The Least Amount of Exercise You Should Do (Lifting, Walking, HIIT, & Zone 2)

Movement

What It Is

The Minimum Effective Dose (MED) is the least amount of effort needed to achieve meaningful fitness results. It’s a no-frills, efficient approach for busy individuals or anyone looking to stay consistent without overdoing it.

Think of it as the "get-in-and-get-out" strategy for fitness. Whether you’re a busy parent or entrepreneur, someone who wants to ensure they are well rounded, or just someone who hates exercise, this is for you. By focusing on the MED, you hit the sweet spot of effort and benefit—enough to keep you healthy and balanced without the overwhelm of endless workouts.

What the Science Says

• Lifting: Prevents osteoporosis, sarcopenia, and low back pain. It improves insulin resistance, glucose metabolism, blood pressure, GI function, and body fat. And downstream from these factors lie metabolic diseases such as hypertension and heart disease. Plus, lifting decreases the risk of cancer and diabetes (in just 30 min a week).

• Zone 2: Improved mitochondrial efficiency, enhanced endurance, better fat metabolism, and a reduced risk of injury. It also supports recovery, boosts mental health, and lowers the risk of chronic diseases, making it a cornerstone of fitness for elite athletes and everyday individuals alike.

• HIIT (High-Intensity Interval Training): Triggers significant cardiovascular adaptations, including improvements in maximal oxygen uptake (VO2 max). It also improves glycemic control, improves fat oxidation, and stimulates the release of growth hormone.

• Walking: Walking volume and walking pace were strong independent predictors of the overall risk of all-cause mortality, however, pace (48%) was a stronger predictor than the number of steps a day (26%). A 2020 cohort study backed this up and found that walking more is correlated with "greater sleep efficiency, lower frequency of awakening after sleep onset, and shorter WASO [awake after sleep onset] and naptime." Plus, walking fewer than 2,700 steps per day is linked to a 200% higher risk of death—far exceeding the 70-80% risk increase from smoking or the 4% from obesity.

How to Do It

Walking

• The MED: For walking, 8,000 steps per day is the minimum effective dose if you’re under the age of 60. If you’re over the age of 60 then the minimum effective dose is 6,000 steps per day,

• How To Do It: One foot in front of the other. I’m only half kidding as the average American gets less than 4,000 steps per day. Spread your steps throughout the day. Research has shown that even if you get adequate exercise one day but fail to move enough throughout the rest of the day then you’re not as healthy. Also, walk faster. Walking at a pace that is at least moderate in intensity, or 100 steps/minute, is correlated to greater health benefits.

Lifting

• The MED: The Minimum Effective Dose of lifting is 40 minutes a week spread out over 2-3 sessions.

• How To Do It: This does not mean doing 3 sets of 10 reps of bicep curls with your 5-pound dumbbells. These reps must be compound movements (bilateral, multi-joint movements like rows and squats) with heavy weights.

H.I.I.T.

• The MED: Given that HIIT is so versatile, the minimum effective dose can be applied in a few different ways as long as you hit the core concepts of HIIT:

  1. Do 8x20 seconds of high intensity with 10 seconds of rest twice a week (Tabata)

  2. Do 5x4 minutes of high-intensity work with 4 minutes of rest between sets every other week

  3. Do 30x4 seconds of high intensity with 15-30 seconds of rest between sets 3 times a week

• How To Do It: There are many different ways to get an effective HIIT workout if these three components are checked off:

  1. Intensity: Performing exercises at a high-intensity level, pushing your limits during the work intervals. This intensity should be challenging and elevate your heart rate significantly.

  2. Duration: HIIT workouts are typically shorter in duration compared to traditional steady-state cardio exercises. The total duration of a HIIT session can range from as little as 4 minutes to around 30 minutes, depending on fitness level and workout design.

  3. Interval Ratios: HIIT workouts are structured using specific work-to-rest ratios with an emphasis on true rest when you’re not pushing it. Common ratios include 1:1 (equal work and rest intervals), 2:1 (twice as long rest intervals as work intervals), or even higher ratios.

Zone 2 Training

• The MED: The minimum effective dose of Zone 2 training is 3 hours a week, ideally performed at 45-60 minutes at a time.

• How To Do It: Choose any endurance-based activity where you can maintain a generally consistent heart rate. This could be running, rucking, rowing, cycling, or ellipticalling. The talk test, the MAF method, determining 60-75% of your max heart rate, and measuring your lactate are all methods to know if you’re in Zone 2 (see here for details).

To find out more about the minimum effectiveness of exercise, including specific exercises and equipment, see here.

Live well,

Brian

References

1. Momma, H., Kawakami, R., Honda, T., & Sawada, S. S. (2022). Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: A systematic review and meta-analysis of cohort studies. British Journal of Sports Medicine. https://doi.org/10.1136/bjsports-2021-105061

2. O’Connor, P. J., Herring, M. P., & Caravalho, A. (2010). Mental health benefits of strength training in adults. American Journal of Lifestyle Medicine, 4(5), 377–396. https://doi.org/10.1177/1559827610368771

3. Buchheit M, Laursen PB. High-intensity interval training, solutions to the programming puzzle. Part II: anaerobic energy, neuromuscular load and practical applications. Sports Med. 2013 Oct;43(10):927-54. doi: 10.1007/s40279-013-0066-5. PMID: 23832851.

4. Atakan MM, Li Y, Koşar ŞN, Turnagöl HH, Yan X. Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective. Int J Environ Res Public Health. 2021 Jul 5;18(13):7201. doi: 10.3390/ijerph18137201. PMID: 34281138; PMCID: PMC8294064.

5. Kessler HS, Sisson SB, Short KR. The potential for high-intensity interval training to reduce cardiometabolic disease risk. Sports Med. 2012 Jun 1;42(6):489-509. doi: 10.2165/11630910-000000000-00000. PMID: 22587821.

6. Jayedi, A., Gohari, A., Shab-Bidar, S., Ebrahimof, S., & Salari-Moghaddam, A. (2021). Daily step count and all-cause mortality: A dose-response meta-analysis of prospective cohort studies. Sports Medicine, 51(12), 2237–2250.

7. Kimura N, Aso Y, Yabuuchi K, Matsubara E. Association between objectively measured walking steps and sleep in community-dwelling older adults: A prospective cohort study. PLoS One. 2020 Dec 14;15(12):e0243910. doi: 10.1371/journal.pone.0243910. PMID: 33315927; PMCID: PMC7735606.

8. Hamer M, Chida Y. Walking and primary prevention: a meta-analysis of prospective cohort studies. Br J Sports Med. 2008 Apr;42(4):238-43. doi: 10.1136/bjsm.2007.039974. Epub 2007 Nov 29. PMID: 18048441.