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Every autumn the American College of Sports Medicine (ACSM) asks fitness professionals which trends will shape the coming year. The 2027 results came out on October 20, 2026. Like every edition, it measures expected popularity rather than effectiveness. Here is what they say, where HIIT landed, and what it all means if the Norwegian 4x4 is part of your week. For the backstory and the full 2026 list, read our 2026 year in review.
ACSM's top 10 fitness trends for 2027
The top fitness trends for 2027, according to ACSM's survey of more than 1,400 fitness professionals, are:
- Wearable technology
- Mobile exercise apps
- Balance, flow and core strength
- Fitness programs for older adults
- Traditional strength training
- Exercise for weight management
- Group fitness classes
- Data-driven training technology
- Exercise for mental health and well-being
- Influencer- and ambassador-led fitness programs
| Trend | 2027 rank | Change vs 2026 |
|---|---|---|
| Wearable technology | 1 | No change (10th time at No. 1) |
| Mobile exercise apps | 2 | Up 2 |
| Balance, flow and core strength | 3 | Up 2 |
| Fitness programs for older adults | 4 | Down 2 (top 5 for 5th straight year) |
| Traditional strength training | 5 | Up 2 |
| Exercise for weight management | 6 | Down 3 |
| Group fitness classes | 7 | Up 6 |
| Data-driven training technology | 8 | No change |
| Exercise for mental health and well-being | 9 | Down 3 |
| Influencer-led programs | 10 | Back from outside the top 20 |
| High-intensity interval training | 12 | No change |
Where HIIT landed: steady at No. 12
HIIT held at No. 12, the same spot as 2026 and well below its No. 6 ranking in 2025. It ranked No. 1 in both 2014 and 2018. Read this as a category that has matured rather than one that is fading. Coaches no longer treat "do some HIIT" as a new idea, and interest has moved toward specific protocols.
Remember what the ranking measures: ACSM surveys professionals about what they expect to be popular, not about what is effective. A trend can fall while the evidence for it stays strong, and the 4x4 is a good example.
Why generic HIIT stalled while the 4x4 grew
This is our reading of the last two years, not an ACSM finding:
- People want a measurable outcome. With wearables at No. 1 and data-driven training at No. 8, people expect a workout to move a number. The 4x4 has a clear target: VO₂ max.
- A name beats a category. "HIIT" covers everything from Tabata to bootcamp burpees. "Norwegian 4x4" is one specific session with fixed intervals and a research group behind it.
- It fits the longevity story. VO₂ max is now widely discussed as a health marker, and the 4x4 is the classic way to train it. See our Attia longevity page.
Seven shifts that will shape the 4x4 in 2027
1. Your watch will run the session
Wearables (No. 1) and data-driven training technology (No. 8) point the same way: heart-rate-guided intervals that tell you to push or ease off in real time. Know the limits of wrist-based estimates first; see our VO₂ max accuracy guide.
2. Apps are climbing back
Mobile exercise apps rose to No. 2. Structured programs with timers, zones and progress logs give a protocol like the 4x4 a clear advantage over freestyle workouts. Our fitness apps overview compares the options.
3. Strength plus intervals becomes the standard week
Traditional strength training rose two places to No. 5. Expect more hybrid weeks: two strength days, one or two 4x4 sessions, and easy Zone 2 cardio. Our muscle and intervals guide shows how to combine them without overloading recovery.
4. Older adults stay a priority
Programs for older adults have been top five for five straight years. The NTNU-led Generation 100 trial made the 4x4 one of the few HIIT protocols tested at scale in people aged 70–77. Start with our HIIT after 50 guide.
5. Exercise is prescribed alongside GLP-1s
Exercise for weight management sits at No. 6, down from No. 3 in 2026, and ACSM ties it to the wider use of obesity medications. The standard advice: resistance training and protein to keep muscle, plus cardio for heart health. See preventing muscle loss on GLP-1s.
6. Intervals go social
Group fitness classes jumped six places to No. 7, influencer-led programs returned at No. 10, and ACSM added competitive fitness events such as HYROX to the survey for the first time. Expect more 4x4 group classes and race-prep blocks. Our HYROX beginner plan shows one approach.
7. Balance and mobility move up
Balance, flow and core strength climbed to No. 3. That makes a short mobility block a sensible add-on before or after interval days, especially for older trainees.
Trends to treat with caution
Rankings reward visibility. Before changing your training for a trend, ask three questions: Is there a controlled trial behind it? Does it measure something that matters to you? Can you sustain it for 12 weeks? The 4x4 passes all three. Many viral workouts pass none.
How to use this in January
The trends point to one practical plan: a structured, heart-rate-guided 4x4 block, paired with strength and easy cardio, measured by your VO₂ max before and after. That is exactly what our 12-week Norwegian 4x4 plan for 2027 lays out. Set your zones first with the heart rate calculator.
Frequently Asked Questions
What is the top fitness trend for 2027?
Wearable technology. It is No. 1 in ACSM's 2027 Worldwide Fitness Trends survey, its 10th time at the top, followed by mobile exercise apps and balance, flow and core strength.
Where does HIIT rank in 2027?
No. 12, unchanged from 2026 and down from No. 6 in 2025. HIIT has settled into a steady staple rather than a rising trend.
Is the Norwegian 4x4 still worth doing in 2027?
Yes. Trend rankings measure what fitness professionals expect to be popular, not what works. The 4x4 remains one of the best-studied ways to raise VO₂ max, and it fits the 2027 trends toward wearables, data-driven training and older adults.
How was the ACSM 2027 survey done?
ACSM surveyed more than 1,400 fitness professionals and published the results in ACSM's Health & Fitness Journal on October 20, 2026.
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