Tag Archives: excercise

Paleolithic aging Exercise for brain, biceps, and longevity


The ideal diet remains controversial in health circles, but the benefits of exercise are almost universally acknowledged. And while many associate exercise with weight loss or toning up, evidence is quietly accumulating that our brains and immune systems need it as much as our glutes, abs, and pectorals.

 November 2019 study published in the Journal of the American Geriatric Societylooking at the longterm effects of diet and exercise on neurodegeneration showed how even modest exercise can help stave off dementia. It is just one of many examples that remind us how important exercise and movement are to overall brain health[1]

The study measured exercise- and diet-driven improvements in neurocognition (including executive functions, memory, language and fluency, and clinical dementia rating) over six months and in a one-year followup. The results have strong implications for older, sedentary adults. Progress recorded after six months was still clearly measurable at the one-year mark, even if exercise was abandoned.

The study also included a “heart healthy” dietary intervention called DASH (Dietary Approaches to Stop Hypertension)similar to the Mediterranean diet. This aspect of the study targeted cardiovascular disease (CVD) factors present in each participant.

Would an ancestral diet have shown competitive results? A September 2019 study published in CUREUSwhich looked at a carbohydrate-restricted diet and exercise on cognitive function also showed success (including improvement of the critical executive functions) using a low-carb Paleolithic Diet and exercise. [2]

Both studies conclude that the protective and cognition-enhancing effects of diet and exercise, taken together, exceed the benefit of either by itself.


The importance of “executive function 

The importance of executive function to overall cognition is critical. Adele Diamondprofessor of neuroscience at the University of British Columbia described them in her review article from the Annual Review of Psychology: “[EFs] make possible mentally playing with ideas; taking the time to think before acting; meeting novel, unanticipated challenges; resisting temptations; and staying focused.” EFs allow for many higherlevel functions such as inhibition, working memory, and cognitive flexibility. Without them, mental decline is inevitable. [3]

She also states that lack of exercise, among other factors (including stress and lack of sleep), compromise EFs. [3]

EFs appear to underlie most of what we might consider “personality,” and keep us from defaulting to “autopilot” when selecting actions. EFs help us behave in context, allow us to combat bad habits or adopt good ones (like Paleo Diet), and make difficult but worthwhile choices. Sadly, EFs are often early casualties when Alzheimer’s or other dementias set in. [4]


Different methodologies, similar results 

Both of the 2019 studies exploring diet, exercise, and cognitive function demonstrated EF improvement through exercise and diet, even though the demographics and methodologies varied.

The 160 participants in the study exploring the DASH diet were middle-aged, sedentary, had at least one CVD risk factor, and all displayed “cognitive impairment with no dementia” or CIND. CIND is not a dementia diagnosis but is considered dementia-predictive. The exercise groups performed 35 minutes of low impact aerobic exercise (walking or biking) three times per week for six months.

The Paleolithic Diet study measured a smaller group (12 individuals ages 20-40 with metabolic syndrome) over a shorter period, with more intensive exercise. Each participant engaged in high intensity interval training (HIIT) on three days per week for four weeks, including 6 x 60second cycling intervals at 90 percent of maximum heart rate.

Both studies measured diet-only versus diet-and-exercise groups and showed the highest rate of cognitive improvement with the diet-and-exercise interventionThe DASH study, with its one-year follow-up, also showed that the improvements, while possibly attenuated if exercise stopped, were still measurable compared to the non-exercise baseline.

The improvement in executive function across a wide spectrum of age groups in both studies clearly shows the importance of regular exercise to build, improve, and preserve mental acuity—at any age.


Exercise and other diseases 

Regular exercise has been repeatedly shown to improve many other serious health conditions. Let’s take a closer look.


A 2019 Mayo Clinic article entitled Your secret weapon during cancer treatment? Exercise!, [5outlined how exercise offers a range of benefits, from improving well-being during treatment to decreasing tumor size. In 2018, The Clinical Oncology Society of Australia formally adopted treatment guidelines to include exercise as integral to cancer treatment [6] based in part on an extensive review exploring the efficacy of exercise on cancer treatment. [7]


Exercise improves insulin sensitivity and combats common Type II diabetes co-morbidity factors (obesity, high blood pressure). [89] A position statement of the American Diabetes Association on exercise states: “The adoption and maintenance of physical activity are critical foci for blood glucose management and overall health in individuals with diabetes or prediabetes.” [10] The position statement cites 185 different studies and papers supporting these exercise recommendations.


The first sentence in a NIH/U.S. National Library of Medicine post in “Medline Plus” on heart disease reads: “Getting regular exercise when you have heart disease is important. Physical activity can strengthen your heart muscle and help you manage blood pressure and cholesterol levels.” [11] The preventive benefits of exercise for heart disease are widely acknowledged. Sadly, one recent study in Frontiers in Cardiovascular Medicine (September 2018) concluded that while exercise shows “unequivocal benefits” and “mortality risk reduction,” the vast majority of Americans simply don’t do it enough. [12]


Moderate exercise is widely acknowledged to boost the immune system and mitigate immunosenescence—the dysregulation of immune processes due to aging. [13] There is some debate about whether extended, intense exercise, elite endurance competitions and training, or active duty military deployments temporarily depress the immune system. A 2020 study published in the Exercise Immunology Review makes a strong case against this theory, noting that much of the evidence is epidemiological and that more randomized trials are needed. [14] Luckily, most moderate exercisers or sedentary older adults won’t reach this “elite” level of intensity 

A quick Google search will yield similar information for almost any health condition—especially chronic diseases such as obesity, metabolic syndrome, multiple sclerosis, arthritis, or hypertension.


Exercise guidelines 

Many studies recommend working up to baseline goals of either 150 minutes per week of moderate activity or 75 minutes per week at “vigorous” levels as suggested by the Mayo Clinic. [5] Resistance training should be incorporated, ideally, at least twice a week.

Older adults should prioritize building, or at least maintaining, muscle mass through resistance or weight training to combat the silent enemy sarcopenia. This condition, the gradual loss of muscle as we age, predisposes us to disability, fall-related injuries, reduction in stature, and is linked to many chronic diseases—resulting in shorter lifespan. [15]

New exercise programs should be adopted gradually. Over four years, for example, the author (currently 62 and employed fulltimewent from two, 30-minute weightlifting sessions plus two to three days of walking 30 minutes each week, to four, 60-minute weight sessions (each followed by 30 minutes walking) plus two additional days of walking 60-90 minutes per week. Once or twice a month he and his wife take an extended hike of two hours or more.

The time investment per day can be challenging but should pay off in greatly reduced morbidity at advanced age. “Retirees” with more leisure hours available have a priceless opportunity to combat disease and extend the productive, assistance-free phase of their lives with moderate, consistent exercise.

Sedentary individuals, especially those with health issues, should always consult their physician before beginning an exercise program—but it’s never too late to start.




  1. Blumenthal, James A., et al. “Longer Term Effects of Diet and Exercise on Neurocognition: 1-Year Follow-up of the ENLIGHTEN Trial.” Journal of the American Geriatrics Society, vol. 68, no. 3, 2020, pp. 559–68. Wiley Online Library, doi:10.1111/jgs.16252. 
  2. Gyorkos, Amy, et al. “Carbohydrate-Restricted Diet and Exercise Increase Brain-Derived Neurotrophic Factor and Cognitive Function: A Randomized Crossover Trial.” Cureus, vol. 11, no. 9. PubMed Central, doi:10.7759/cureus.5604. Accessed 8 Apr. 2020.
  3. Diamond, Adele. “Executive Functions.” Annual Review of Psychology, vol. 64, 2013, pp. 135–68. PubMed Central, doi:10.1146/annurev-psych-113011-143750.
  4. Newport, Mary T. Alzheimer’s Disease: What If There Was a Cure?: The Story of Ketones. Second edition, Basic Health Publications, Inc, 2013.
  5. “Your Secret Weapon during Cancer Treatment? Exercise!” Mayo Clinic, https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/secret-weapon-during-cancer-treatment-exercise/art-20457584. Accessed 8 Apr. 2020.
  6. MPH, Monique Tello, MD. “Exercise as Part of Cancer Treatment.” Harvard Health Blog, 13 June 2018, https://www.health.harvard.edu/blog/exercise-as-part-of-cancer-treatment-2018061314035.
  7. Heywood, Reginald, et al. “Efficacy of Exercise Interventions in Patients With Advanced Cancer: A Systematic Review.” Archives of Physical Medicine and Rehabilitation, vol. 99, no. 12, 2018, pp. 2595–620. PubMeddoi:10.1016/j.apmr.2018.04.008.
  8. “Type 2 Diabetes and Exercise.” EndocrineWeb, https://www.endocrineweb.com/conditions/type-2-diabetes/type-2-diabetes-exercise. Accessed 8 Apr. 2020.
  9. Whiteside, David. Active into Your 90’s: Exercise and Paleo —. 22 Jan. 2018, https://www.paleo55plus.com/post/active-into-your-90-s-exercise-and-paleo.
  10. Colberg, Sheri R., et al. “Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association.” Diabetes Care, vol. 39, no. 11, Nov. 2016, pp. 2065–79. care.diabetesjournals.org, doi:10.2337/dc16-1728.
  11. Being Active When You Have Heart Disease: MedlinePlus Medical Encyclopedia. https://medlineplus.gov/ency/patientinstructions/000094.htm. Accessed 8 Apr. 2020.
  12. Nystoriak, Matthew A., and Aruni Bhatnagar. “Cardiovascular Effects and Benefits of Exercise.” Frontiers in Cardiovascular Medicine, vol. 5, Sept. 2018. PubMed Central, doi:10.3389/fcvm.2018.00135.
  13. Nieman, David C., and Laurel M. Wentz. “The Compelling Link between Physical Activity and the Body’s Defense System.” Journal of Sport and Health Science, vol. 8, no. 3, May 2019, pp. 201–17. ScienceDirectdoi:10.1016/j.jshs.2018.09.009.
  14. Simpson, Richard J., et al. “Can Exercise Affect Immune Function to Increase Susceptibility to Infection?” Exercise Immunology Review, vol. 26, 2020, pp. 8–22.
  15. Volpi, Elena, et al. “Muscle Tissue Changes with Aging.” Current Opinion in Clinical Nutrition and Metabolic Care, vol. 7, no. 4, July 2004, pp. 405–10.

Interval Training: Stop with the Tabatas and Do Some Gibalas! | The Paleo Diet

Sprinting would obviously have been a necessary requirement for Paleolithic hunter-gatherers, both for the procurement of food and to avoid becoming food! Those who want to argue against that statement with the “persistence hunting” position, I will address that in a future post. Regardless, let’s fast forward to modern day and address a topic pertinent to my initial statement. To say that “Tabatas” have become an extremely popular interval training protocol in the fitness industry would be an understatement. When I wrote a position paper1 back in 2008 on the benefits of sprint interval training, the research conducted by Izumi Tabata et al. was obviously referenced as it added to the body of evidence that supports the benefits of high-intensity intermittent (interval) training (HIIT). However, the interpretation of this protocol in the fitness industry has often been misunderstood, and even when done correctly, I would argue that, for most individuals, it is not the most effective approach to interval training. After all, the protocol tested was simply one that was first introduced by a head coach of the Japanese National Speed Skating Team, Kouichi Irisawa; a protocol one would assume worked well for certain athletes based upon the duration of their events. Further, most good coaches use training methods that are often experimentations that change with time, as more successful protocols take shape. Along these same lines, I believe most people could improve their investment of time by not using the Tabata protocol for their interval training; but rather, use a different approach.

For the uninformed, in 1996, Tabata et al. published the findings of a study comparing moderate-intensity endurance training (MIET – 70% VO2 max for 60 minutes, 5 days per week) with HIIT (170% VO2 max for 20 seconds x 7-8 with 10 seconds recovery, 5 days per week) on a cycle ergometer.2 The study found that HIIT improved maximal oxygen uptake slightly more than MIET; but, also improved the anaerobic capacity by 28% while the MIET had no effect on the anaerobic capacity. So, essentially, a “two for one” in terms of improving metabolic capacities for the HIIT protocol.

While the results of the study were important for the comparison of MIET to HIIT, other interval training protocols have demonstrated similar and; in some cases, even greater benefits with a decreased investment of time.3, 4, 5, 6 These latter studies support what I have witnessed clinically over nearly 20 years, which is, that intensity, not duration, is the key ingredient for beneficial physiological change. The intensity of the HIIT protocol examined in the Tabata study was 170% VO2 max, which, while correctly being labeled supramaximal (above 100% VO2 max) and certainly “high-intensity,” is nowhere near a maximal sprint effort given that humans are capable of intensities around 250%. The power output sustained for a maximal effort for the duration of the exercise time of the Tabata HIIT protocol (140 seconds to 160 seconds), is very different to the power output sustained for a maximal effort for an “all-out” sprint lasting, say, 30 seconds. If 170% VO2 max was all one had to escape a predator in primitive times (or today for that matter), it is pretty much a guarantee that you are going to be out of the gene pool in short order! 100% VO2 max represents the power output attained when one reaches maximal oxygen consumption during a graded exercise stress test. Any human starting out at that equivalent intensity would not find it anywhere near a maximal effort for a short “all-out” sprint.

When sprinting “all-out,” most individuals are going to start slowing down within seconds; but, could probably still hold a decent percentage of their maximum power output for anywhere between 20-60 seconds, depending on their level of conditioning, and, in particular, their ability to handle the lactic acid production associated with supramaximal exercise. Considering the short duration of supramaximal activity, it generates a relatively large volume of excess post-exercise oxygen consumption (EPOC), partly due to the lactic acid production. Research has shown a significantly larger EPOC is generated for a 45 second “all-out” sprint compared to a 30 second “all-out” sprint, and a significantly larger EPOC is generated for a 60 second “all-out” sprint compared to a 45 second “all-out” sprint.7 However, a 90-second “all-out” sprint did not generate a larger EPOC than a 60 second “all-out” sprint. The reason for this is that lactic acid production typically reaches its peak at around 60 seconds of supramaximal exercise, which, in turn, inhibits muscular contraction and thereby decreases the production of further large quantities of lactic acid.  Anyone can easily experience this for him or herself. There simply is not a human on the planet that can maintain close to maximal power output without a precipitous drop-off at around 60 seconds. If you find otherwise, immediately contact your country’s Olympic Committee as I can assure you that you will be in high demand! So, 60 seconds is essentially a maximal and optimal duration to engage in supramaximal activity. Perhaps selective pressure with respect to our ancestral survival played a part in this physiological reality.

Now, back to the Tabata protocol. There are two ways in which individuals in the fitness community are misinterpreting this methodology. First, and perhaps somewhat ridiculously, are those individuals and classes that label their work-outs as “Tabatas” because they simply exercise for 20 seconds (at relatively low intensities), rest for 10 seconds, and then repeat the same for seven to eight intervals, and then, in some cases, even repeat again for an hour long workout. Anyone engaging in this approach is as far away from supramaximal interval training as one can get. The second misinterpretation comes from those that are completing the seven to eight 20 second intervals as “all-out” efforts.  With this approach, based upon the previous discussion about 60 seconds being a maximal duration for “all-out” exercise, any intervals past the first three 20 second sprints are essentially a waste of time. The only way someone can complete seven to eight 20-second intervals with only a 10-second recovery is to back down from an “all-out” sprint, to an intensity similar to that tested in the Tabata study. Doing this certainly has its merits for athletic endeavors that last for 140 seconds to 160 seconds; however, for the average individual and most athletes, I would argue that the protocol researched by the group headed by Martin Gibala from the Department of Kinesiology at McMaster University in Hamilton, Ontario, Canada, is a much more effective approach to interval training.

This protocol, as first described by Burgomaster et al.,3 involves completing “all-out” 30-second sprints (also on a cycle ergometer) with a 4 minute recovery between exercise bouts. The number of sprints increased from 4 during the first two sessions, to 5 in the third and fourth sessions, and 6 in the last two sessions. The total time commitment was 17–26 minutes per session, involving only 2–3 minutes of sprint exercise. Exercise sessions were completed every two to three days such that 16 minutes of exercise was completed in a two-week time period.  The results of this protocol showed a doubling of the participants’ endurance capacity! So these benefits occurred over a two-week period using just 16 minutes of sprinting. Further studies using this same protocol have been shown to substantially improve insulin action in young sedentary subjects, a much-needed outcome in this world full of metabolic syndrome.4 This demonstrates that quality not quantity causes physiological change for the better and, in many cases, the Tabata protocol in the fitness industry has become a methodology that has moved away from quality toward quantity. Further research has now shown that intense bouts as short as 6-20 seconds can have a tremendous benefit on physiological health, emphasizing, again, that intensity, not duration, is the key element to beneficial change.5,6 I have also found clinically, that these very short bouts of intense activity are better adhered to while still providing tremendous improvements in health and performance.

Moreover, I found a common objection to this methodology is that unfit and elderly individuals should not engage in this type of supramaximal activity due to the inherent dangers of engaging in such intense activity. With extensive experience in this field, I have never had a situation where an unfit individual or an elderly individual has had a problem with engaging in this kind of supramaximal activity. In fact, I would argue that it is beneficial to engage in this type of exercise in a controlled environment; rather than leave it to the reality of life where external pressures may demand an effort above which one is physiologically not trained to handle.  Interestingly, an increased QT dispersion (QTd) – a marker of myocardial electrical instability that predicts ventricular arrhythmias and sudden cardiac death – has been shown to be decreased with short-term supramaximal exercise.8 This supports the notion that short-term supramaximal exercise is an appropriate approach for anyone to improving one’s physiological health.

In closing, unless you have an athletic event lasting between 140 seconds to 160 seconds, skip the Tabatas and engage in Gibalas or some other shorter interval training protocol that produces better results with a smaller investment of time.  And don’t overdo the quantity of “all-out” sprints – eight to twelve minutes per week is sufficient to reap the benefits without the risks associated with overtraining.

Dr. Mark J. Smith

Dr. Mark J. Smith | The Paleo DietDr. Mark J. Smith graduated from Loughborough University of Technology, England, with a Bachelor of Science in PE & Sports Science and then obtained his teaching certificate in PE & Mathematics. As a top-level rugby player, he then moved to the United States and played for the Boston Rugby Club while searching the American college system for an opportunity to commence his Master’s degree. That search led him to Colorado State University where Dr. Smith completed his Masters degree in Exercise and Sport Science, with a specialization in Exercise Physiology. He continued his studies in the Department of Physiology, where he obtained his Doctorate. His research focused on the prevention of atherosclerosis (the build up of plaque in arteries that leads to cardiovascular disease); in particular, using low-dose aspirin and antioxidant supplementation. Read more…


1. Smith MJ. Sprint Interval Training – “It’s a HIIT! A research paper discussing the superior health and performance benefits of high-intensity intermittent exercise over low-to moderate-intensity continuous exercise. 2008 //docsmith.org/SIT-HIITbyMJS-1411.pdf

2. Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Med Sci Sports Exerc. 1996 Oct; 28(10): 1327-30

3. Burgomaster KA, Hughes SC, Heigenhauser GJ, Bradwell SN and Gibala MJ. Six sessions of sprint interval training increases muscle oxidative potential and cycle endurance capacity in humans. Journal of Applied Physiology 2005 98:1985-1990

4. Babraj JA, Vollaard NB, Keast C, Guppy FM, Cottrell G, Timmons JA. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males. BMC Endocrine Disorders 2009 Jan 28; 9: 3.

5. Adamson S, Lorimer R, Cobley JN, Lloyd R, Babraj J. High Intensity Training Improves Health and Physical Function in Middle Aged Adults. Biology 2014 3: 333-344.

6. Metcalfe RS, Babraj JA, Fawkner SG, Vollaard NB. Towards the minimal amount of exercise for improving metabolic health: beneficial effects of reduced-exertion high-intensity interval training. Eur J Appl Physiol.2012 Jul; 112(7):2767-75.

7. Withers RT, Van der Ploeg G, Finn JP. Oxygen deficits incurred during 45, 60, 75 and 90‐s maximal cycling on an air‐braked ergometer. Eur. J. Appl. Physiol. 1993; 67(2): 185‐91.

8. Drigny J , Gremeaux V, Guiraud T, Gayda M, Juneau M, Nigam A. Long-term high-intensity interval training associated with lifestyle modifications improves QT dispersion parameters in metabolic syndrome patients. Ann Phys Rehabil Med. 2013 Jul; 56(5):356-70.

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