first part of the paper, this close relationship is reviewed, and it is demonstrated how “traditional” methods, such as the repeated measures ANOVA, and MANOVA, can be formulated as LCMs. Given that latent curve modeling is essentially a large-sample technique, compared to “traditional” finite-sample approaches, the second part of the paper addresses the question to what degree the more flexible LCMs can actually replace some of the older tests by means of a Monte-Carlo simulation. In addition, a structural equation modeling alternative to Mauchly’s (1940) test of sphericity is explored. Although “traditional” methods may be expressed as special cases of more general LCMs, we found the equivalence holds only asymptotically. For practical purposes, however, no approach always outperformed the other alternatives in terms of power and type I error, so the best method to be used depends on the situation. We provide detailed recommendations of when to use which method.


2020 ◽  
Vol 1 ◽  
pp. 2485-2494
Author(s):  
S. W. Eikevåg ◽  
A. Kvam ◽  
M. K. Bjølseth ◽  
J. F. Erichsen ◽  
M. Steinert

AbstractWhen designing high performance sports equipment for Paralympic athletes, there are many unknowns for the design engineer to consider. The design challenge is an optimisation task per individual athlete. However, modelling this optimisation is difficult due to the many variables. This article presents the design of an experiment for identifying and evaluating various seating positions in Paralympic rowing by using a rowing ergometer with a modified seat. Results indicate that changing seating position has a substantial impact on per-athlete rowing performance.


2021 ◽  
pp. bjophthalmol-2020-317664
Author(s):  
Carly SY Lam ◽  
Wing Chun Tang ◽  
Paul H Lee ◽  
Han Yu Zhang ◽  
Hua Qi ◽  
...  

AimsTo determine myopia progression in children who continued to wear the defocus incorporated multiple segments (DIMS) lenses or switched from single vision (SV) to DIMS lenses for a 1-year period following a 2-year myopia control trial.Methods128 children participated in this study. The children who had worn DIMS lenses continued to wear DIMS lenses (DIMS group), and children who had worn SV lenses switched to wear DIMS lenses (Control-to-DIMS group). Cycloplegic spherical equivalent refraction (SER) and axial length (AL) were measured at 6-month interval. Historical controls were age matched to the DIMS group at 24 months and used for comparing the third-year changes.ResultsOver 3 years, SER and AL changes in the DIMS group (n=65) were −0.52±0.69D and 0.31±0.26 mm; these changes were not statistically significant over time (repeated measures analysis of variance, p>0.05).SER (−0.04±0. 38D) and AL (0.08±0.12 mm) changes in the Control-to-DIMS group (n=55) in the third year were less compared with the first (mean difference=0.45 ± 0.30D, 0.21±0.11 mm, p<0.001) and second (0.34±0.30D, 0.12±0.10 mm, p<0.001) years.Changes in SER and AL in both groups over that period were significantly less than in the historical control group (DIMS vs historical control: mean difference=−0.18±0.42D, p=0.012; 0.08±0.15 mm, p=0.001; Control-to-DIMS versus historical control: adjusted mean differences=−0.30±0.42D, p<0.001; 0.12±0.16 mm, p<0.001).ConclusionsMyopia control effect was sustained in the third year in children who had used the DIMS spectacles in the previous 2 years and was also shown in the children switching from SV to DIMS lenses.


2021 ◽  
pp. 154596832110231
Author(s):  
Kishoree Sangarapillai ◽  
Benjamin M. Norman ◽  
Quincy J. Almeida

Background. Exercise is increasingly becoming recognized as an important adjunct to medications in the clinical management of Parkinson’s disease (PD). Boxing and sensory exercise have shown immediate benefits, but whether they continue beyond program completion is unknown. This study aimed to investigate the effects of boxing and sensory training on motor symptoms of PD, and whether these benefits remain upon completion of the intervention. Methods. In this 20-week double-blinded randomized controlled trial, 40 participants with idiopathic PD were randomized into 2 treatment groups, (n = 20) boxing or (n = 20) sensory exercise. Participants completed 10 weeks of intervention. Motor symptoms were assessed at (week 0, 10, and 20) using the Unified Parkinson’s Disease Rating Scale (UPDRS-III). Data were analyzed using SPSS, and repeated-measures ANOVA was conducted. Results. A significant interaction effect between groups and time were observed F(1, 39) = 4.566, P = .036, where the sensory group improved in comparison to the boxing group. Post hoc analysis revealed that in comparison to boxing, the effects of exercise did not wear off at washout (week 20) P < .006. Conclusion. Future rehabilitation research should incorporate similar measures to explore whether effects of exercise wear off post intervention.


Author(s):  
Colton Haight ◽  
Sandra Moritz ◽  
Tanis Walch

AbstractThe relationships among the time of imagery use on performance and self-efficacy in college baseball players during a hitting task was examined. Participants (n=24) were randomly assigned to one of three imagery conditions: (a) before practice, (b) during practice, (c) after practice. A one-shot MG-M imagery intervention was used. Results from a 3 (imagery group) ×2 (pretest and posttest) repeated measures ANOVA showed only a significant time by imagery group interaction for self-efficacy (F (2, 21)=4.67, p<0.05). These findings suggest that imagery had a stronger psychological effect than physical effect.


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