If You Had to Pick One, Should You do Strength or Cardio?

You’ve got a jam-packed day, but you’ve made it a point to carve out time to workout. So you rush over to the gym, but you only have 20 minutes. Now what do you do? The easiest option — hop on the treadmill. But is that the best option? Should you run for the short time you have?

Or would it serve you better to head to the weight rack? Which is more effective for a short workout — cardio or strength?

If you know you’re going to be pressed for time, it’s best to walk into the gym knowing what you’re going to do. “You definitely want to plan the program out ahead of time to get the most out of the limited time you have,” says Noam Tamir, a certified strength and conditioning specialist, owner and head trainer at TS Fitness in New York City. This way you won’t waste time moseying around, and before you know it, you have less than 10 minutes to work out.

Lots of people turn to cardio because it’s rather intuitive — all you have to do is step onto the treadmill and hit start, clip into the bike and pedal or sit down on the rower and start stroking. But if you’re a well-conditioned individual, steady state cardio — or running, biking or rowing at a comfortable steady pace/rate — may not be the most effective way to spend 20 minutes.

Instead, consider doing intervals, mixing sprints with recovery periods. “Doing cardio interval training would be more beneficial for caloric output and for cardiovascular fitness,” explains Tamir. “You’re not only working your endurance, but strength as well, and you’ll get more benefits of the muscular and hormonal systems.”

However, with a cardio workout, while it can be full-body if you’re rowing, doing kettlebell swings or using the VersaClimber, you aren’t putting as much external force on the body. Therefore you will achieve EPOC, or excess post-exercise oxygen consumption, which allows you to continue burning calories up to 48 hours post-workout, but it won’t be as high as a workout that puts more stress on the body, like strength or resistance.

If you’re neglecting strength training, you should rethink your approach. “Strength is so important because as we develop strength and hypertrophy, our bodies become fat-burning furnaces,” says Don Saladino, NASM, celebrity trainer and owner of DriveClubs in New York City. “That’s because you have more muscles working hard, so it takes more energy for them to recover. This is when EPOC is prolonged.” Contrary to popular belief, a strength workout can actually challenge the cardiovascular system, too. “Your heart rate will definitely go up when you strength train, spiking right after you finish a set, before it starts to drop as you recover,” explains Tamir. “It won’t go up as much as doing HIIT or cardio though.”

Before deciding to quickly hit the weight rack for 20 minutes, you need to consider how many times a week you’re able to work out. “If you are doing a true strength workout you will probably only have time to focus on one body part to get enough volume to be effective in 20 minutes, since rest periods can range from 1–5 minutes,” explains Tamir. “That means you’d need to be able to get in 20-minute workouts 5–6 times a week, so you can split all body parts, which is ideal for strength or hypertrophy training.” Twenty minutes is going to be a limited amount of time to create continual strength benefits but will have benefits nonetheless.

With most things in life, the answer isn’t as simple as strength or cardio for the most beneficial 20-minute workout. If you’re limited on time and want to get the most bang for your buck, your best bet is to choose a full-body, interval workout that involves big compound movements, like squats, presses and pulls, explains Saladino. “This type of workout will give you the most benefit when it comes to both aerobic and anaerobic,” he says. “These movements will elevate your heart rate and create tension in the muscles, which is important if you want to build muscle tone and create a physique.”

The best way to structure the workout? “Start with some explosive speed and power to get the body moving fast and athletically, and then move into high-intensity interval training (HIIT) or a hypertrophy circuit,” suggests Saladino. “And try juggling the intensity levels each day.”