Substrate Metabolism Laboratory

“The Substrate Metabolism Laboratory conducts research centered around diet and exercise, attempting to discover how these factors affect the risk and prevalence of metabolic diseases such as Type 2 diabetes. The health benefits for exercising are well-known, but what is still unclear are the actual mechanisms of diet and exercise that produce healthier lives. By studying and understanding these mechanisms, we will be able to target specific training programs or medications designed to reduce the risk of disease.”
Dr. Jeff Horowitz, Director and Professor of Movement Science

Substrate Metabolism Laboratory


CCRB 1210
401 Washtenaw Ave.
Ann Arbor, MI 48109-2214
(734) 647-3354
(734) 936-1925



High Intensity Interval Training (HIIT) Study

High Intensity Interval Training (HIIT) Study

PURPOSE: Our overall objectives are to:

  1. Assess mechanisms underlying HIIT-induced improvements in insulin resistance at the whole-body, tissue, and cellular levels; 
  2. Systematically compare different HIIT regimens to help identify effective “doses” of HIIT that may be optimal for improving metabolic health in obese adults; and
  3. Assess the ability/willingness of obese subjects to adhere to a long-term HIIT program.

Findings from these studies will greatly expand our understanding about the effects of HIIT on metabolic health, and will provide valuable information for development of programs aimed at maximizing key metabolic benefits of exercise.

To learn more about this study, and to sign up to be a potential subject for it, read the full description on the Substrate Metabolism Laboratory Studies page.

Iron and Metabolic Health Study

Iron and Metabolic Health Study

Would you like to participate in a study that would improve our understanding of the relationship between iron in the body and insulin resistance?

We are looking for men and women who are:

  • Age 18-40 years
  • Overweight or obese (classified with a Body Mass Index of 27-40 kg/m2)
  • Weight Stable (+/- 6 pounds for past 6 months)
  • Non-tobacco or e-cigarette users
  • Not taking medications or supplements known to affect metabolism or inflammation
  • Relatively healthy with no evidence/history of metabolic diseases or anemia

General blood donation eligibility requirements must be met to participate.  Individuals who have donated blood within the past 12 months will be excluded.  

Women must have regularly occurring menses and be premenopausal.  Pregnant or actively lactating women will be excluded.


Initial Screening – Before participating in the study, you will undergo a physical screening that will include a health history, a food frequency, and a physical activity questionnaire.  We will also obtain your height/weight and take a small sample of blood to measure your hemoglobin concentration. This appointment will take about 1 hour and will take place at the Substrate Metabolism Laboratory (SML) located in the Central Campus Recreation Building (CCRB) at the University of Michigan.  

If you are deemed eligible based on the results of the initial screening, you will be enrolled into our study. The study consists of four (4) distinct phases:

  1. Body Composition Assessment: We will measure your body composition using Dual Energy X-ray Absorptiometry (DEXA scan). Women will provide a urine sample for a urine pregnancy test prior to the DEXA scan.  This visit will take about 30 minutes and will take place at the Michigan Clinical Research Unit (MCRU) located in the Michigan Medicine Cardiovascular Center (CVC).
  2. Baseline Trial:  We want to assess your current level of health.  During this trial we will measure: body weight, resting blood pressure, fat metabolism, insulin sensitivity, and blood lipid profile. These tests will involve blood sampling and we will obtain a small piece of fat from your stomach. You will be required to stay in the hospital for approximately 8 hours.  At this appointment, the study team will provide you with a scale to weigh yourself at home on a daily basis.

NOTE: You will be required to maintain your weight from the baseline trial until the completion of the post-blood donation trial.  If your body weight changes ±4.5 pounds from your baseline trial weight, our research dietitian will provide strategies to help you return to the weight that you measured at your baseline trial.

  1. Blood Donation: You will donate blood about 1 week after your baseline trial at a blood donation center of your choice.  Between 24- and 72-hours following the blood donation, you will return to the SML so we can measure your hemoglobin concentration.  
  2. Post-blood Donation Trial: We will perform all of the same tests that we did at baseline testing described above in order to see how your health has changed after the blood donation.  

PARTICIPATION INCENTIVES: You will receive a total of $300 upon completion of the entire study.  You will not receive compensation for the initial screening, body composition test, or blood donation.  If you do not complete the entire study, you will be compensated at a rate of $10 for each hour spent in the hospital for the study trials.  

To sign up to screen for this study, select “Iron and Metabolic Health Study” on our general screening questionnaire.