Acute Metabolic and Perceptive Responses to a Multi-Ingredient Pre-Workout Supplement and CrossFit®-Style Exercise
Abstract (300 words maximum)
Pre-workout supplements often contain several ingredients known to alter blood flow and substrate utilization, but no study has investigated the acute effects of such formulations on CrossFit® (CF) performance. PURPOSE: To examine the effect of a pre-workout supplement and exercise duration on metabolism and perceived effort following a CF workout. METHODS: Experienced adults (≥2 years of CF-experience) completed four weekly visits in randomized, cross-over fashion. Upon arrival, participants completed pre-exercise subjective ratings before ultrasound images of vastus lateralis (VL) and rectus femoris (RF) were collected to quantify cross-sectional area (cm2; CSA). They were connected to a metabolic cart for 10 minutes while oxygen consumption (VO2) and respiratory quotient (RQ) were monitored and then donated a blood sample to measure lactate concentrations. Participants then consumed either S or placebo (P), rested 40 minutes, and then completed a 5- or 15-minute circuit of rowing, barbell thrusters, and box jumps for ‘as many reps as possible’. All PRE-assessments were repeated post-exercise. RESULTS: Repeated measures analysis of variance revealed significant (p < 0.05) condition x time interactions for CSA, blood lactate, and VO2. Except for VL CSA (~0.9 cm2 difference between 5S and 5P, p = 0.018), no pre-exercise differences were observed. Post-exercise CSA (RF & VL) was approximately 8.8-11.7% greater during S (both durations) compared to P (both durations). Likewise, blood lactate was 22.4% higher following S (both durations) than P (both durations), though differences between 5S and 5P were not seen until 5-minutes post-exercise. VO2 was 12.2-12.4% greater after 5S compared to P (both durations), whereas 15S was 7.6% higher than 15P but no different than 5P. No other differences were noted. CONCLUSION: The pre-workout supplement led to greater acute increases in muscle size, oxygen consumption, and blood lactate at the same perceived effort.
Academic department under which the project should be listed
WCHHS - Exercise Science and Sport Management
Primary Investigator (PI) Name
Gerald Mangine
Additional Faculty
Jacob Grazer, Exercise Science and Sport Management, jgrazera@kennesaw.edu
Tiffany Esmat, Exercise Science and Sport Management, tesmat@kennesaw.edu
John McLester, Exercise Science and Sport Management, jmcleste@kennesaw.edu
Acute Metabolic and Perceptive Responses to a Multi-Ingredient Pre-Workout Supplement and CrossFit®-Style Exercise
Pre-workout supplements often contain several ingredients known to alter blood flow and substrate utilization, but no study has investigated the acute effects of such formulations on CrossFit® (CF) performance. PURPOSE: To examine the effect of a pre-workout supplement and exercise duration on metabolism and perceived effort following a CF workout. METHODS: Experienced adults (≥2 years of CF-experience) completed four weekly visits in randomized, cross-over fashion. Upon arrival, participants completed pre-exercise subjective ratings before ultrasound images of vastus lateralis (VL) and rectus femoris (RF) were collected to quantify cross-sectional area (cm2; CSA). They were connected to a metabolic cart for 10 minutes while oxygen consumption (VO2) and respiratory quotient (RQ) were monitored and then donated a blood sample to measure lactate concentrations. Participants then consumed either S or placebo (P), rested 40 minutes, and then completed a 5- or 15-minute circuit of rowing, barbell thrusters, and box jumps for ‘as many reps as possible’. All PRE-assessments were repeated post-exercise. RESULTS: Repeated measures analysis of variance revealed significant (p < 0.05) condition x time interactions for CSA, blood lactate, and VO2. Except for VL CSA (~0.9 cm2 difference between 5S and 5P, p = 0.018), no pre-exercise differences were observed. Post-exercise CSA (RF & VL) was approximately 8.8-11.7% greater during S (both durations) compared to P (both durations). Likewise, blood lactate was 22.4% higher following S (both durations) than P (both durations), though differences between 5S and 5P were not seen until 5-minutes post-exercise. VO2 was 12.2-12.4% greater after 5S compared to P (both durations), whereas 15S was 7.6% higher than 15P but no different than 5P. No other differences were noted. CONCLUSION: The pre-workout supplement led to greater acute increases in muscle size, oxygen consumption, and blood lactate at the same perceived effort.