Basically, three types of NaHCO3 supplementation protocols

can be applied: acute (single dose), chronic (multiple dose) and multiday acute supplementation (one dose per day before competition for consecutive days of competition). During the acute delivery mode participants take one single dose (mostly 0.3 g∙ click here kg-1 body mass NaHCO3) 60 to 90 min before the start of competition. During the chronic delivery mode participants take a daily amount of NaHCO3 (mostly 0.5 g∙ kg-1 body mass), divided in 2 to 3 portions, for several days before competition takes place. On the day of competition, no NaHCO3 is consumed [16, 17]. The multiday acute delivery mode comprises the ingestion of acute doses on consecutive days of competition. In contrast to the chronic loading protocol, acid–base balance is perturbed on every day during the multiday acute delivery mode. This fact leads to major differences regarding the acid–base status and accordingly the underlying mechanisms as well as the effectiveness of the different delivery modes. While the acute and chronic supplementation

protocols are scientifically well described, data on the effects of multiday acute supplementation are lacking. There are several studies, which investigated NaHCO3 ingestion during tournament-like sports, but only for single events. For example, it was shown PLX-4720 clinical trial that NaHCO3 supplementation increases tennis performance [18] but does not affect prolonged intermittent cycling exercise performance [19]. However, up to date, no study investigated the effect of a consecutive multiday supplementation on consecutive multiday performance. Since consecutive, acute-load daily use of NaHCO3 might represent an interesting option to increase performance during multiday competitions or tournaments that involve exercise

in the heavy and severe intensity domains, further research is warranted. In particular, scientific knowledge is limited with respect to the recovery of the body’s acid–base balance after high-intensity exercise with NaHCO3 supplementation and consequently, the initial positions on the following days remain elusive. Thus, the purpose of this randomized, SPTLC1 placebo-controlled, double-blind interventional CFTRinh-172 cost crossover study was to investigate if multiday acute NaHCO3 supplementation in well-trained endurance athletes leads to changes in T lim at CP during constant-load cycle ergometer trials on a day-to-day basis with daily acute NaHCO3 vs. placebo supplementation for 5 days. Furthermore, we aimed to investigate if differences in T lim can be explained by alterations in [HCO3 -] and if the high amount of ingested Na+ influences plasma volume (PV) and thus [HCO3 -].