The Effect of Breakfast Consumption on Afternoon Resistance Training Performance

OVERVIEW

This study is a randomized crossover trail examining the effect of breakfast consumption or omission on afternoon resistance training performance. Resistance-trained adults will complete a resistance training workout comprised of barbell back squat, barbell bench press, and barbell conventional deadlift following either consuming breakfast and lunch, or the same amount of food consumed solely at lunch. For each testing session the participants will be provided with all food to consume prior to arriving at the laboratory. Major performance outcomes will be total repetition volume completed for each exercise (i.e. bench press, squat, and deadlift) and the entire workout (each individual trial), along with barbell kinematics for each exercise.

Participants will report to the laboratory on three separate occasions, with 3 to 10 days between each visit. At the first visit, after initial screening and provision of informed consent, each participant will undergo a performance screening and familiarization session to confirm eligibility and become accustomed to the study procedures. This familiarization session will include initial assessments of bench press, barbell back squat, and conventional deadlift maximal strength in order to determine final eligibility. Additionally, body composition will be assessed via dual-energy X-ray absorptiometry and digital anthropometry at this session for descriptive purposes. Following the familiarization session, each participant will complete two laboratory visits consisting of completion of the resistance training workout described below after consuming the provided meals either divided between breakfast and lunch (~3-4 hours after breakfast), or solely at lunch. This will ensure each participant consumes identical quantities and types of foods prior to both exercise sessions. Thus, the only difference will be the food distribution as two meals (breakfast and lunch) or one meal (lunch). Throughout the study, participants will be asked to maintain their normal lifestyle practices. In addition, participants will report their dietary intake during the 24-hour period prior to the first testing session and will be asked to replicate this intake during the 24-hour period prior to the subsequent testing sessions. A background questionnaire will also be completed to assess general supplement use.

PURPOSE

The purpose of this investigation is to examine the effect of breakfast consumption or omission on afternoon resistance training performance in habitual breakfast consumers and non-consumers.

GENERAL HYPOTHESIS

It is hypothesized that afternoon resistance training performance will be impaired in habitual breakfast consumers when breakfast is omitted, but similar decrements will not be observed in habitual non-consumers.

HYPOTHESES TO BE TESTED/SPECIFIC AIMS

Specific Aim 1. To determine the effect of breakfast consumption on afternoon resistance training performance.

Hypothesis. It is hypothesized that afternoon resistance training performance will not be impacted by breakfast consumption or omission when the cohort is examined as a whole.

Specific Aim 2. To determine whether habitual breakfast consumption patterns impact afternoon resistance training performance following consumption or omission of breakfast.

Hypothesis. It is hypothesized that habitual breakfast consumption patterns will impact the effect of breakfast consumption on resistance training performance. More specifically, performance will be negatively affected by the omission of breakfast in those who habitually consume breakfast. Yet the omission of breakfast will not negatively impact resistance training performance in those that regularly do not consume breakfast.

Specific Aim 3. To determine the impact of breakfast consumption on subjective responses throughout an afternoon resistance training session.

Hypothesis. It is hypothesized that subjective responses during afternoon resistance training will not be impacted by breakfast consumption or omission when the cohort is examined as a whole.

Specific Aim 4. To determine whether habitual breakfast consumption patterns influence subjective responses throughout an afternoon resistance training session, following consumption or omission of breakfast.

Hypothesis. It is hypothesized that worsened subjective responses will be observed after breakfast omission only in those who habitually consume breakfast.

Inclusion criteria

• Between the ages of 18 and 40
• Body mass between 50 - 110 kg (110-242 lb)
• Generally healthy (defined as an absence of any disease or medical condition which could potentially be negatively affected by consumption of the commercially available dietary supplements or performance of exercise, including but not limited to musculoskeletal or cardiovascular diseases).
• Resistance-trained, defined as completing 2+ resistance training sessions per week for at least three months prior to screening.
• Participants must self-report either consuming or skipping breakfast ≥ 5 times per week for three months prior to screening.
• Participants must have reported regular training of the lower body through a multi-joint exercise such as the squat or leg press at least once weekly during the three-month period prior to screening.
• Participants must have reported regular training of the bench press or chest press variation at least once weekly during the three-month period prior to screening.
• Participants must have reported regular training of the deadlift or deadlift variation at least once weekly during the three-month period prior to screening.
• Female participants will be required to bench press ≥ 0.5 x body mass, barbell back squat ≥ 0.75 x body mass, and deadlift ≥ 1.0 x body mass to be eligible or this study.
• Male participants will be required to bench press ≥ 1.0 x body mass, barbell back squat ≥ 1.375 x body mass, and deadlift ≥ 1.75 x body mass to be eligible or this study.

Exclusion criteria

• Failing to meet any of the aforementioned inclusion criteria.
• Pregnant or breastfeeding (for female participants)
• Taking prescription medication which could reasonably make participation unsafe for the participant or influence study outcomes
• An inability to complete resistance exercise due to injury or medical condition
• Inability to complete a 16 hour fast.
• Allergy to any of the ingredients in the provided breakfast and lunch.
• Current use of anabolic steroids
• Presence of a pacemaker or other implanted electrical device.
• Inability to perform the exercises with safe and proper form as determined by members of the research team.