Introduktion: Kosttillskott som kreatin och koffein har bevisade erogena effekter hos idrottare, men det finns flertalet kosttillskott som är mindre beprövade. Tidigare studier på bikarbonat har visat på prestationshöjande effekter men resultaten varierar. Bikarbonat har visat sig påverka det intramuskulära pH-värdet under högintensiv träning. Syfte: Syftet med studien var att undersöka prestationseffekterna av bikarbonat på CrossFit utövare under kort, högintensiv träning. Metod: Testerna utfördes på CrossFit utövare (n=7) där deltagarna fick antingen bikarbonat (0,3 g/kg/kroppsvikt) eller placebo 60-90 min innan testerna utfördes. Deltagarna fick utföra rodd och thrusters med skivstång under totalt 12 min. Antalet repetitioner, roddeffekt samt puls mätes under testutförandet. Studien är utfört med crossover samt dubbelblindat. Resultat: Resultatet visade inte på några signifikanta skillnader gällande varken antalet repetitioner, roddeffekter eller pulser mellan interventions- eller placebogruppen. Slutsats: De tidigare dokumenterade prestationshöjningarna skulle eventuellt kunna vara relevant för elitidrottare. Denna studie ger en inblick i huruvida de prestationshöjande effekterna av bikarbonat kan visa sig hos CrossFit utövare. / Introduction: Dietary supplements like creatine and caffeine has proven ergogenic effects on athletes. Studies on sodium bicarbonate has been shown to improve performance during short, sprint-like exercise, but the results varies. Sodium bicarbonate influences the intramuscular pH during high-intensity training. Purpose: The purpose of this study was to examine the effects of sodium bicarbonate on CrossFit athletes during short, high-intensity training. Method: The tests were conducted on CrossFit athletes (n=7) were the participants either were given a sodium bicarbonate or a placebo supplement. The supplements were ingested 60-90 min before tests were conducted and all exercise test were performed double-blind and cross-over. The participants rowed and performed thrusters during a total of 12 min. The number of repetitions, average effect on the rowing machine and heartrate were measured during.   Results: The result did not show any significant differences between the intervention group and the placebo group regarding number of repetitions, average rowing effect or heartrate. Conclusion: The previous documentated performance enhancing effects could potentially be relevant to elite athletes. This study might give an insight to the effects of sodium bicarbonate in CrossFit participants.