Investigating the Inverted-U Relationship Between Cognitive Performance and Plasma Epinephrine

Sponsor

National Taiwan Normal University (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05407259

Collaborator

(none)

Enrollment

Arms

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

Abstract Although acute resistance exercise has been suggested to enhance inhibitory control, a critical component of executive function, the mechanism by which acute exercise influences inhibitory control is unclear and there are methodological limitations in previous empirical studies. According to the locus coeruleus-norepinephrine (LC-NE) theory, the activity of the LC, the major releaser of NE in the brain, regulates inhibitory control. Because there is reciprocal communication between circulating epinephrine and the LC. Plasma epinephrine is chosen as the index of LC-NE activity. However, only one study in acute exercise-inhibitory control measured the plasma epinephrine. Therefore, this registered report aims to extend its findings by a four-arm crossover randomized controlled design with three different intensities, using free-weight, multiple-joint, and structural resistance exercises. Moreover, most studies showed some methodological limitations such as failing to report the process of randomization, implementing a familiarization of resistance exercise before the maximal strength test, and publishing the protocol. Without a transparent report on how the participants were allocated, the results were at risk of bias. Without a familiarization of resistance exercise, the maximal muscle strength was likely to be underestimated. Without publishing the protocol before data collection, these findings were threatened by undetected researchers' degrees of freedom such as HARKing (hypothesizing after the results are known), cherry picking, and p-hacking. This registered report will address the limitations of previous studies by incorporating cognitive and resistance exercise familiarization, transparently reporting the randomization process, and submitting it as a registered report.

Condition or Disease	Intervention/Treatment	Phase
Healthy Young Adults	Behavioral: Resistance exercise	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

None (Open Label)

Masking Description:

Blinding (masking) and controlling risk of bias Because of the nature of exercise interventions, the blinding of participants and experimenters is not applicable to our study. To reduce the threat of the placebo effect, we will ask participants for their expectations on cognitive performance, and these will be incorporated into our statistical analysis. Blinding of the outcome assessors is also not possible. However, all measurements of cognitive performance will be computerized and not involve human judgment. The data analyzers will not be blinded but will follow a pre-specified statistical analysis plan. These procedures will reduce the risk of bias arising from the lack of blinding of participants, experimenters, assessors, and data analyzers and the threat from researchers' degrees of freedom.

Primary Purpose:

Other

Official Title:

Investigating the Inverted-U Relationship Between Cognitive Performance and Plasma Epinephrine: A Registered Report of a Four-arm Crossover Randomized Controlled Trial

Anticipated Study Start Date :

Jun 1, 2022

Anticipated Primary Completion Date :

Sep 30, 2023

Anticipated Study Completion Date :

Dec 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
No Intervention: Control condition During the control condition, participants will be asked to read a book related to exercise for approximately 40 minutes.
Experimental: Low-intensity barbell resistance exercise Exercise: Barbell squat, barbell press, and barbell deadlift Number of sets: 3 Number of repetitions: 5 Intensity: 65% 1RM Training method: Circuit training (Squat set 1 ➔ Press set 1 ➔ Deadlift set 1 ➔ Squat set 2 ➔ Press set 2 ➔ Deadlift set 2 ➔ Squat set 3 ➔ Press set 3 ➔ Deadlift set 3) Rest interval between exercises and sets: ~3 minutes (Warm-up: 1 set of 5 repetitions for each exercise at 50% 1RM)	Behavioral: Resistance exercise There will be four conditions (three exercises and one control) on visits 3-6. For the three exercise conditions, all training parameters except intensity will be the same. The sets in high, moderate, and low intensity correspond to the rate of perceived exertion (0-10 scale) 7-9, 5-6, and 3-4, respectively. Therefore, the participants will perform 5 repetitions barbell squat, barbell press, and barbell deadlift with 8RM (78% 1RM), 11RM (72% 1RM), and 16RM (65% 1RM) for 3 sets Other Names: Resistance training
Experimental: Moderate-intensity barbell resistance exercise Exercise: Barbell squat, barbell press, and barbell deadlift Number of sets: 3 Number of repetitions: 5 Intensity: 72% 1RM Training method: Circuit training (Squat set 1 ➔ Press set 1 ➔ Deadlift set 1 ➔ Squat set 2 ➔ Press set 2 ➔ Deadlift set 2 ➔ Squat set 3 ➔ Press set 3 ➔ Deadlift set 3) Rest interval between exercises and sets: ~3 minutes (Warm-up: 1 set of 5 repetitions for each exercise at 50% 1RM)	Behavioral: Resistance exercise There will be four conditions (three exercises and one control) on visits 3-6. For the three exercise conditions, all training parameters except intensity will be the same. The sets in high, moderate, and low intensity correspond to the rate of perceived exertion (0-10 scale) 7-9, 5-6, and 3-4, respectively. Therefore, the participants will perform 5 repetitions barbell squat, barbell press, and barbell deadlift with 8RM (78% 1RM), 11RM (72% 1RM), and 16RM (65% 1RM) for 3 sets Other Names: Resistance training
Experimental: High-intensity barbell resistance exercise Exercise: Barbell squat, barbell press, and barbell deadlift Number of sets: 3 Number of repetitions: 5 Intensity: 78% 1RM Training method: Circuit training (Squat set 1 ➔ Press set 1 ➔ Deadlift set 1 ➔ Squat set 2 ➔ Press set 2 ➔ Deadlift set 2 ➔ Squat set 3 ➔ Press set 3 ➔ Deadlift set 3) Rest interval between exercises and sets: ~3 minutes (Warm-up: 1 set of 5 repetitions for each exercise at 50% 1RM)	Behavioral: Resistance exercise There will be four conditions (three exercises and one control) on visits 3-6. For the three exercise conditions, all training parameters except intensity will be the same. The sets in high, moderate, and low intensity correspond to the rate of perceived exertion (0-10 scale) 7-9, 5-6, and 3-4, respectively. Therefore, the participants will perform 5 repetitions barbell squat, barbell press, and barbell deadlift with 8RM (78% 1RM), 11RM (72% 1RM), and 16RM (65% 1RM) for 3 sets Other Names: Resistance training

Outcome Measures

Primary Outcome Measures

Inhibitory control (change between baseline and 5 minutes after intervention/control) [Baseline (before intervention) and 5 minutes after (post-task) intervention/control.]
The Inhibitory control (Stroop interference score) will be the mean incongruent reaction time minus the mean congruent reaction time. Lower scores mean a better outcome.
Inhibitory control (change between baseline and 20 minutes after intervention/control) [Baseline (before intervention) and 20 minutes after (post-task) intervention/control.]
The Inhibitory control (Stroop interference score) will be the mean incongruent reaction time minus the mean congruent reaction time. Lower scores mean a better outcome.
Inhibitory control (change between baseline and 35 minutes after intervention/control) [Baseline (before intervention) and 35 minutes after (post-task) intervention/control.]
The Inhibitory control (Stroop interference score) will be the mean incongruent reaction time minus the mean congruent reaction time. Lower scores mean a better outcome.
Inhibitory control (change between baseline and 50 minutes after intervention/control) [Baseline (before intervention) and 50 minutes after (post-task) intervention/control.]
The Inhibitory control (Stroop interference score) will be the mean incongruent reaction time minus the mean congruent reaction time. Lower scores mean a better outcome.
Information processing speed (change between baseline and 5 minutes after intervention/control) [Baseline (before intervention) and 5 minutes after intervention/control.]
The Information processing speed will be the mean simple reaction time. Lower scores mean a better outcome.
Information processing speed (change between baseline and 20 minutes after intervention/control) [Baseline (before intervention) and 20 minutes after intervention/control.]
The Information processing speed will be the mean simple reaction time. Lower scores mean a better outcome.
Information processing speed (change between baseline and 35 minutes after intervention/control) [Baseline (before intervention) and 35 minutes after intervention/control.]
The Information processing speed will be the mean simple reaction time. Lower scores mean a better outcome.
Information processing speed (change between baseline and 50 minutes after intervention/control) [Baseline (before intervention) and 50 minutes after intervention/control.]
The Information processing speed will be the mean simple reaction time. Lower scores mean a better outcome.

Secondary Outcome Measures

Epinephrine (change between baseline and immediately after intervention/control) [Baseline and immediately after intervention/control.]
Plasma epinephrine concentrations will be measured in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA) kit.
Epinephrine (change between baseline and 15 minutes after intervention/control) [Baseline and 15 minutes after intervention/control.]
Plasma epinephrine concentrations will be measured in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA) kit.
Epinephrine (change between baseline and 30 minutes after intervention/control) [Baseline and 30 minutes after intervention/control.]
Plasma epinephrine concentrations will be measured in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA) kit.
Epinephrine (change between baseline and 45 minutes after intervention/control) [Baseline and 45 minutes after intervention/control.]
Plasma epinephrine concentrations will be measured in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA) kit.
Epinephrine (change between baseline and 60 minutes after intervention/control) [Baseline and 60 minutes after intervention/control.]
Plasma epinephrine concentrations will be measured in duplicate using a commercially available enzyme-linked immunosorbent assay (ELISA) kit.

Eligibility Criteria

Criteria

Ages Eligible for Study:

20 Years to 40 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

healthy young male aged 18-40 years;
recreational resistance-trained (≥ 1 time/week for the previous 6 months);
free from cardiovascular, cerebrovascular, and neurological disorders and other chronic diseases;
free from any medical condition listed on the 2014 update of the Physical Activity Readiness Questionnaire (PAR-Q+);
non-smoker; and
normal or corrected-to-normal vision.

Exclusion Criteria:

athlete trained in a competitive sports team or engaging in exercise for more than 20 hours/week;
unable to perform any of the intervention exercises (barbell squat, press, and deadlift); or
color blind