PhysEd: Do We Have to Cool Down After Exercise?

Cooling Down After Exercise

Story at-a-glance -

  • Cooling down after exercise has long been promoted as a necessary step to help prevent muscle soreness and improve recovery, but new research suggests it does little to reduce muscle pain or improve recovery
  • A proper cool down does help lower your raised heart rate down to resting heart rate safely, and may also help you to simply unwind after an intense workout, easing the transition back to your normal level of activity
  • With no negative effects reported, and some potential benefit, even if it is merely psychological, if you enjoy cooling down you should continue, but if not, don’t worry about skipping it

By Dr. Mercola

If you’re like most people, the time you spend exercising is a valuable commodity that you’ve carefully planned and fit into your day. And when your workout is over, you may simply grab a quick shower or pull on a sweatshirt, skipping the post-exercise cool down because you’re eager to get on with your day.

Cooling down after exercise has long been touted as a necessary step to help prevent muscle soreness and improve recovery, but is it really?

The Case for Skipping Your Post-Exercise Cool Down

In 2007, one of the first studies on cooling down was published.1 The finding? Cooling down for 10 minutes after a workout had no impact on delayed-onset muscle soreness. Even though more than half a decade has passed, these results have yet to translate into practice, as most people are still under the impression that a cool down is beneficial.

Yet, newer research also suggests that the choice to cool down is simply one of personal preference – not one that will drastically impact your recovery. For instance:

  • Cooling down after performing strenuous forward lunges had no impact on muscle pain the next day among active adults; those who cooled down had the same amount of pain as those who did not2
  • Cooling down after soccer practice had no impact on performance, flexibility or muscle soreness the next day among professional soccer players3, 4

While it appears unlikely that cooling down has any real benefit in your post-workout recovery, muscle pain or next-day performance, it may help prevent the buildup of blood in your veins, which can lead to dizziness or fainting.5

The cool down also brings fresh blood into areas to help with lactic acid removal, while bringing your heart rate down to resting pulse quicker. A proper cool down also helps lower a raised heart rate down to resting heart rate safely.

Further, it may also help you to simply unwind after an intense workout, easing the transition back to your normal level of activity.

Personally I only cool down for three minutes after doing a high-intensity workout. If you are pushing your body to extremes it makes loads of sense to do a cool down, especially if you are close to or exceeding your maximum calculated heart rate (220 minus your age).

Static Stretching Before Exercise: Another Myth Busted

As with cool downs, stretching before exercise is another fitness dogma many of us wouldn’t dare neglect. After all, we’ve been told for decades that stretching is key for warming up your muscles and helping to prevent injuries.

However, pre-exercise static stretching generally hurts rather than helps your athletic and muscle performance, particularly when the stretch is held for 60 seconds or more.6 Static stretching is when you hold your muscle in a fixed position for a prolonged period, such as bending over to touch your toes.

This technique has been regarded as the gold standard for decades, but now research shows that it actually decreases the blood flow within your tissue creating localized ischemia (a restriction in blood supply) and lactic acid buildup. This can potentially cause irritation or injury of local muscular, tendinous, lymphatic, and neural tissues.

The evidence is so clear that the American College of Sports Medicine now advises against this form of stretching prior to your workouts. Unlike the cool down, however, which you can generally safely skip, all forms of stretching should not be avoided prior to exercise, only static stretching.

Dynamic stretching, on the other hand, has been shown to positively influence power, speed, agility, endurance, flexibility, and strength performance when used as a warm-up.7 And unlike cool-downs, warm-ups are very important and have been shown to help reduce and prevent muscle soreness.8

My favorite type of dynamic stretching is active isolated stretches developed by Aaron Mattes. With Active Isolated Stretching or AIS, you hold each stretch for only two seconds, which works with your body's natural physiological makeup to improve circulation and increase the elasticity of muscle joints.

This technique also allows your body to help repair itself and prepare for daily activity. If you’re an avid exerciser, this news to overhaul your pre-workout stretches and your post-workout cool-down may come as a surprise, but these tips can help you to make the most of your workouts.

More Tips for Optimizing Your Workouts: The Benefits of Short and Intense Activity

If you’re excited at the prospect of cutting down your workout time by skipping your cool-down, you’ll be even more enthused to learn about high-intensity interval training (HIIT). Remember, if you do this type of exercise I do believe a three-minute cool down is important.

Researchers have repeatedly confirmed the superior health benefits of HIIT compared to traditional and typically performed aerobic workouts. For example, high-intensity interval-type training gives a natural boost to human growth hormone (HGH) production—which is essential for optimal health, strength and vigor—and has been shown to significantly improve insulin sensitivity, boost fat loss, and increase muscle growth. Anaerobic HIIT can be performed on a recumbent bike or an elliptical machine, or sprinting outdoors (with proper guidelines to avoid injury). You can even perform high-intensity strength training.

While there are a large number of variations, the HIIT routine I recommend involves going all out for 30 seconds and then resting for 90 seconds between sprints, as demonstrated in the video above The total workout is typically 8 repetitions. In all, you’ll be done in about 20 minutes, and you only need to perform HIIT two or three times a week.

Contrary to popular belief, extended extreme cardio actually sets in motion inflammatory mechanisms that damage your heart. So while your heart is indeed designed to work very hard, and will be strengthened from doing so, it’s only designed to do so intermittently, and for short periods—not for an hour or more at a time. This is the natural body mechanics you tap into when you perform HIIT.

How to Round Out Your Exercise Program

In addition to doing high-intensity interval exercises a couple of times a week, it’s wise to alternate a wide variety of exercises in order to truly optimize your health. As a general rule, as soon as an exercise becomes easy to complete, you need to increase the intensity and/or try another exercise to keep challenging your body. I recommend incorporating the following types of exercise into your program on days when you’re not doing HIIT:

  • Strength Training: If you want, you can increase the intensity by slowing it down. You need enough repetitions to exhaust your muscles. The weight should be heavy enough that this can be done in fewer than 12 repetitions, yet light enough to do a minimum of four repetitions. It is also important NOT to exercise the same muscle groups every day. They need at least two days of rest to recover, repair and rebuild.
  • For more information about using super slow weight training as a form of high-intensity interval exercise, please see my interview with Dr. Doug McGuff.

  • Core Exercises: Your body has 29 core muscles located mostly in your back, abdomen and pelvis. This group of muscles provides the foundation for movement throughout your entire body, and strengthening them can help protect and support your back, make your spine and body less prone to injury and help you gain greater balance and stability.
  • Exercise programs like Pilates, yoga, and Foundation Training are great for strengthening your core muscles, as are specific exercises you can learn from a personal trainer.

  • Stretching: As mentioned, my favorite type of stretching is Active Isolated Stretching (AIS) developed by Aaron Mattes. This technique allows your body to repair itself and prepare for daily activity. You can also use devices like the Power Plate to help you stretch.