Should You Prioritize High or Moderate-Intensity Exercise?
There are benefits to each
If you aren’t panting or dripping sweat, was the workout even worth completing?
I know many people who would argue it’s not, falling in line with the “no pain no gain” mindset. This is a potentially dangerous mindset, particularly in a rehabilitation setting. When I’m working with patients or conditioned clients, I am always hyper-aware of the individuals training history and how they are likely to respond to a bout of exercise.
Let’s assume you are programming appropriately and your recovery strategies (sleep and diet) are on point. Do you need to push yourself to exhaustion every session?
Give your body a break
A recent study by Lee and colleagues aimed to bridge this gap by examining the association between exercise intensity and mortality rates. Lee and team utilized data from the Nurses’ Health Study and Health Professionals Follow-up Study, tracking over 116,000 participants for several years. They analyzed the effects of both moderate-intensity (less than 6 METs) and vigorous-intensity (6 METs or more) exercise on mortality rates.
METs are measurements of oxygen consumed during physical activity. Instead of attempting to calculate your exact amount, you can use charts to get rough estimates. This site has some good examples. Brisk walking or weight training with low rest breaks would be moderate intensity (4–5 METs) while circuit training and running would be vigorous intensity (8–11 METs).
It should be noted that vigorous intensity has a much wider variety of activities and intensity levels than moderate intensity. The difference between walking at a very brisk pace (4.5 mph) and sprinting up a hill is substantially greater than golf and household chores. Regardless, its a useful comparison.
The study highlighted the significant benefits of vigorous-intensity exercise in reducing mortality, particularly at 75–144 minutes per week. Meeting the threshold reduced for all-cause mortality by 19%, cardiovascular disease (CVD) mortality by 31%, and non-CVD mortality by 15%.
Moderate-intensity exercise showcased continuous benefits at higher volumes than vigorous intensity. Engaging in 150–299 minutes per week of moderate-intensity exercise improved longevity, leading to 19% to 25% lower risk of all-cause, CVD, and non-CVD mortality.
Both exercise intensities did eventually plateau around 2 to 4 times above the recommended minimum of long-term leisure-time physical activity. Vigorous intensity exercise for 150–299 minutes per week lowered mortality by 2–4% while moderate intensity exercise for 300–599 minutes per week lowered mortality by 3–13%. No clear benefits were shown beyond those durations.
That doesn’t mean there aren’t any more advantages. It’s important to always know what outcomes a research study is assessing. More volume is likely to lead to greater improvements in strength, power, muscle mass, and VO2 max (depending on the type of exercise). Those are more narrow benefits than mortality, which is affected by many other factors.
It’s essential to understand that neither moderate-intensity exercise is superior nor is higher volumes of vigorous exercise unnecessary. Vigorous intensity exercise does not require the same volume as the higher intensity yields more rapid improvements. However, the higher intensity requires more recovery time and it can be more unpleasant. Personally, I prefer short bouts of high intensity to long bouts of moderate intensity.
Apart from mortality rates, the study explored exercise’s impact on specific cardiovascular diseases. Vigorous-intensity exercise demonstrated a more substantial reduction in the risk of coronary heart disease and stroke compared to moderate-intensity exercise.
Remember, these are mean results. All the data is averaged together and assesses trends. The overlapping confidence intervals show some individuals may experience the opposite results. Use mean data as a starting point and then personalize your exercise programming.
Practical Recommendations
So, what are the takeaways from the study? How can you apply this information to your life? Here are my interpretations, filtered through professional experiences.
- Optimize Limited Time: If time is limited, prioritize vigorous-intensity exercise. This can be high-intensity interval training or rest-reducing resistance training strategies, such as rest-pause, supersets, or drop sets.
- Moderation with Available Time: If time is not an issue and you can exercise 5+ hours per week, you can mix moderate and vigorous intensity exercise. They both provide benefits and should both be used. Too much vigorous-intensity exercise may increase injury risk and lead to overtraining. Too little vigorous-intensity exercise will limit strength and VO2 max improvements.
- Embrace Exercise: Regardless of intensity, more exercise generally translates to better health. Integrating physical activity into daily routines, enjoying various activities, and finding what fits are key aspects of a healthier lifestyle.
Unless you are a competitive athlete, you don’t need to worry about fine-tuning your exercise to a high degree. You can make it easy by choosing exercises that fall into one category, such as brisk walking (moderate) and sprinting (vigorous).
If you like HIIT or CrossFit.com for easy exercise selection, be aware of your intensity. Those workouts are typically vigorous. Perform those 3–4 times a week and then mix in long walks or easy bike rides.
As a baseline, aim to meet the physical activity guidelines. Achieve at least 75 minutes of vigorous or 150 minutes of moderate aerobic activity a week plus at least two sessions of resistance training.
Find what works best for you.
Interested in learning more about fitness and rehabilitation? Check out the Clinical Gap Podcast.