Brief Summary

High-intensity functional training (HIFT), a new version of high-intensity interval training, has gained interest in recent years. HIFT is based on the CrossFit training template and includes multijoint movement patterns via both endurance and strengthening exercises. Research has shown positive effects of HIFT on body composition, cardiorespiratory fitness, and muscle performance of young individuals. The effectiveness of HIFT in higher ages and its protein requirements are less well documented. Protein requirements have been widely investigated in resistance training, where it has been found that protein supplementation may have additive beneficial effects on muscle strength and lean body mass. However, there is a research gap regarding the adaptations to HIFT when combined with protein supplementation. Thus, the aim of this research is to compare the effects of egg white supplementation, whey protein supplementation (as a positive comparator), and maltodextrin (a carbohydrate as placebo) on body composition, physical performance, and plasma amino acid profile in young and middle-aged trained individuals of both sexes who perform HIFT. Participants will take all three supplements for 6 weeks each, with 2 weeks of washout (no supplementation) in between, in random and counterbalanced order. Researchers will not know the supplementation status of the participants. Participants will receive 0.6 g of protein or placebo per kg body weight daily on top of isoenergetic dietary plans to avoid differences in energy intake that might compromise the validity of the study. The dietary plans will be individualized and will provided 1.0 g protein/kg body weight/day. The HIFT protocol will include multimodal patterns of movement, combining endurance and strengthening exercises with the use of equipment such as Total Resistance eXercise (TRX), Bosu, kettlebells, and barbells. Participants will undergo measurements of muscle strength, muscle endurance, aerobic capacity, and body composition at the beginning and end of the study, as well as during the two washout periods. Also, plasma amino acids, hematology, biochemistry, and hormones will be measured. Comparison of all these outcome measures between supplements will reveal whether protein supplementation is useful in HIFT.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at P25-P50 for not_applicable

Timeline

Completed

Started Nov 2021

Typical duration for not_applicable

Geographic Reach

1 country

1 active site

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

1.9 years study duration

Study Start

First participant enrolled

November 1, 2021

Completed

6 months until next milestone

First Submitted

Initial submission to the registry

April 26, 2022

Completed

1 month until next milestone

First Posted

Study publicly available on registry

May 31, 2022

Completed

10 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 31, 2023

Completed

6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

September 30, 2023

Completed

Last Updated

October 5, 2023

Status Verified

October 1, 2023

Enrollment Period

1.4 years

First QC Date

April 26, 2022

Last Update Submit

October 3, 2023

Conditions

Exercise Training Dietary Supplements

Outcome Measures

Primary Outcomes (12)

Lean and fat mass pre-supplementation
Lean and fat mass of the whole body and its parts (trunk, legs and arms) will be assessed by dual X-ray absorptiometry.
Within 2 weeks before the beginning of supplementation.
Lean and fat mass post-supplementation
Lean and fat mass of the whole body and its parts (trunk, legs and arms) will be assessed by dual X-ray absorptiometry.
Within 2 weeks after the end of supplementation.
Maximal dynamic strength of shoulder muscles pre-supplementation
Maximal dynamic strength of shoulder muscles will be assessed by measurement of one-repetition maximum.
Within 2 weeks before the beginning of supplementation.
Maximal dynamic strength of shoulder muscles post-supplementation
Maximal dynamic strength of shoulder muscles will be assessed by measurement of one-repetition maximum.
Within 2 weeks after the end of supplementation.
Force-velocity relationship of knee flexors and extensors pre-supplementation
Force-velocity relationship of knee flexors and extensors will be assessed in isokinetic dynamometer.
Within 2 weeks before the beginning of supplementation.
Force-velocity relationship of knee flexors and extensors post-supplementation
Force-velocity relationship of knee flexors and extensors will be assessed in isokinetic dynamometer.
Within 2 weeks after the end of supplementation.
Plasma amino acid profile pre-supplementation
Plasma amino acid profile (that is, the concentration of each individual amino acid) will be determined by liquid chromatography - mass spectrometry.
Within 4 days before the beginning of supplementation.
Plasma amino acid profile post-supplementation
Plasma amino acid profile (that is, the concentration of each individual amino acid) will be determined by liquid chromatography - mass spectrometry.
Within 4 days after the end of supplementation.
Aerobic fitness pre-supplementation
Aerobic fitness will be assessed by measurement of maximal oxygen uptake through a maximal graded exercise test on treadmill.
Within 2 weeks before the beginning of supplementation.
Aerobic fitness post-supplementation
Aerobic fitness will be assessed by measurement of maximal oxygen uptake through a maximal graded exercise test on treadmill.
Within 2 weeks after the end of supplementation.
Muscle endurance pre-supplementation
Muscle endurance will be assessed by performing multiple sit-ups, knee flexions and knee extensions.
Within 2 weeks before the beginning of supplementation.
Muscle endurance post-supplementation
Muscle endurance will be assessed by performing multiple sit-ups, knee flexions and knee extensions.
Within 2 weeks after the end of supplementation.

Secondary Outcomes (16)

Biochemical analyses pre-supplementation
Within 4 days before the beginning of supplementation.
Biochemical analyses post-supplementation
Within 4 days after the end of supplementation.
Hormonal analyses pre-supplementation
Within 4 days before the end of supplementation.
Hormonal analyses post-supplementation
Within 4 days after the end of supplementation.
Resting metabolic rate pre-supplementation
Within 2 weeks before the beginning of supplementation.
+11 more secondary outcomes