Most of us associate high-intensity interval training, or HIIT, with the ultimate cardio shortcut.
The short bouts of maximal intensity lead to a serious fat burn, and give people who hate the slog of jogging or other steady state activities a quick, exciting way to push their cardio limits. If new research is accurate, however, HIIT can be used to help you make serious gains in the weight room, too — in half the time it takes you to finish a traditional strength training workout.
The American Council on Exercise (ACE) sponsored a study to test the effectiveness of a HIIT protocol for resistance training, and came up with some interesting results. Not only did the HIIT program lead to just as much strength gain as a more traditional — and much more time-intensive — lifting program, but in some cases, there were even greater improvements in strength.
The researchers split 48 people into three different groups — a control group, a HIIT resistance training group, and a moderate-intensity resistance (MI-RE) training group. The HIIT and the MI-RE group were put on a six-week lifting protocol, while the control group didn’t exercise over the course of the study.
To have a baseline for progress, the researchers tested the population for one-rep and five-rep max totals in 10 different exercises — back extension, biceps curl, chest press, lat pull-down, leg curl, leg extension, leg press, seated row, shoulder press, and triceps extension. The researchers re-tested all the max lifts at the end of the study to gauge the benefits of each protocol.
The HIIT lifters did one set of five reps as heavy as they possibly could of the 10 exercises either twice or three times a week. The MI-RE lifters did double the reps at less weight, and for the second half of the study, double the sets and more reps, for just as many days per week.
Importantly, the researchers noted that the MI-RE lifting program took an average of 45 minutes per session, while the HIIT lifting program, with its shorter rest periods and fewer reps, took just 20 minutes.
Both lifting groups experienced significant strength gains in both their one-rep and five-rep max numbers when the researchers tested them after the six-week period was over. However, the HIIT lifters posted more gains in four of the categories — two in just the five-rep max, and two in both the one-rep and five-rep max.
What’s more, a few of the MI-RE exercises saw no significant improvements over the first half of the study. That wasn’t the case for the HIIT protocol, which saw significant improvement in every exercise at the halfway point.
Both groups also showed similar decreases in their body-fat percentages, but the HIIT group displayed a larger decrease in both their systolic blood pressure and their low-density lipoprotein, also known as “bad,” cholesterol.
What It Means For Your Workout
If you thought that HIIT was only for cardio, you should probably think again. The study showed that the HIIT lifters made significant gains in the weight room in less than half the time of the MI-RE group — and they got even stronger in some cases, too.
So what’s this all mean for you?
For starters, you might want to consider implementing HIIT principles in your weight training when you’re looking to supercharge your gains over a short period of time. Just cut down on your reps and rest, pump up the intensity, and get ready to reap the results of your hard work.
Researchers and strength coaches already know that training plans featuring fewer reps and heavier loads are the key to increasing strength, while shorter rest periods help to initiate hypertrophy, the cellular process that builds muscle — so this new research isn’t all that shocking considering the proven science.
What you shouldn’t do is get carried away and overhaul your entire training philosophy based on the results of this one study.
There is still much more research to be done before anyone can conclusively say that HIIT is superior to more traditional weight training protocols for developing strength. This study in particular had a small sample size and limited time frame, and it wasn’t a very realistic setup to begin with, mixing exercises focused on different areas of the body rather than homing in on one area.
HIIT-style workouts should also be performed sparingly (once or twice weekly) due to their intensity, so making every single day in the gym an interval-filled sweat fest could put you on the fast track to decreased performance and injuries.
Still, the ACE study can at least serve as a good sign for guys who worry that they’ll need to spend hours in the weight room to make any gains. That’s another check in the win column for HIIT.
By Reegan Von Wildenradt