A Double-Blind, Randomized, Placebo-Controlled Pilot Study examining an Oxygen Nanobubble Beverage for 16.1-km Time Trial and Repeated Sprint Cycling Performance.

There is growing interest of ergogenic aids that deliver supplemental oxygen during exercise and recovery, however, breathing supplemental oxygen via specialist facemasks is often not feasible. Therefore, this study investigated the effect of an oxygen-nanobubble beverage during submaximal and repeated sprint cycling. In a double-blind, randomized, placebo-controlled study, 10 male cyclists (peak aerobic capacity, 56.9 ± 6.1 mL·kg-1·min-1; maximal aerobic power, 385 ± 25 W) completed submaximal or maximal exercise after consuming an oxygen-nanobubble (O2) or placebo (PLA) beverage. Submaximal trials comprised 30-min of steady-state cycling at 60% peak aerobic capacity and 16.1-km time-trial (TT). Maximal trials involved 4 × 30 s Wingate tests interspersed by 4-min recovery. Time-to-completion during the 16.1-km TT was 2.4% faster after O2 compared with PLA (95% CI = 0.7-4.0%, p = 0.010, d = 0.41). Average power for the 16.1-km TT was 4.1% higher for O2 vs. PLA (95% CI = 2.1-7.3%, p = 0.006, d = 0.28). Average peak power during the repeated Wingate tests increased by 7.1% for O2 compared with PLA (p = 0.002, d = 0.58). An oxygen-nanobubble beverage improves performance during submaximal and repeated sprint cycling, therefore may provide a practical and effective ergogenic aid for competitive cyclists.

Sodium Bicarbonate and Time-to-Exhaustion Cycling Performance: A Retrospective Analysis Exploring the Mediating Role of Expectation.

BACKGROUND: Research has shown that ingesting 0.3 g·kg-1 body mass sodium bicarbonate (NaHCO3) can improve time-to-exhaustion (TTE) cycling performance, but the influence of psychophysiological mechanisms on ergogenic effects is not yet understood. OBJECTIVE: This study retrospectively examined whether changes in TTE cycling performance are mediated by positive expectations of receiving NaHCO3 and/or the decline in blood bicarbonate during exercise. METHODS: In a randomised, crossover, counterbalanced, double-blind, placebo-controlled design, 12 recreationally trained cyclists (maximal oxygen consumption, 54.4 ± 5.7 mL·kg·min-1) performed four TTE cycling tests 90 min after consuming: (1) 0.3 g·kg-1 body mass NaHCO3 in 5 mL·kg-1 body mass solution, (2) 0.03 g·kg-1 body mass sodium chloride in solution (placebo), (3) 0.3 g·kg-1 body mass NaHCO3 in capsules and (4) cornflour in capsules (placebo). Prior to exercise, participants rated on 1-5 Likert type scales how much they expected the treatment they believe had been given would improve performance. Capillary blood samples were measured for acid-base balance at baseline, pre-exercise and post-exercise. RESULTS: Administering NaHCO3 in solution and capsules improved TTE compared with their respective placebos (solution: 27.0 ± 21.9 s, p = 0.001; capsules: 23.0 ± 28.1 s, p = 0.016). Compared to capsules, NaHCO3 administered via solution resulted in a higher expectancy about the benefits on TTE cycling performance (Median: 3.5 vs. 2.5, Z = 2.135, p = 0.033). Decline in blood bicarbonate during exercise was higher for NaHCO3 given in solution compared to capsules (2.7 ± 2.1 mmol·L-1, p = 0.001). Mediation analyses showed that improvements in TTE cycling were indirectly related to expectancy and decline in blood bicarbonate when NaHCO3 was administered in solution but not capsules. CONCLUSIONS: Participants' higher expectations when NaHCO3 is administered in solution could result in them exerting themselves harder during TTE cycling, which subsequently leads to a greater decline in blood bicarbonate and larger improvements in performance. KEY POINTS: Ingesting 0.3 g·kg-1 body mass sodium bicarbonate in solution and capsules improved time-to-exhaustion cycling performance Positive expectancy about the benefits of sodium bicarbonate and decline in blood bicarbonate were higher when sodium bicarbonate was administered in solution compared with capsules Improvements in time-to-exhaustion cycling performance for sodium bicarbonate administered in solution were related to expectancy and the enhanced extracellular buffering response.

Beneficial effects of oral and topical sodium bicarbonate during a battery of team sport-specific exercise tests in recreationally trained male athletes.

OBJECTIVE: This study examined the effects of oral and topical (PR Lotion; Momentous) sodium bicarbonate (NaHCO3) during a battery of team sport-specific exercise tests. METHOD: In a block randomized, crossover, double-blind, placebo-controlled design, 14 recreationally trained male team sport athletes performed a familiarization visit and three experimental trials receiving: (i) 0.3 g·kg-1 body mass (BM) NaHCO3 in capsules + placebo lotion (SB-ORAL), (ii) placebo capsules +0.9036 g·kg-1 BM PR Lotion (SB-LOTION), or (iii) placebo capsules + placebo lotion (PLA). Supplements were given ~120 min prior to the team sport-specific exercise tests: countermovement jumps (CMJ), 8 × 25 m repeated sprints and Yo-Yo Intermittent Recovery Level 2 (Yo-Yo IR2). Blood acid-base balance (pH, bicarbonate) and electrolytes (sodium, potassium) were measured throughout. Rating of perceived exertion (RPE) was recorded after each sprint and post-Yo-Yo IR2. RESULTS: Distance covered during the Yo-Yo IR2 was 21% greater for SB-ORAL compared with PLA (+94 m; p = 0.009, d = 0.64) whereas performance was only 7% greater for SB-LOTION compared with PLA (480 ± 122 vs. 449 ± 110 m; p = 0.084). Total completion time for the 8 × 25 m repeated sprint test was 1.9% faster for SB-ORAL compared with PLA (-0.61 s; p = 0.020, d = 0.38) and 2.0% faster for SB-LOTION compared with PLA (-0.64 s; p = 0.036, d = 0.34). CMJ performance was similar between treatments (p > 0.05). Blood acid-base balance and electrolytes were significantly improved for SB-ORAL compared with PLA, but no differences were observed for SB-LOTION. Compared to PLA, RPE was lower for SB-LOTION after the fifth (p = 0.036), sixth (p = 0.012), and eighth (p = 0.040) sprints and for SB-ORAL after the sixth (p = 0.039) sprint. CONCLUSIONS: Oral NaHCO3 improved 8 × 25 m repeated sprint (~2%) and Yo-Yo IR2 performance (21%). Similar improvements in repeated sprint times were observed for topical NaHCO3 (~2%), but no significant benefits were reported for Yo-Yo IR2 distance or blood acid-base balance compared to PLA. These findings suggest that PR Lotion might not be an effective delivery system for transporting NaHCO3 molecules across the skin and into systematic circulation, therefore further research is needed to elucidate the physiological mechanisms responsible for the ergogenic effects of PR Lotion.

Efficacy of sodium bicarbonate ingestion strategies for protecting blinding.

Sodium bicarbonate (NaHCO3) is a widely researched ergogenic aid, but the optimal blinding strategy during randomised placebo-controlled trials is unknown. In this multi-study project, we aimed to determine the most efficacious ingestion strategy for blinding NaHCO3 research. During study one, 16 physically active adults tasted 0.3 g kg-1 body mass NaHCO3 or 0.03 g kg-1 body mass sodium chloride placebo treatments given in different flavour (orange, blackcurrant) and temperature (chilled, room temperature) solutions. They were required to guess which treatment they had received. During study two, 12 recreational athletes performed time-to-exhaustion (TTE) cycling trials (familiarisation, four experimental). Using a randomised, double-blind design, participants consumed 0.3 g kg-1 body mass NaHCO3 or a placebo in 5 mL kg-1 body mass chilled orange squash/water solutions or capsules and indicated what they believed they had received immediately after consumption, pre-TTE and post-TTE. In study one, NaHCO3 prepared in chilled orange squash resulted in the most unsure ratings (44%). In study two, giving NaHCO3 in capsules resulted in more unsure ratings than in solution after consumption (92 vs 33%), pre-TTE (67 vs. 17%) and post-TTE (50 vs. 17%). Administering NaHCO3 in capsules was the most efficacious blinding strategy which provides important implications for researchers conducting randomised placebo-controlled trials.

The effects of sodium bicarbonate supplementation at individual time-to-peak blood bicarbonate on 4-km cycling time trial performance in the heat.

The purpose of this study was to explore the effect of individualised sodium bicarbonate (NaHCO3) supplementation according to a pre-established individual time-to-peak (TTP) blood bicarbonate (HCO3-) on 4-km cycling time trial (TT) performance in the heat. Eleven recreationally trained male cyclists (age: 28 ± 6 years, height: 180 ± 6 cm, body mass: 80.5 ± 8.4 kg) volunteered for this study in a randomised, crossover, triple-blind, placebo-controlled design. An initial visit was conducted to determine TTP HCO3- following 0.2 g.kg-1 body mass (BM) NaHCO3 ingestion. Subsequently, on three separate occasions, participants completed a 4-km cycling TT in the heat (30 degrees centigrade; °C) (relative humidity ∼40%) following ingestion of either NaHCO3 (0.2 g.kg-1 body mass), a sodium chloride placebo (0.2 g.kg-1 BM; PLA) at the predetermined individual TTP HCO3-, or no supplementation (control; CON) . Absolute peak [HCO3-] prior to the 4-km cycling TT's was elevated for NaHCO3 compared to PLA (+2.8 mmol.l-1; p = 0.002; g = 2.2) and CON (+2.5 mmol.l-1; p < 0.001; g = 2.1). Completion time following NaHCO3 was 5.6 ± 3.2 s faster than PLA (1.6%; CI: 2.8, 8.3; p = 0.001; g = 0.2) and 4.7 ± 2.8 s faster than CON (1.3%; CI: 2.3, 7.1; p = 0.001; g = 0.2). These results demonstrate that NaHCO3 ingestion at a pre-established individual TTP HCO3- improves 4-km cycling TT performance in the heat, likely through enhancing buffering capacity.Highlights This is the first time NaHCO3 ingestion has been shown to improve 4-km cycling TT performance in conditions of high ambient heat.A smaller dose of NaHCO3 (0.2 g.kg-1 BM) is ergogenic in the heat, which is smaller than the dose typically ingested for sports performance (0.3 g.kg-1 BM). This is important, as gastrointestinal discomfort is typically lower as the dose reduces.This study suggests that the individualised time-to-peak HCO3- ingestion strategy with lower doses of NaHCO3 is an ergogenic strategy in conditions of high ambient heat.

Consumption of New Zealand Blackcurrant Extract Improves Recovery from Exercise-Induced Muscle Damage in Non-Resistance Trained Men and Women: A Double-Blind Randomised Trial.

BACKGROUND: Blackcurrant is rich in anthocyanins that may protect against exercise-induced muscle damage (EIMD) and facilitate a faster recovery of muscle function. We examined the effects of New Zealand blackcurrant (NZBC) extract on indices of muscle damage and recovery following a bout of strenuous isokinetic resistance exercise. METHODS: Using a double-blind, randomised, placebo controlled, parallel design, twenty-seven healthy participants received either a 3 g·day-1 NZBC extract (n = 14) or the placebo (PLA) (n = 13) for 8 days prior to and 4 days following 60 strenuous concentric and eccentric contractions of the biceps brachii muscle on an isokinetic dynamometer. Muscle soreness (using a visual analogue scale), maximal voluntary contraction (MVC), range of motion (ROM) and blood creatine kinase (CK) were assessed before (0 h) and after (24, 48, 72 and 96 h) exercise. RESULTS: Consumption of NZBC extract resulted in faster recovery of baseline MVC (p = 0.04), attenuated muscle soreness at 24 h (NZBC: 21 ± 10 mm vs. PLA: 40 ± 23 mm, p = 0.02) and 48 h (NZBC: 22 ± 17 vs. PLA: 44 ± 26 mm, p = 0.03) and serum CK concentration at 96 h (NZBC: 635 ± 921 UL vs. PLA: 4021 ± 4319 UL, p = 0.04) following EIMD. CONCLUSIONS: Consumption of NZBC extract prior to and following a bout of eccentric exercise attenuates muscle damage and improves functional recovery. These findings are of practical importance in recreationally active and potentially athletic populations, who may benefit from accelerated recovery following EIMD.

Effect of Warm-Up and Sodium Bicarbonate Ingestion on 4-km Cycling Time-Trial Performance.

PURPOSE: To examine whether an ecologically valid, intermittent, sprint-based warm-up strategy impacted the ergogenic capacity of individualized sodium bicarbonate (NaHCO3) ingestion on 4-km cycling time-trial (TT) performance. METHODS: A total of 8 male cyclists attended 6 laboratory visits for familiarization, determination of time to peak blood bicarbonate, and 4 × 4-km cycling TTs. Experimental beverages were administered doubleblind. Treatments were conducted in a block-randomized, crossover order: intermittent warm-up + NaHCO3 (IWSB), intermittent warm-up + placebo, control warm-up + NaHCO3 (CWSB), and control warm-up + placebo (CWP). The intermittent warm-up comprised exercise corresponding to lactate threshold (5 min at 50%, 2 min at 60%, 2 min at 80%, 1 min at 100%, and 2 min at 50%) and 3 × 10-second maximal sprints. The control warm-up comprised 16.5 minutes cycling at 150 W. Participants ingested 0.3 g·kg body mass-1 NaHCO3 or 0.03 g·kg body mass-1 sodium chloride (placebo) in 5 mL·kg body mass-1 fluid (3:2, water and sugar-free orange squash). Paired t tests were conducted for TT performance. Hematological data (blood bicarbonate and blood lactate) and gastrointestinal discomfort were analyzed using repeated-measures analysis of variance. RESULTS: Performance was faster for CWSB versus IWSB (5.0 [6.1] s; P = .052) and CWP (5.8 [6.0] s; P = .03). Pre-TT bicarbonate concentration was elevated for CWSB versus IWSB (+9.3 mmol·L-1; P < .001) and CWP (+7.1 mmol·L-1; P < .001). Post-TT blood lactate concentration was elevated for CWSB versus CWP (+2.52 mmol·L-1; P = .022). Belching was exacerbated pre-warm-up for IWSB versus intermittent warm-up +placebo (P = .046) and CWP (P = .027). CONCLUSION: An intermittent, sprint-based warm-up mitigated the ergogenic benefits of NaHCO3 ingestion on 4-km cycling TT performance.

Effects of post-exercise sodium bicarbonate ingestion on acid-base balance recovery and time-to-exhaustion running performance: a randomised crossover trial in recreational athletes.

This study investigated the effect of post-exercise sodium bicarbonate (NaHCO3) ingestion on acid-base balance recovery and time-to-exhaustion (TTE) running performance. Eleven male runners (stature, 1.80 ± 0.05 m; body mass, 74.4 ± 6.5 kg; maximal oxygen consumption, 51.7 ± 5.4 mL·kg-1·min-1) participated in this randomised, single-blind, counterbalanced and crossover design study. Maximal running velocity (v-V̇O2max) was identified from a graded exercise test. During experimental trials, participants repeated 100% v-V̇O2max TTE protocols (TTE1, TTE2) separated by 40 min following the ingestion of either 0.3 g·kg-1 body mass NaHCO3 (SB) or 0.03 g·kg-1 body mass sodium chloride (PLA) at the start of TTE1 recovery. Acid-base balance (blood pH and bicarbonate, HCO3-) data were studied at baseline, post-TTE1, after 35 min recovery and post-TTE2. Blood pH and HCO3- concentration were unchanged at 35 min recovery (p > 0.05), but HCO3- concentration was elevated post-TTE2 for SB vs. PLA (+2.6 mmol·L-1; p = 0.005; g = 0.99). No significant differences were observed for TTE2 performance (p > 0.05), although a moderate effect size was present for SB vs. PLA (+14.3 s; g = 0.56). Post-exercise NaHCO3 ingestion is not an effective strategy for accelerating the restoration of acid-base balance or improving subsequent TTE performance when limited recovery is available. Novelty: Post-exercise sodium bicarbonate ingestion did not accelerate the restoration of blood pH or bicarbonate after 35 min. Performance enhancing effects of sodium bicarbonate ingestion may display a high degree of inter-individual variation. Small-to-moderate changes in performance were likely due to greater up-regulation of glycolytic activation during exercise.

Sodium Bicarbonate Ingestion Improves Time-to-Exhaustion Cycling Performance and Alters Estimated Energy System Contribution: A Dose-Response Investigation.

This study investigated the effects of two sodium bicarbonate (NaHCO3) doses on estimated energy system contribution and performance during an intermittent high-intensity cycling test (HICT), and time-to-exhaustion (TTE) exercise. Twelve healthy males (stature: 1.75 ± 0.08 m; body mass: 67.5 ± 6.3 kg; age: 21.0 ± 1.4 years; maximal oxygen consumption: 45.1 ± 7.0 ml.kg.min-1) attended four separate laboratory visits. Maximal aerobic power (MAP) was identified from an incremental exercise test. During the three experimental visits, participants ingested either 0.2 g.kg-1 BM NaHCO3 (SBC2), 0.3 g.kg-1 BM NaHCO3 (SBC3), or 0.07 g.kg-1 BM sodium chloride (placebo; PLA) at 60 min pre-exercise. The HICT involved 3 × 60 s cycling bouts (90, 95, 100% MAP) interspersed with 90 s recovery, followed by TTE cycling at 105% MAP. Blood lactate was measured after each cycling bout to calculate estimates for glycolytic contribution to exercise. Gastrointestinal (GI) upset was quantified at baseline, 30 and 60 min post-ingestion, and 5 min post-exercise. Cycling TTE increased for SBC2 (+20.2 s; p = 0.045) and SBC3 (+31.9 s; p = 0.004) compared to PLA. Glycolytic contribution increased, albeit non-significantly, during the TTE protocol for SBC2 (+7.77 kJ; p = 0.10) and SBC3 (+7.95 kJ; p = 0.07) compared to PLA. GI upset was exacerbated post-exercise after SBC3 for nausea compared to SBC2 and PLA (p < 0.05), whilst SBC2 was not significantly different to PLA for any symptom (p > 0.05). Both NaHCO3 doses enhanced cycling performance and glycolytic contribution, however, higher doses may maximize ergogenic benefits.