Abstract

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 the survey. The majority of respondents reported the length of current or past MIPS consumption as greater than one year (n = 630, 72.2%), with ingestion frequencies primarily of four (n = 210, 24.1%) or five (n = 212, 24.3%) days per week of training. In addition, the three most popular goals for ingesting MIPS were increased energy and focus (n = 776, 89.0%), muscular endurance (n = 325, 37.3%), and blood flow or “pump” (n = 322, 37.0%). Although most users reported ingesting one serving size with each use, 14% reported ingesting two or more, and 18% indicated they ingest MIPS more than once per day. Importantly, over half (54%) of the respondents reported experiencing side-effects following MIPS use, including skin reactions, heart abnormalities, and nausea. Females were more likely than males to experience these side effects, despite being less likely to consume two or more serving sizes per dose. Our findings also indicated that MIPS users should consume no more than the recommended serving size of a given supplement, as the potentially significant variability in the caffeine content of MIPS products is compounded as more doses are consumed. Furthermore, MIPS users should minimize the ingestion of other supplements which contain high levels of niacin and caffeine, as the concurrent consumption of such products may put users above the tolerable upper limits for these substances.

Introduction

The use of dietary supplements to enhance exercise performance is becoming an increasingly popular strategy, particularly among fitness enthusiasts and athletes. As of 2012, a report by Kantor et al. [1] indicated that approximately 52% of US adults reported using dietary supplements on a regular basis, which is similar to trends of use reported from the early 2000s [2]. There is reason to believe these prevalence rates may be even higher today, as economic sales from dietary supplements have continued to rise. In 2016, it was estimated that the overall economic impact of the dietary supplement industry was approximately $122 billion, with future projections estimating a potential worth of nearly $278 billion by the year 2024 [3]. With such an increase in dietary supplement use, it is important to examine the behaviors of supplement users and key motivators for use in order to better understand potential areas for concern and identify strategies to ensure safe and effective dietary supplement use.

A sub-set of dietary supplements that has garnered attention from regular exercisers are multi-ingredient pre-workout supplements. These products often contain a blend of ingredients purported to improve acute exercise performance following ingestion, which may augment training adaptations if ingested over a longer period when used in conjunction with a structured training program. A recent review by Harty and Zabriskie et al. [4] summarized the available literature regarding the efficacy and safety of MIPS use with regards to single ingestion and repeated use. There appears to be supporting evidence that MIPS supplementation can improve exercise performance following a single use, particularly in the context of muscular endurance-based activities [4,5,6,7,8,9,10,11,12]. Furthermore, extended use appears to enhance training adaptations with a low risk for adverse events [4,13,14,15,16,17,18,19], assuming consumers are following the manufacturer recommendations for proper use.

To date, a paucity of information is available regarding the usage patterns of individuals who routinely ingest MIPS. Every MIPS product has a specific serving size recommendation for consumption. However, users may opt to consume less or more than the recommended serving size, which could present unknown benefits or risks. The usage patterns of MIPS users are relevant in the light of findings from a recent study that examined the common ingredient profiles of top-selling pre-workout supplements [20]. The authors of this study indicated three important findings regarding pre-workout supplement labels: a) Many ingredients are under-dosed when compared to evidence-based guidelines on recommended doses; b) many ingredient quantities are not provided; and c) some ingredients, such as niacin, may be over-dosed and potentially dangerous, particularly if consumers ingest other niacin containing compounds. Thus, highlighting consumers’ perceptions of their dosing regimens and feelings of safety is important. Therefore, the aim of the current study was to examine characteristics of MIPS users, their common patterns/habits of MIPS ingestion, and their associated feelings about the effectiveness and safety of this class of supplements.

FOR THE COMPLETE STUDY PLEASE VISIT: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520716/