RecruitingNAINTERVENTIONAL

Validating IAAO for Muscle Outcomes

This research aims to find a new, less invasive way to understand how our bodies use protein to build and repair muscles. Currently, measuring muscle protein use usually involves a procedure called a muscle biopsy, which takes a small piece of muscle tissue. This study is testing a different technique, called indicator amino acid oxidation (IAAO), which is much simpler than a biopsy. While IAAO can tell us about overall protein use in the body, it's not yet clear if it accurately reflects what's happening specifically in our muscles. By comparing IAAO to the traditional muscle biopsy method, researchers hope to confirm if this simpler test can give reliable information about muscle protein building. This could make future research into muscle health and nutrition much easier and less uncomfortable for participants.

At a glance

Status

Recruiting

Phase

Sponsor

University of Toronto

Enrolment target

Start

01 Dec 2025

Estimated completion

20 May 2026

Protein Metabolism

What is this study about?

When we eat protein, our bodies break it down and use the building blocks (called amino acids) to create and repair tissues, especially muscles. Understanding how effectively our bodies turn dietary protein into new muscle is really important for health, fitness, and recovery. Currently, the most accurate way to measure this muscle-building process involves taking a small sample of muscle tissue (a "biopsy") and using special markers called stable isotopes. This method is very precise, but it can be uncomfortable and has some minor risks, making it difficult for many people to participate in such studies.

This study is exploring a different, less invasive method called the "indicator amino acid oxidation" (IAAO) technique. Instead of a biopsy, this method typically involves drinking a special beverage with a harmless tracer. It works by measuring how the body processes certain amino acids, giving an idea of overall protein use. Researchers want to find out if this simpler IAAO technique, which looks at whole-body protein processing, can accurately reflect what's happening specifically in our muscles, which is usually measured with the more invasive biopsy method.

If the IAAO technique proves to be accurate for understanding muscle protein building, it would be a big step forward. It would mean that future studies on how protein affects our muscles could be done without needing frequent muscle biopsies. This would make it much easier for people to take part in research, lead to more studies on this important topic, and help us gain a better understanding of how nutrition impacts muscle health in a way that's much more comfortable for volunteers.

Key takeaways

This study aims to find a simpler way to measure muscle protein use.
It compares a new, less invasive technique (IAAO) with traditional methods.
Better measurement tools could make future research on muscle health easier.
Participants must be healthy adults aged 18-35 within a healthy weight range.
You cannot participate if you have certain allergies or use hormonal contraception.
The study involves consuming a special protein drink with a harmless tracer.

Who may be eligible?

This study is looking for healthy adults between 18 and 35 years old. To make sure the results are clear, participants need to be within a healthy weight range (BMI between 18.5 and 24.9) and have a healthy waist-to-hip ratio. For female participants, it's important to have a regular menstrual cycle.

You also need to be reasonably active, as measured by a specific exercise questionnaire. Most importantly, you must be willing to follow all the study instructions, including avoiding intense physical activity for two days before certain study sessions.

However, you cannot take part if you have allergies to common local anaesthetics like lidocaine, if you regularly use tobacco or illegal drugs (including certain performance-enhancing drugs), or if you are currently using hormonal contraception (like the pill or implant). Also, if you can't commit to following the study rules, you won't be able to participate.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 35 years old?
Do you have a healthy weight and waist size?
Are you willing to follow all study instructions, including avoiding intense exercise before sessions?
For women: Do you have a regular menstrual cycle?
Are you physically active at least a few times a week?
Do you NOT use tobacco or illegal drugs, and are you NOT on hormonal contraception?

Answer every question to see your result.

What does participation involve?

The detailed description of what taking part involves is not provided in this summary. However, based on the information, you would likely be asked to consume a special protein drink that contains a harmless tracer. The study aims to compare a less invasive method with a more traditional one, which typically involves muscle biopsies. You'd need to follow specific rules about your physical activity, especially avoiding strenuous exercise for 48 hours before one of the study sessions. The total duration of the study and the number of visits are not specified here, but research of this type often involves several visits over a period of days or weeks.

Potential risks and benefits

Taking part in this study could help advance our understanding of muscle health and nutrition, potentially leading to easier ways to conduct future research. This benefits everyone by improving our knowledge of how diet affects our bodies. As with any medical study, there are potential risks, though they are usually small. For example, if traditional methods like muscle biopsies are used, there are minor risks associated with the biopsy procedure itself, such as bruising or discomfort. If you have an allergy to local anaesthetics, you would be excluded from participating. You are free to withdraw from the study at any time without giving a reason, and it will not affect your usual medical care.

Locations (1)

Kinesiology & Physical Education
Verified postcode
Toronto, Canada· Recruiting

Common questions

What is the main goal of this study?

The study wants to see if a simpler test can accurately measure how our muscles use protein, compared to more invasive methods.

What is a 'stable isotope tracer beverage'?

It's a harmless drink containing special ingredients that help researchers track how your body uses protein without being radioactive or dangerous.

Will I have to have a muscle biopsy?

The information provided suggests comparing a new method to a 'gold-standard' method which often involves muscle biopsies. You should ask the study team for exact details on what procedures you might have.

Who can't join this study?

People with allergies to certain anaesthetics, those using hormonal contraception, or who use tobacco/illegal drugs, cannot participate.

What does 'IAAO' mean?

IAAO stands for 'indicator amino acid oxidation', which is a scientific technique to measure how the body uses protein based on how it processes certain amino acids.

How to find out more

Sabrina T Barsky, Ph.D.

sabrina.barsky@utoronto.ca 16475400115 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.