Kinesiology Commons^™

Caffeine’S Impact On Heart Rate Variability During Short-Term Exercise In University Students, Maya J. Spinler, Morgan M. Payne, Christopher Carroll Dr.

Human Kinetics & Applied Health Sciences Student Works

The primary objective is to explore the physiological effects of caffeine on intra-bout exercise-induced blood pressure (BP) and heart rate (HR) deceleration resulting from repeated anaerobic exercise cycling in active university students. Use of caffeinated stimulants has increased in recent years, particularly in the exercise setting. The cardiovascular system (CS) is an essential piece of exercise physiology and is controlled by the autonomic nervous system (ANS). Caffeine has a known effect on the CS during acute exercise. What is not well solidified is the connection between caffeine and exercise-induced markers, such as heart rate recovery (HRR) and BP. Participants underwent …

A Dose-Response Study To Examine Paraxanthine's Impact On Energy Expenditure, Hunger, Appetite, And Lipolysis, Kristen N. Gross, Leah E. Allen, Anthony M. Hagele, Joesi M. Krieger, Paige J. Sutton, Esther Duncan, Petey W. Mumford, Ralf Jäger, Martin Purpura, Chad M. Kerksick

Faculty Scholarship

This study investigated if paraxanthine (PX) impacts energy expenditure, lipolysis and perceptual responses. In a randomized, double-blind, placebo-controlled, crossover fashion, 21 adults (13 M, 8 F; 26.0 ± 6.4 years, 174.9 ± 11.5 cm, 81.0 ± 15.7 kg body mass, 26.3 ± 3.4 kg/m2) consumed a placebo (PLA), 100 mg (PX100), 200 mg (PX200), and 300 mg of PX (PX300, enfinity®, Ingenious Ingredients, L.P. Lewisville, TX, USA). Venous blood was collected 0, 30, 60, 90, 120 and 180 min (min) after ingestion and analyzed for glycerol and free fatty acids. Resting hemodynamics, metabolic rate and perceptual indicators of hunger, appetite …

International Society Of Sports Nutrition Position Stand: Coffee And Sports Performance, Lonnie M. Lowery, Dawn E. Anderson, Kelsey F. Scanlon, Abigail Stack, Guillermo Escalante, Sara C. Campbell, Chad M. Kerksick, Michael T. Nelson, Tim N. Vandusseldorp, Douglas S. Kalman, Bill I. Campbell, Richard B. Kreider, Jose Antonio

Faculty Scholarship

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:

(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).

(2) Coffee’s constituents, including but not limited to caffeine, have neuromuscular, …

Prevalence And Amounts Of Common Ingredients Found In Energy Drinks And Shots, Andrew R. Jagim, Patrick S. Harty, Abdelrahman R. Barakat, Jacob L. Erickson, Victoria Carvalho, Chinguun Khurelbaatar, Clayton L. Camic, Chad M. Kerksick

Faculty Scholarship

Background: Energy drinks are one of the most popular packaged beverage products consumed within the United States (US). Energy drinks are considered a functional beverage, a category that also includes sports drinks and nutraceutical beverages. Purpose: The focus of the current study was to examine the nutrition fact panels of the top selling commercially available energy drink and energy shot products within the US to characterize common ingredient profiles to help establish a standard definition and ingredient profile of energy drinks and energy shots for consumers, health care practitioners, and researchers. Methods: The top 75 commercially available energy drinks and …

Neuromuscular Factors Contributing To Reductions In Muscle Force After Repeated, High-Intensity Muscular Efforts, Benjamin J.C. Kirk, Gabriel S. Trajano, Timothy S. Pulverenti, Grant Rowe, Anthony J. Blazevich

Publications and Research

Multiple neuromuscular processes contribute to the loss of force production following repeated, high-intensity muscular efforts; however, the relative contribution of each process is unclear. In Experiment 1, 16 resistance trained men performed six sets of unilateral isometric plantar flexor contractions of the right leg (3 s contraction/2 s rest; 85% maximal voluntary contraction torque; 90-s inter-set rest) until failure with and without caffeine ingestion (3 mg kg-1) on two separate days. Corticospinal excitability and cortical silent period (cSP) were assessed before and immediately, 10 and 20 min after the exercise. In Experiment 2, electrically evoked tetanic force and persistent inward …

Common Habits, Adverse Events, And Opinions Regarding Pre-Workout Supplement Use Among Regular Consumers, Andrew R. Jagim, Clayton L. Camic, Patrick S. Harty

Faculty Scholarship

The purpose of the present study was to examine characteristics of multi-ingredient pre-workout supplement (MIPS) users, their common patterns/habits of MIPS ingestion, and their associated feelings about the effectiveness and safety of this class of supplements. An online electronic survey was distributed through social media to assess self-reported supplementation practices and preferences among adult males and females who reported regular MIPS use. A total of 1045 individuals responded, with 872 of these individuals (males: n = 636, 72.9%; females: n = 233, 26.7%; mean ± SD; age = 27.7 ± 7.9 years; training age = 8.2 ± 7.3 years) completing …

Citrus Aurantium And Caffeine Complex Versus Placebo On Biomarkers Of Metabolism: A Double Blind Crossover Design, Brian Kliszczewicz, Emily Bechke, Cassie Williamson, Zackery Green

Faculty and Research Publications

BACKGROUOND: The purpose of this study was to examine resting the metabolic response to the ingestion of a complex containing Citrus Aurantium + Caffeine (CA + C) and if its consumption influences metabolic recovery following a high-intensity anaerobic exercise bout in habitual caffeine users. METHODS: Ten physically active males (25.1 ± 3.9 years; weight 78.71 ± 9.53 kg; height 177.2 ± 4.6 cm; body fat 15.5 ± 3.13%) participated in this study. This study was performed in a double-blind, randomized crossover fashion consisting of two exhaustive exercise protocols. On each visit the participants consumed either a CA + C (100 …

Common Ingredient Profiles Of Multi-Ingredient Pre-Workout Supplements, Andrew R. Jagim, Patrick S. Harty, Clayton L, Camic

Faculty Scholarship

Multi-ingredient pre-workout supplements are a popular class of dietary supplements which are purported to improve exercise performance. However, the composition of these products varies substantially between formulations, thus making comparisons challenging. Therefore, the purpose of this study was to identify a common ingredient profile of top-selling pre-workout supplements and to compare ingredient dosages to established efficacious values. The top 100 commercially available pre-workout products were analyzed for listed ingredients and amounts, if available, from the supplement facts panel. The mean ± SD number of ingredients per supplement (n = 100) was 18.4 ± 9.7 with 8.1 ± 9.9 of these …

Acute Effect Of Caffeine Intake On Hemodynamics After Resistance Exercise In Young Non-Hypertensive Subjects, Diego Souza, Juliano Cosanatto, Roberto Poton, Jeffrey Willardson, Marcos Polito

Faculty Research and Creative Activity

This study aimed to examine the effect of caffeine on hemodynamics after a resistance exercise session. Fifteen subjects completed two randomly ordered experimental resistance exercise sessions 45 min after the ingestion of either caffeine (4 mg.kg-1) or placebo. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were measured before consuming caffeine; SBP, DBP, MAP, heart rate, stroke volume, cardiac output and peripheral vascular resistance (PVR) were measured immediately before and after each of the sessions; SBP, DBP and MAP were measured for 9 hours after sessions. Caffeine increased (p < 0.05) pre-exercise DBP and MAP. In caffeine and placebo conditions significant decreases (p < 0.05) were noted in SBP, MAP, and PVR between the pre- and post-exercise time points. Notwithstanding, the mean values for SBP, DBP and MAP during the 9 h of post-exercise monitoring were increased (p < 0.05) for the caffeine. In conclusion, the cardiovascular effects of caffeine are different over the post-exercise period after resistance exercise in normotensive young adults.

Comparison Of The Effect Of Caffeine Ingestion On Time To Exhaustion Between Endurance Trained And Untrained Men, Steven Porterfield, Jon Linderman, Lloyd L. Laubach, Corinne M. Daprano

Health and Sport Science Faculty Publications

This study compared the ergogenic effects of caffeine on men who were endurance trained to those who were untrained. The study was a double-blind, placebo-controlled crossover experimental design. Ten endurance trained men (mean age 24.4 ± 2.0 yrs, weight 79.4 ± 8.5 kg, predicted VO2 max 46.3 ± 1.8 mL·kg-1·min-1) and 10 untrained men (mean age 22.8 ± 1.9 yrs, weight 88.9 ± 9.9 kg, predicted VO2 max 37.6 ± 2.7 mL·kg-1·min-1) completed two cycle ergometer trials to exhaustion at 80% of their predicted workload max 30 min after ingesting either 5 mg·kg-1 of body weight of caffeine or a …