Peri-Rx with Caffeine's (by Barbell Medicine) ability to improve muscular endurance is rated as 1.73 out of 3. This rating means the evidence is mixed on the product's ability to deliver on this claim. While some of the evidence supports its use, other evidence does not. Using Peri-Rx with Caffeine to improve muscular endurance may lead to positive results. This rating is different from the product's overall rating and is based on what peer reviewed journal articles conclude on its ability to perform this one claim. This page contains an indepth analysis on how this claim-rating was calculated.

Note: The ratings on this page only deal with Peri-Rx with Caffeine's ability to improve muscular endurance. To view the product's overall rating, visit the product's main page: Peri-Rx with Caffeine.

Table of Contents

  1. Simple Report
  2. Detailed Report
  3. References

Simple Report

Detailed Report

The detailed report is an in-depth analysis on how Peri-Rx with Caffeine's rating for this particular claim was calculated.

Claim Effectiveness Ratings

Each supplement product is a blend of ingredients. The database uses peer reviewed journal articles to rate the ingredients. These ratings are also used to rate how well products perform overall as well as on individual claims.

The supplement ingredients listed in table below are identified as affecting Peri-Rx with Caffeine's ability to improve muscular endurance. The rating next to the ingredient describes the ingredient's ability to improve muscular endurance. These ratings are averaged together and provide the product's overall ability to deliver on the same claim.

Ingredients Improve Muscular Endurance Rating
Branched Chain Amino Acids 1 out of 3
Creatine Monohydrate 2 out of 3
Beta Alanine 1.8 out of 3
Citrulline Malate 2.3 out of 3
Betaine 1.7 out of 3
Caffeine 1.6 out of 3
Product's Claim Effectiveness Rating 1.73 out of 3

Claim Research Ratings

The research rating describes how well an ingredient's ability to perform a certain claim (such as improve muscular endurance) has been researched. This rating is based on the amount of studies contained in the database on a particular ingredient and claim. Ingredient research ratings are averaged together to from the product's research rating for this specific cliam.

This rating is important because we need to know if there is enough research to make a valid conclusion on a product's worthiness. Ratings above 80 are ideal. Anything below 60 means there is not enoguh research to make a valid conclusion one way or another on a product's ability to deliver on this particular claim.

Ingredients Improve Muscular Endurance Research Rating
Branched Chain Amino Acids
Creatine Monohydrate
Beta Alanine
Citrulline Malate
Product's Claim Research Rating


The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance
Effects of creatine supplementation on the onset of neuromuscular fatigue threshold and muscle strength in elderly men and women (64 - 86 years)
Effects of Coffee and Caffeine Anhydrous Intake During Creatine Loading
Effects of creatine loading on muscular strength and endurance of female softball players
Mg2+-creatine chelate and a low-dose creatine supplementation regimen improve exercise performance
β-alanine supplementation improves isometric endurance of the knee extensor muscles
Effects of β-Alanine on Body Composition and Performance Measures in Collegiate Women
β-Alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters
Beta-alanine supplementation improves isometric, but not isotonic or isokinetic strength endurance in recreationally strength-trained young men
Citrulline Malate Enhances Athletic Anaerobic Performance and Relieves Muscle Soreness
Effects of supplemental citrulline malate ingestion during repeated bouts of lower-body exercise in advanced weightlifters
Effects of Supplemental Citrulline-Malate Ingestion on Blood Lactate, Cardiovascular Dynamics, and Resistance Exercise Performance in Trained Males
The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men
Effect of betaine supplementation on power performance and fatigue
Effects of betaine on body composition, performance, and homocysteine thiolactone
The acute effects of a caffeine-containing supplement on strength, muscular endurance, and anaerobic capabilities
Acute ingestion of sugar-free red bull energy drink has no effect on upper body strength and muscular endurance in resistance trained men
Acute Specific Effects of Caffeine-containing Energy Drink on Different Physical Performances in Resistance-trained Men
Caffeine ingestion acutely enhances muscular strength and power but not muscular endurance in resistance-trained men
The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance
The effect of ephedra and caffeine on maximal strength and power in resistance-trained athletes
Effects of Coffee and Caffeine Anhydrous Intake During Creatine Loading
Acute caffeine ingestion enhances strength performance and reduces perceived exertion and muscle pain perception during resistance exercise