The Acute Effects of Preworkout Supplement Ingestion and Whole‐Body Resistance Exercise on Clinical Safety Markers in Resistance‐Trained Males

Abstract

PURPOSETo examine the acute effects of ingesting a multi‐ingredient preworkout supplement (PWS) and conducting a whole‐body resistance exercise on clinical safety markers before and following exercise.METHODSWe recruited eight apparently healthy resistance‐trained males with at least six months immediate prior history of resistance training (19±1.1 yr, 173±2.6 cm, 66±2.9 kg, and 13.6±3% body fat) to participate in a randomized, double‐blind, crossover, and placebo‐controlled manner. We instructed participants to maintain their current diet and training regimens throughout the study. Supplements were a 6.5 g maltodextrin placebo (PL) and a commercially available PWS containing 1.6 g beta‐alanine, 1.0 g creatine nitrate, 1.0 g arginine alpha‐ketoglutarate, 321 mg explosive energy blended (including 160 mg caffeine anhydrous, l‐tyrosine, Tea Cor, tetramethyluric acid), 250 mg ascorbic acid, 30 mg niacinamide, 500 mcg vitamin B6, 150 mcg folate, and 20 mcg vitamin B12. In the first and second sessions, which were interspersed with a seven‐day washout period, participants ingested their assigned supplement 30 min before exercise. The exercise including a whole‐body resistance exercise initiated 30‐min after supplement ingestion. Blood samples were taken before, immediately after, and an hour following exercise. The measured blood markers included alkaline phosphatase (ALP), aspartate transaminase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine, and lactate. Repeated‐measures ANOVA and Bonferroni tests were used to analyze data. Results are expressed as mean±SD.RESULTSAnalysis of data demonstrated no significant between‐group differences for any biomarkers associated with liver enzymes such as ALP, AST, and ALT; kidney enzymes, including BUN and creatinine function; and lactate levels (all makers, p>0.05).CONCLUSIONThe acute ingestion of the PWS examined in the current study indicated no adverse effects on liver enzymes, kidney enzymes, and lactate levels, with respective responses being similar to treatment with a PL treatment. These findings agree with other studies testing similar ingredients, and more extended studies appear to be safe to perform on performance‐related outcomes.