The Effects of a Carbohydrate Hydrogel System for the Delivery of Bicarbonate Mini-Tablets on Acid–Base Buffering and Gastrointestinal Symptoms in Resting Well-trained Male Cyclists

Background: A new commercially available sodium bicarbonate (SB) supplement claims to limit gastrointestinal (GI) discomfort and increase extracellular buffering capacity. To date, no available data exists to substantiate such claims. Therefore, the aim of this study was to measure blood acid–base balance and GI discomfort responses following the ingestion of SB using the novel “Bicarb System” (M-SB). Twelve well-trained male cyclists completed this randomised crossover designed study. Maximal oxygen consumption was determined in visit one, whilst during visits two and three participants ingested 0.3 g∙kg−1 BM SB using M-SB (Maurten, Sweden) or vegetarian capsules (C-SB) in a randomised order. Finger prick capillary blood samples were measured every 30 min for pH, bicarbonate (HCO3−), and electrolytes (potassium, chloride, calcium, and sodium), for 300 min. Visual analogue scales (VAS) were used to assess GI symptoms using the same time intervals. Results: Peak HCO3− was 0.95 mmol∙L−1 greater following M-SB (p = 0.023, g = 0.61), with time to peak HCO3− achieved 38.2 min earlier (117 ± 37 vs. 156 ± 36 min; p = 0.026, r = 0.67) and remained elevated for longer (p = 0.043, g = 0.51). No differences were observed for any electrolytes between the conditions. Aggregated GI discomfort was reduced by 79 AU following M-SB (p < 0.001, g = 1.11), with M-SB reducing stomach cramps, bowel urgency, diarrhoea, belching, and stomach-ache compared to C-SB. Conclusions: This is the first study to report that M-SB can increase buffering capacity and reduce GI discomfort. This presents a major potential benefit for athletes considering SB as an ergogenic supplement as GI discomfort is almost eliminated. Future research should determine if M-SB is performance enhancing

Post-exercise Supplementation of Sodium Bicarbonate Improves Acid Base Balance Recovery and Subsequent High-Intensity Boxing Specific Performance

The aim of this study was to assess the effects of post-exercise sodium bicarbonate (NaHCO3) ingestion (0.3 g.kg−1 body mass) on the recovery of acid-base balance (pH, HCO−3, and the SID) and subsequent exercise performance in elite boxers. Seven elite male professional boxers performed an initial bout of exhaustive exercise comprising of a boxing specific high-intensity interval running (HIIR) protocol, followed by a high-intensity run to volitional exhaustion (TLIM1). A 75 min passive recovery then ensued, whereby after 10 min recovery, participants ingested either 0.3 g.kg−1 body mass NaHCO3, or 0.1 g.kg−1 body mass sodium chloride (PLA). Solutions were taste matched and administered double-blind. Participants then completed a boxing specific punch combination protocol, followed by a second high-intensity run to volitional exhaustion (TLIM2). Both initial bouts of TLIM1 were well matched between PLA and NaHCO3 (ICC; r = 0.94, p = 0.002). The change in performance from TLIM1 to TLIM2 was greater following NaHCO3 compared to PLA (+164 ± 90 vs. +73 ± 78 sec; p = 0.02, CI = 45.1, 428.8, g = 1.0). Following ingestion of NaHCO3, pH was greater prior to TLIM2 by 0.11 ± 0.02 units (1.4%) (p < 0.001, CI = 0.09, 0.13, g = 3.4), whilst HCO−3 was greater by 8.8 ± 1.5 mmol.l−1 (26.3%) compared to PLA (p < 0.001, CI = 7.3, 10.2, g = 5.1). The current study suggests that these significant increases in acid base balance during post-exercise recovery facilitated the improvement in the subsequent bout of exercise. Future research should continue to explore the role of NaHCO3 supplementation as a recovery aid in boxing and other combat sports

The Effects of Astaxanthin on Cognitive Function and Neurodegeneration in Humans: A Critical Review

Oxidative stress is a key contributing factor in neurodegeneration, cognitive ageing, cognitive decline, and diminished cognitive longevity. Issues stemming from oxidative stress both in relation to cognition and other areas, such as inflammation, skin health, eye health, and general recovery, have been shown to benefit greatly from antioxidant use. Astaxanthin is a potent antioxidant, which has been outlined to be beneficial for cognitive function both in vitro and in vivo. Given the aforementioned promising effects, research into astaxanthin with a focus on cognitive function has recently been extended to human tissue and human populations. The present critical review explores the effects of astaxanthin on cognitive function and neurodegeneration within human populations and samples with the aim of deciphering the merit and credibility of the research findings and subsequently their potential as a basis for therapeutic use. Implications, limitations, and areas for future research development are also discussed. Key findings include the positive impacts of astaxanthin in relation to improving cognitive function, facilitating neuroprotection, and slowing neurodegeneration within given contexts

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), 60 minutes pre-exercise. The HICT involved 3 x 60 s cycling bouts (90%, 95%, 100% MAP) interspersed with 90 s recovery, followed by TTE cycling at 105% MAP. Blood lactate was sampled after each cycling bout to calculate estimates for glycolytic contribution to exercise. Gastrointestinal (GI) upset was quantified at baseline, 30 minutes and 60 minutes post-ingestion, and 5 minutes 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 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). Both NaHCO3 doses enhanced cycling performance and glycolytic contribution, however, higher doses may maximise ergogenic benefits

Four Weeks of Probiotic Supplementation Alters the Metabolic Perturbations Induced by Marathon Running: Insight from Metabolomics

Few data are available that describe how probiotics influence systemic metabolism during endurance exercise. Metabolomic profiling of endurance athletes will elucidate mechanisms by which probiotics may confer benefits to the athlete. In this study, twenty-four runners (20 male, 4 female) were block randomised into two groups using a double-blind matched-pairs design according to their most recent Marathon performance. Runners were assigned to 28-days of supplementation with a multi-strain probiotic (PRO) or a placebo (PLB). Following 28-days of supplementation, runners performed a competitive track Marathon race. Venous blood samples and muscle biopsies (vastus lateralis) were collected on the morning of the race and immediately post-race. Samples were subsequently analysed by untargeted 1H-NMR metabolomics. Principal component analysis (PCA) identified a greater difference in the post-Marathon serum metabolome in the PLB group vs. PRO. Univariate tests identified 17 non-overlapped metabolites in PLB, whereas only seven were identified in PRO. By building a PLS-DA model of two components, we revealed combinations of metabolites able to discriminate between PLB and PRO post-Marathon. PCA of muscle biopsies demonstrated no discernible difference post-Marathon between treatment groups. In conclusion, 28-days of probiotic supplementation alters the metabolic perturbations induced by a Marathon. Such findings may be related to maintaining the integrity of the gut during endurance exercise