Functional training: what it means, what the trials compared it with, and a first session

"Functional" gets attached to almost anything in a gym. In the research it has a narrower meaning: exercises that use several joints at once, often moving in more than one direction, combined and varied rather than done one muscle at a time. This page covers what the term means, what the trials found when they compared it with traditional training, what hasn't been tested, and a first session you can run.

What functional training is

• Multi-joint, not isolated. A 2018 paper setting out a working definition describes high-intensity functional training as emphasizing functional, multi-joint movements that can be modified to any fitness level.¹ The same idea runs through compound exercises.
• More than one plane. In Li 2025, the functional program centred on "integrated, multi-joint, multi-planar movements", against a traditional program of isolated fitness exercises.² Its exercises included Bulgarian split squats, lunges with rotation and medicine ball slams; the traditional program used sit-ups and conventional squats.²
• Not the same as HIIT. Interval training is short hard bursts with rest between; high-intensity functional training uses constantly varied functional exercises over different durations, with or without rest.¹ The HIIT workout covers intervals.

What the trials found, at a glance

Where functional training came out ahead

• Against a traditional PE program. In Li 2025, male university students who weren't athletes, average age about 19, were randomized to functional training or a traditional program of matched length and frequency for 8 weeks. The paper's numbers don't agree: the abstract gives 35 students in total but 20 per group, the methods allocate 40 at 20 a group, and another passage puts 15 in the traditional group. The functional group improved more on a seven-part movement screen, and on all five fitness tests: a 50 m sprint, a 1,000 m run, sit-and-reach, standing long jump and vital capacity.²
• Aerobic fitness against resistance training. In Hosseini Moshkenani 2026, 34 men with overweight, average age about 32, were assigned to high-intensity functional training (13 men; four sets of 30-second exercises at 30% of 1RM), resistance training (10 men; three sets of 12 at 70% of 1RM) or no training (11 men), three times a week for 8 weeks. Functional training raised VO₂max significantly more than resistance training and the control group.³
• Against doing nothing. Wilke 2020 pooled 17 papers in healthy people. Against no exercise, high-intensity functional training had small to moderate positive effects on endurance and on strength, but none on balance.⁵

Where traditional training held its own

• Strength. In Hosseini Moshkenani 2026, both groups increased their one-rep max on the bench press.³ Resistance training also raised VO₂max against the control group.³
• Agility, in young athletes. In Gao 2025, 52 boys aged about 13 with at least two years of volleyball training were randomized 26 and 26 to functional strength training or traditional resistance training, three 90-minute sessions a week for 12 weeks. Only the functional group improved its standing and approach reach height; only the traditional group significantly improved an agility test. Between the groups, no outcome differed significantly.⁴
• Endurance. In Wilke 2020, high-intensity functional training was about as effective for endurance as moderate-intensity endurance training and as interval training.⁵

What hasn't been tested

Wilke 2020 found no study comparing high-intensity functional training with classic resistance training or balance training, and wrote that the evidence doesn't allow that comparison.⁵ The two later trials above against resistance training, Gao 2025 and Hosseini Moshkenani 2026, are small, last 8 to 12 weeks, and studied boys and men with overweight; Li 2025 studied young men against a PE program. So "functional training beats weights" isn't something the research shows yet; "it improved fitness tests and held its own" is.

A first functional session

As a practical session, not one a study tested:

Move from one exercise to the next with little rest, then rest about two minutes between rounds. Pick weights you could lift a few more times than the reps asked. If you have pain, an injury or a medical condition, stop and ask a doctor or a physical therapist.

Common questions

Is functional training better than weight training?

Not shown either way. The one meta-analysis found no trial comparing them up to 2020,⁵ and in the two later trials above against resistance training, the groups didn't differ in young volleyball players and both gained bench-press strength in men with overweight, where functional training also raised VO₂max more.^4,3

What are functional training exercises?

Multi-joint movements, often with a turn, a single leg or a throw: split squats, lunges with rotation and medicine ball slams were the examples in Li 2025.² The session above uses the same idea with a kettlebell and dumbbells.

Can functional training replace lifting?

For general fitness it held its own in the trials above. If your goal is a heavier squat, bench or deadlift, no study here tested functional training for that; as a practical point, practising the lift is the direct route. The full-body workout plan mixes both.

If you'd rather have the week planned

Functional or traditional is a smaller question than how the sessions fit the days you have. Coaching is the version where your workouts live in Trainerize, built around the days you actually have, and a weekly call looks at the week you just had and rebuilds the next one. Coaching for beginners explains how that works, and here's how to apply. Otherwise: run the session above once this week, beside your usual training.