2025 Fitness Trend Spotlight: HIIT
WASHINGTON — Have you made it to the gym in 2025? You can start any time, but in the spirit of January when many make resolutions, we’ll take another look at one of the top fitness trends for this year.
Last week, we dove into the slow and controlled Functional Fitness Training. Today, we’ll pick up the pace with the sweaty, heart-pumping, high-intensity interval training. After a quick recap of the American College of Sports Medicine trend report, we’ll tell you what you need to know about HIIT, how it works, how to try it, the pros and the cons.
The ACSM 2025 Fitness Trends
Each year since 2006, the ACSM , the largest fitness association which was founded in 1954, has announced its predictions for the top 20 fitness trends. The list is based on a survey sent to ACSM members based on scientific research and exercise science. The 2025 report was released in October 2024.
As a refresher, here are the top 10 trends for 2025:
- Wearable technology.
- Mobile exercise apps.
- Fitness for older adults.
- Exercise for weight loss.
- Traditional strength training.
- High-intensity interval training.
- Data-driven training technology.
- Exercise for mental health.
- Functional fitness training.
- Health/wellness coaching.
This week, we’re focusing on number six: HIIT.
Breaking Down High-Intensity Interval Training
The ACSM defines HIIT as “repeated bouts of high-intensity effort followed by varied recovery times.” You spend a short period, anywhere from five seconds to eight minutes, working almost as hard as possible. Then you significantly reduce the intensity or take a complete rest for either as long as the work period or longer.
You alternate the two for 10 to 60 minutes to complete the HIIT workout. The ACSM notes that you should work at 80 to 95% of your maximum heart rate and recover at 40 to 50%.
Over time, spiking your heart rate, letting it recover, and spiking it again can help improve heart rate recovery, a predictor of cardiovascular health.
The formula for HIIT matters most; any type of exercise you plug into the time frames and intensity levels will work. The shorter the time you spend working, the higher the intensity should be. There are two primary types of exercise you’ll find in an HIIT workout:
- Strength Exercises: Strength exercises are often done slowly but may be sped up in an HIIT workout. Circuit training, which involves moving from one exercise to the next without resting, may include strength exercises like squats and push-ups.
- Cardio Exercises: You can do HIIT with cardio exercises (on or off a machine), like running, cycling, swimming, stair-climbing, or rowing.
- Combination: Advanced workouts like CrossFit tend to combine strength and cardio exercises, like pairing deadlifts with going as fast as possible on a rowing machine.
Types of HIIT
Under the umbrella of HIIT, you’ll see several other types of workouts that use the formula. Technically, you must work as hard as possible during work periods for proper HIIT. Some of these workouts don’t reach that level, so they’re more suitable for beginners.
- Interval Training: This approach is more beginner-friendly. You alternate higher and lower intensities, but it doesn’t have to be your maximum effort. For example, you could go on a longer run, spend five minutes going moderately fast, five minutes at a slower jog and alternate the two speeds.
- Tabata Training: The Tabata protocol is specific: 20 seconds of your highest effort, 10 seconds of complete rest, repeat for eight rounds, lasting four minutes total. A full Tabata workout may have two or three of these four-minute blasts.
- Sprint Workouts: Sprint interval training means the work period is “all-out,” as fast and hard as possible. In a running workout, this may be a 10-second sprint followed by complete rest.
- Group Fitness Classes: Group fitness classes may include any of the above styles of HIIT and may use strength, cardio, or both types of exercises. Many popular gym chains offer their own style of HIIT classes. CrossFit tends to be the most challenging of the bunch since they may pair advanced exercises like Olympic lifting with all-out sprints.
Benefits of HIIT
- Improves Heart Health: Under the CDC’s physical activity guidelines for cardiovascular health, doing HIIT qualifies as vigorous-intensity exercise, and they recommend 75 minutes per week.
- Heart Rate Recovery: Improving heart rate recovery benefits heart health. It also can boost endurance and athletic performance.
- Time Efficient: You can complete an HIIT workout in 15 to 20 minutes.
- Mental Health: Recent research suggests HIIT can help improve mental health, reducing symptoms of anxiety and depression.
Risks of HIIT
- Harder Recovery: Because HIIT is so intense, it can take your body (muscles and heart) longer to recover.
- Injury Risk: Many HIIT workouts require you to move quickly to raise your heart rate. Exercising at a high speed can increase the risk of injury, especially for beginners. Be sure to learn proper form by going slowly first.
- Can Be High-Impact: HIIT classes often involve jumping and running, high-impact activities that raise your heart rate. However, high-impact exercise can be tough on joints for people with injuries, medical conditions and older adults.
- Intense for Beginners: Aside from the movements, the heart rate spike may also be too much for newbies. It’s best to start with an interval workout that doesn’t push you to your maximum.
High Risk, High Reward
The primary risk of HIIT as a popular exercise for newbies in January is that it is incredibly intense for beginners. The exercises, the speed, and the heart rate spikes are all great for your health in the long run, but it’s always best to scale up slowly. Though trying that HIIT class to kickstart your gym journey may be tempting, here’s a safety tip for beginners.
Moving slowly, with control, and engaging your muscles while performing low-impact squats will quickly raise your heart rate, and you’ll sweat before you know it. Learning to do them correctly before adding jumping squats to the mix is safer, and you’ll still feel the burn and sweat.
Our website content, services and products are for informational purposes only. The Well News does not provide medical advice, diagnosis or treatment. If you have medical concerns or questions, discuss with your health care professional.
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