ClinicalTrials.gg
CompletedNCT07824830CFIT-IMMUNEUpdated Sep 17, 2026

Effects of CrossFit Training on the Immune System

An interventional study of CrossFit Training Program in Immune Function Sedentary Lifestyle, sponsored by Inonu University. Completed at 1 site in Turkey (Türkiye). Open to male participants aged 19 Years to 24 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-17.

Sponsored by Inonu University · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
30
Allocation
Not applicable
Ages
19 Years to 24 Years
Sex
Male
01

Study summary

This interventional study aims to investigate the effects of both acute and eight-week CrossFit training on immune system responses in sedentary adults. Participants will undergo an acute CrossFit exercise session, followed by an eight-week supervised CrossFit training program. Blood samples will be collected before and after the acute exercise session and again following the eight-week intervention to evaluate changes in selected immune system biomarkers. The primary objective is to determine whether acute and chronic CrossFit training induces significant alterations in immune function in previously sedentary individuals. The findings are expected to contribute to a better understanding of the immunological adaptations associated with high-intensity functional training and to provide evidence regarding the safety and potential health benefits of CrossFit exercise in sedentary populations.

Read the detailed description

CrossFit is a high-intensity functional training (HIFT) program that combines aerobic exercise, resistance training, weightlifting, gymnastics, and metabolic conditioning within a single exercise session. Owing to its increasing popularity among both athletes and the general population, there is growing interest in understanding the physiological and immunological adaptations associated with CrossFit training. Although regular physical activity is known to enhance immune function and improve overall health, high-intensity exercise may induce transient alterations in immune responses, particularly in previously sedentary individuals.

The immune system plays a critical role in protecting the body against infections and maintaining physiological homeostasis. Acute bouts of strenuous exercise may temporarily modify immune cell function and inflammatory responses, whereas long-term exercise training may promote beneficial adaptations and improve immune regulation. However, the effects of CrossFit training on immune system biomarkers in sedentary adults remain insufficiently investigated.

The purpose of this interventional study is to evaluate the effects of both an acute CrossFit exercise session and an eight-week supervised CrossFit training program on immune system responses in sedentary adults. Participants will complete baseline assessments followed by an acute CrossFit exercise session. Subsequently, they will participate in an eight-week supervised CrossFit training program. Blood samples will be collected at predetermined time points before and after the acute exercise session and following completion of the eight-week intervention to assess changes in immune system biomarkers.

The primary objective is to determine whether acute and chronic CrossFit training produce significant changes in immune function in sedentary individuals. The results of this study are expected to improve understanding of the immunological responses to high-intensity functional training and provide evidence regarding the safety and potential health benefits of CrossFit exercise for previously sedentary adults.

02

Conditions studied

  • Immune Function Sedentary Lifestyle

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Keywords

  • CrossFit
  • Immune System
  • Acute Exercise
  • Chronic Exercise
03

In context

Sedentary Behavior

1,273 studies on the registry are indexed under Sedentary Behavior; 300 are open to participants now.

This study's enrollment of 30 is below the median of 60 across 1,076 interventional studies indexed under Sedentary Behavior.

Browse Sedentary Behavior studies →

Lead sponsor

Inonu University is the lead sponsor of 394 studies on the registry; 95 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
19 Years to 24 Years
Sexes eligible
Male
Accepts healthy volunteers
Yes

Eligibility criteria

Inclusion Criteria:- Male participants aged 18 to 23 years

  • Currently enrolled as a student at Yalova University
  • Not regularly participating in exercise or sports training
  • Medically eligible to participate in CrossFit training
  • Willing and able to complete the eight-week CrossFit training program conducted three days per week
  • Willing to provide venous blood samples at the specified assessment times
  • Willing to provide written

Exclusion Criteria:- Regular participation in exercise or sports training

  • History of a neurological disorder within the previous year
  • History of an auditory, visual, or vestibular disorder within the previous year
  • Serious upper- or lower-extremity injury within the previous six months
  • Presence of a medical condition that could prevent safe participation in the exercise program
  • Inability to complete the training or blood-sampling procedures
  • Withdrawal of voluntary consent
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
30 participants (actual)

Study arms

  • Experimental
    CrossFit Training

    Participants assigned to the CrossFit Training Group will participate in a structured CrossFit exercise program for 8 weeks. Training sessions will be performed three times per week under the supervision of certified trainers. Each session will include warm-up, functional strength exercises, high-intensity metabolic conditioning exercises, and cool-down periods. Exercise intensity will be monitored throughout the intervention period.

    Behavioral: CrossFit Training Program

Interventions

  • BehavioralCrossFit Training Program

    articipants in the experimental group will participate in an eight-week CrossFit training program performed three days per week (Monday, Wednesday, and Friday). Each training session will last approximately 60 minutes and will include a dynamic warm-up, strength training exercises, a Workout of the Day (WOD) section, and a cool-down period. The strength training component will include functional resistance exercises such as squats, deadlifts, and push presses, performed for 3-5 sets of 5-10 repetitions. Training intensity will progressively increase from approximately 60-70% of one-repetition maximum (1RM) during the first four weeks to 70-80% of 1RM during the final four weeks. The WOD component will include high-intensity functional exercises such as burpees, kettlebell swings, box jumps, rowing, sit-ups, pull-ups, and short-distance running. WOD sessions will be performed using AMRAP (As Many Rounds As Possible) and For Time formats with durations of approximately 10-20 minutes. P

    Also known as: 8-Week CrossFit Training Program

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What researchers measure

Primary outcomes

  1. Mean Change in Total Leukocyte Count From Baseline to Completion of the Eight-Week CrossFit Program

    Total leukocyte count will be determined from venous blood samples collected before the first training session and immediately after completion of the eight-week CrossFit training program. For each participant, the change will be calculated as the post-program value minus the baseline value. The group-level outcome will be summarized using the mean change and standard deviation.

    Time frame: Baseline and immediately after completion of the eight-week CrossFit training program

  2. Mean Change in Absolute Monocyte Count From Baseline to Completion of the Eight-Week CrossFit Program

    Absolute monocyte count will be determined from venous blood samples collected before the first training session and immediately after completion of the eight-week CrossFit training program. For each participant, the change will be calculated as the post-program value minus the baseline value. The group-level outcome will be summarized using the mean change and standard deviation.

    Time frame: Baseline and immediately after completion of the eight-week CrossFit training program

  3. Mean Change in Absolute Lymphocyte Count From Baseline to Completion of the Eight-Week CrossFit Program

    Absolute lymphocyte count will be determined from venous blood samples collected before the first training session and immediately after completion of the eight-week CrossFit training program. For each participant, the change will be calculated as the post-program value minus the baseline value. The group-level outcome will be summarized using the mean change and standard deviation.

    Time frame: Baseline and immediately after completion of the eight-week CrossFit training program

  4. Mean Change in Absolute Neutrophil Count From Baseline to Completion of the Eight-Week CrossFit Program

    Absolute neutrophil count will be determined from venous blood samples collected before the first training session and immediately after completion of the eight-week CrossFit training program. For each participant, the change will be calculated as the post-program value minus the baseline value. The group-level outcome will be summarized using the mean change and standard deviation.

    Time frame: Baseline and immediately after completion of the eight-week CrossFit training program

07

Study locations

1 site
  • Exercise Physiology Laboratory, Faculty of Sport Sciences, Karabuk University
    Karabük, Karabük Province, Turkey (Türkiye)
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Ran from May 2026 to primary completion in Jun 2026, 1 month.

Of 733 non-industry interventional studies with no phase under Sedentary Behavior, half reached primary completion within 14 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 31. This study's 1 month is below that.

Counting every sponsor, half of 741 studies reached it within 14 months; a quarter within 6 and three quarters within 31.

How these figures are worked out, and which studies are left out of them.

Registered
Jul 28, 2026
First posted
Sep 17, 2026
StartActual
May 5, 2026
Primary completionActual
Jun 30, 2026
CompletionActual
Jun 30, 2026
Last update
Sep 17, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Sep 17, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07824830
Lead sponsor
Inonu University
Responsible party
Assoc. Prof. Dr. Özgür EKEN (Professor, Inonu University) — Principal investigator
First posted
Sep 17, 2026
Start date
May 5, 2026
Primary completion
Jun 30, 2026
Completion
Jun 30, 2026
Last update
Sep 17, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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