ASK NICOLE: How Long Should a Workout Be?

ASK NICOLE: How Long Should a Workout Be? April 9, 2019Leave a comment


Most training programmes tell you to exercise for about 20 minutes during each cardio workout. Is there a reason for this? I like to stretch my workouts out to 45 minutes, but I recently heard an exercise myth that after 20 minutes your body stops burning calories, which I strongly doubt.

My other question is; is weight training still effective if you target three muscle groups in one day or is it better to do each one separately? The reason I ask is that I don’t always make it to the gym and then I combine all the muscle groups I missed on a Saturday.



Hi Noelene,

When most people think of cardio they think of long, boring jogs or endless hours on the treadmill or bicycle. In my opinion, one of the best methods of cardio, which takes much less time and is far superior when trying to burn fat and increase fitness, is high-intensity interval training (HIIT). I always say quality is important, not quantity!

You also need to consider your goals. If you are an endurance athlete then you will need to exercise for long durations, but if your aim is weight loss or increased fitness then I would suggest shorter duration HIIT.

HIIT involves alternating between very intense bursts of exercise and low-intensity exercise (i.e. sprinting for 30 seconds, then walking for 60 seconds). Exercise physiologists previously thought that “steady state” cardio was superior for fat loss because more fat is readily available for use by the body as fuel at lower exercise intensities. However, we now know that at higher intensities you are burning far more energy – a great deal of which comes from fat. There is also something called an ‘after burn effect’, which means you can burn calories for up to 24 hours after a HIIT session, whereas a steady jog has almost no ‘after burn effect’.

If you are a beginner I would recommend only trying HIIT if you can do a session of cardio for 20-30 minutes at about 70-85% of your max heart rate. It is also advisable to have a health assessment before you start. Your current fitness level is one of the primary factors used to determine your workout frequency and intensity. Beginners will typically need more recovery time between workouts than more advanced trainees or well-conditioned athletes.

Some people also try to combine cardio and weight training in the same workout. I wouldn’t suggest this as you spend a longer amount of time in the gym per session. This can increase the risk of injury due to fatigue. It is also likely that you’ll be too tired to workout at the correct intensity during either your subsequent weights or cardio session.

I suggest splitting your cardio and weight training and perform them on different days (unless you’re well conditioned and can handle it). With this split approach, you’ll find that your intensity, performance and, eventually, your progress will be enhanced.

The key to resistance training is to give the targeted muscles 48 hours of recovery time before working them again. As such, performing cardio on the days between your weight sessions shouldn’t hamper your recovery. In fact, some people find that it reduces delayed onset muscle soreness and stiffness. The amount of time that you can dedicate to training each week is what will ultimately decide how often you can train.

If you only have an hour a day to train there are a couple of different approaches you could take. You need to see which fits best with your lifestyle and, most importantly, takes your ultimate goal into consideration. If adding muscle is your primary goal your focus should be weight training. If cardiovascular fitness is more important then your focus should be cardio.

One option is to design three, one-hour workouts that focus on high intensity resistance training performed on Monday, Wednesday and Friday, along with two 30 minute sessions of HIIT cardio on Tuesday and Thursday.

The best approach to determining the right training frequency is to ease into your workout schedule slowly and take note of the changes you experience. Record your progress in a book, making notes on how you feel. This will help you determine the right workout frequency.

I also try to limit my workouts to 40-60 minutes. Though some people tend to think that more time in the gym means you get more out, the truth is that after 30-40 minutes the benefit isn’t always as great as you have to lower the intensity of your workouts.

To answer your second question, instead of isolating your muscles why don’t you try to maximise your time in the gym by doing compound exercises that work multiple muscle groups. With just a few exercises you could get a full-body workout. Another benefit is that your muscles are working together as they do in the real world, delivering functional strength.

You can also maximise your workout by performing exercises while standing on one leg or on a Swiss ball. These types of exercises require greater balance while lifting, which activates your core muscles. This improves your overall body strength and allows you to lift more over time. It also enhances your mind-body connection.

And don’t stick to the same workout routine for too long, as your body will adjust to the stress and will stop adapting. For strength training, change your routine every few weeks and cross train for cardio rather than just running every time.

If you take all of these tips into consideration you could get by with four days of exercise a week if you focus on your intensity, form and technique.

Hope that helps!

Good luck!

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