Precision High-Intensity Training Through Epigenetics (PHITE) (PHITE)
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT03380923 |
Recruitment Status :
Recruiting
First Posted : December 21, 2017
Last Update Posted : June 18, 2020
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
The PHITE collaborative team, consisting of Tim Broderick, MD (Overall PI), Wright State University (WSU); Marcas Bamman, PhD (Site PI), The University of Alabama at Birmingham (UAB); and Ron Evans, PhD and Joe Ecker, PhD, Salk Institute for Biological Studies, are working with funding from the US Department of Defense (DoD), Office of Naval Research (ONR), to explore the link between physical training and epigenetics. This is a key interest area for the DoD ONR because it provides high-impact optimization of force readiness in warfighters with diverse backgrounds.
The term epigenetics refers to heritable changes in gene expression (active versus inactive genes) that does not involve changes to the underlying DNA sequence; a change in phenotype (the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment) without a change in genotype (the genetic constitution of an individual organism) . This in turn affects how cells read the genes. Epigenetic change is a regular and natural occurrence but can also be influenced by several factors including age, the environment/lifestyle, and disease state. Epigenetic modifications can manifest as commonly as the manner in which cells terminally differentiate to end up as skin cells, liver cells, brain cells, etc. New and ongoing research is continuously uncovering the role of epigenetics in a variety of human conditions. This study is designed to assess whether epigenetics is a primary mechanism modulating how individuals adapt to specific exercise training prescriptions designed to produce a warfighter phenotype.
The PHITE team is organized around a shared test population of human subjects for which UAB will oversee recruitment, training, testing, and sampling. Healthy but untrained volunteers, both men and women, 18-27 y of age-phenotypical of the US warfighter-will participate in a 12-wk, two-arm, single-blind, randomized, exercise dose-response trial comparing two intensities of combined training: Moderate-Intensity vs. High-Intensity. Biospecimens are collected before and after an acute exercise bout in the pre-training state, and again after 12 weeks of 3 d/wk combined exercise training. Numerous phenotyping assessments are collected before after the 12-week intervention period to associate exercise training outcomes with molecular changes in the skeletal muscle and blood biospecimens.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Healthy | Behavioral: Moderate Intensity Behavioral: High Intensity | Not Applicable |

Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 150 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Randomized to moderate intensity vs. high-intensity exercise training prescription. |
Masking: | Double (Investigator, Outcomes Assessor) |
Masking Description: | Outcomes assessors analyzing biospecimen samples are blinded to the arm to which each participant has been randomly assigned when doing analysis. Investigators are blinded to each participant's randomized assignment. |
Primary Purpose: | Basic Science |
Official Title: | Precision High-Intensity Training Through Epigenetics (PHITE) |
Actual Study Start Date : | February 23, 2017 |
Estimated Primary Completion Date : | April 30, 2021 |
Estimated Study Completion Date : | August 31, 2021 |
Arm | Intervention/treatment |
---|---|
Experimental: Moderate Intensity (MOD)
Endurance Training (ET): 3 d/wk x 30 minutes (min) of steady-state, moderate-intensity exercise on a treadmill or stationary cycle ergometer at target heart rate (HR) = 65-75% of maximum oxygen consumption rate (VO2max). The two modes (treadmill, bicycle) are offered for variety, and each subject is required to use each mode at least 1 d/wk to prevent bias. Resistance training (RT): 2 d/wk consisting of a prescription engaging all major muscle groups in 10 movements. Excluding abdominal crunches, target intensity is 12 repetitions/set to volitional fatigue. Subjects complete 3 sets of each movement, with ~60 seconds (s) rest between sets. For each movement, resistance increases when 14 repetitions are achieved for 2 of 3 sets. HR is monitored throughout each session and stored for analysis. |
Behavioral: Moderate Intensity
Exercise prescription intensity is moderate
Other Name: MOD |
Experimental: High Intensity (HI)
RT: The 2 d/wk RT prescription differs from the MOD arm only in intensity and rest intervals. The same approach to progression applies, but HI RT intensity targets 8-10 repetitions per set; thus, resistance loads increase when 10 repetitions are achieved for 2 of 3 sets. The HI arm performs "superset" training, pairing movements stressing different muscle groups, with only 30-45 s between. ET: In lieu of steady-state endurance exercise, the HI arm performs high-intensity interval training (HIIT) 3 d/wk using a mix of challenging, explosive movements at maximal intensity. 10 x 30 s maximal intensity intervals are separated by 30 s rest intervals. HR is monitored throughout each session and stored for analysis. |
Behavioral: High Intensity
Exercise prescription intensity is high
Other Name: HI |
- Change in muscle mass [ Time Frame: 16 weeks ]Muscle mass is assessed using DXA (dual-energy X-ray absorptiometry)
- Change in cardiorespiratory fitness (VO2max) [ Time Frame: 16 weeks ]VO2max is assessed using via indirect calorimetry during a graded cycle ergometry protocol

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 27 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
-Healthy 18-27 year olds who are not in the US armed forces
Exclusion Criteria:
- History of regular endurance or resistance training in past 12 months
- BMI>30
- Inability to tolerate intense exercise
- Diabetes
- Uncontrolled hypertension
- Unstable or exercise induced angina pectoris or myocardial ischemia
- Vascular disease
- Neurologic disease
- Musculoskeletal disorder
- Mental health disorder
- Any chronic or infectious disease that would preclude full participation
- Lidocaine allergy
- Pregnancy

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03380923
Contact: Craig Tuggle, MA | 205-934-6221 | tugg12@uab.edu | |
Contact: Billy Tingle, BSN | 205-934-3706 | billy@uab.edu |
United States, Alabama | |
University of Alabama Center for Exercise Medicine | Recruiting |
Birmingham, Alabama, United States, 35205 | |
Contact: Craig Tuggle, MA 205-934-6221 tugg12@uab.edu | |
Contact: Billy Tingle, BSN 205-934-3706 billy@uab.edu | |
Principal Investigator: Marcas Bamman, PhD |
Principal Investigator: | Marcas Bamman, PhD | University of Alabama at Birmingham |
Responsible Party: | Marcas M. Bamman, PhD, Site Principle Investigator, University of Alabama at Birmingham |
ClinicalTrials.gov Identifier: | NCT03380923 |
Other Study ID Numbers: |
N000141613159 |
First Posted: | December 21, 2017 Key Record Dates |
Last Update Posted: | June 18, 2020 |
Last Verified: | June 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | De-identified data will be available 12 months after completion of the trial. Data will be publicly available indefinitely. Data will include phenotyping test results and molecular mapping results. |
Supporting Materials: |
Study Protocol |
Time Frame: | De-identified data will be available 12 months after completion of the trial. Data will be publicly available indefinitely. |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
epigenetics exercise dose-response inter-individual response heterogeneity exercise training adaptations |