Key-points

This post aims to give evidence-based recommendations on physical exercise for EAs.

Why exercise?

Exercise can enhance productivity (and thus impact) of EAs in two ways:

• Acute enhancement of cognitive performance.
• Medium and long-term improvement of physical and mental health.

How to exercise?

• Moderate and/or vigorous intensity “cardio” exercise for at least 20 minutes per day on at least 3 days per week is recommended.
• Additionally, resistance exercise (~ 3 x 10 repetitions with high intensity) for each of the major muscle groups should be performed on 2-3 days per week (can be combined with cardio).
• Implementation example: Daily active commuting (fast walking or riding bicycle for a total of ~ 30 min per day) and a twice-per-week visit to the gym (resistance exercise with initial supervision by a fitness-professional).
  

Introduction

I am an exercise scientist. My research focuses on the systemic physiology in endurance athletes and I am the exercise physiologist of the Swiss Olympic team. In this role, I have gotten in touch with spectacularly many and wildly different answers to the question “what is the best training strategy for maximal performance benefit?” Even in the elite sports domain (or maybe especially in the elite sports domain) there is much quackery going on when it comes to prescribing exercise. It is, for example, far more common for athletes and coaches to simply copy the fancy-looking training regimen from successful athletes’ blogs than to look at the scientific evidence for these interventions. The actual evidence on training for high performance, regrettably, is much less fancy (and also much less specific) than the average blog post may suggest…

I think the same might apply for the facet of exercise that is interesting for EAs - namely exercise to enhance productivity and thus impact. Although there has been some discussion on exercise in the community (e.g. here), I think it is fair to say that sports and exercise are not the most thoroughly researched topics within EA.

Let me, therefore, lay out in this post what I think are uncontroversial and evidence-based pieces of advice about the effect of exercise on health and productivity. Or: Why and how should EAs exercise?

Why exercise?

The scientific evidence is indisputable: Engaging in regular physical exercise and reducing sedentary behavior is vital for the health of adults. The most important findings associated with exercise include:

• Decreased risk of coronary heart disease, stroke and type 2 diabetes
• Decreased risk of colon and breast cancer
• Prevention of and improvement in depressive disorders and anxiety
• Improvements in body composition and strength
• Enhancement in feeling of “energy” and quality of life as well as decreased fatigue.
• Enhancement of cognitive function as well as lower risk of cognitive decline and dementia

In fact, it is hard to think of a health-related variable that is not affected by physical exercise in a positive way. Exercise really is medicine…

I think this is also relevant to us EAs. More specifically, I see two ways in which exercise can help us enhance our productivity and thereby our impact:

• First, immediately after and also during light- to moderate-intensity exercise, cognitive performance is (slightly) enhanced. Consequently, one can expect better cognitive functioning not only after an exercise session or after an active break but also during light exercise as for example a stroll.
• Second, and more importantly, medium- and long-term mental and physical health very clearly benefit from physical exercise. This means, one can expect better long-term productivity and impact when exercising regularly because one will simply be healthier.

So the case seems clear: We need to exercise regularly. But how much is enough to get the health benefits? And how is exercise done right?

How to exercise?

Recommendations

The available evidence supports a dose–response relationship between physical activity and health variables, such that greater benefits are associated with higher volumes of exercise. Even if the exact shape of the dose–response curve is not clear, it is reasonable to say ‘‘some exercise is good; more is better.’’ However, as the dose-response curve most likely reaches a plateau or even reverses at some point, we want to know the exercise dose that is high enough to get most of the health benefits and low enough not to be risky or very inefficient.

So here they are, the recommendations on physical exercise for health:

Cardio exercise (i.e. cardiorespiratory or “aerobic” exercise):

Type

• Regular, purposeful (i.e. beyond activities of daily living) exercise that involves major muscle groups and is continuous and rhythmic in nature is recommended.
  This can involve running, cycling, swimming, rowing, ball sports (e.g. football or tennis), group fitness (e.g. step aerobics), etc. and should be chosen according to personal taste.

Intensity

• Moderate and/or vigorous intensity [1] is recommended.
• Lower intensities may be beneficial in deconditioned persons.
• High intensity exercise (interval or circuit training, e.g. like this) can yield larger physiological adaptations per training session. However, high intensity exercise is mentally more demanding and may compromise exercise adherence in the long-term.

Volume (= Time)

• 30 – 60 min per day of moderate exercise, or 20 – 60 min per day of vigorous exercise (or a combination of both) are recommended.
• Smaller volumes can also be beneficial, especially in previously sedentary persons.

Frequency

• ≥ 5 days per week of moderate exercise, or
• ≥ 3 days per week of vigorous exercise, or
• a combination of moderate and vigorous exercise on ≥ 3–5 days per week

Pattern

• Exercise may be performed in one (continuous) session per day or in multiple sessions of ≥ 10 min to accumulate the desired duration and volume of exercise per day.
• Exercise bouts of < 10 min may yield favorable adaptations in very deconditioned individuals.

Progression

• A gradual increase (i.e. over weeks to months) of exercise dose by adjusting exercise duration, frequency, and/or intensity is reasonable until the desired exercise goal is attained.
• This approach may enhance adherence and reduce risks of musculoskeletal injury and adverse coronary heart disease events.

Resistance exercise:

Type

• Resistance exercises involving each major muscle group (i.e. chest, shoulders, back, hips/glutes, legs, trunk and arms) are recommended.
• A variety of exercise equipment and/or body weight can be used to perform these exercises. For example: Fixed resistance machines, free weights or resistance (rubber) bands.

Intensity

• 60%–70% of the 1RM (i.e. “one repetition maximum” [2]) (moderate to hard) for novice to intermediate exercisers.
• ≥ 80% of the 1RM (hard to very hard) for experienced strength trainers.
• 40%–50% of the 1RM (very light to light) for older and sedentary persons.

Volume (= Repetitions / Sets)

• 8–12 repetitions are recommended to improve strength and power.
• 10–15 repetitions are effective in improving strength in persons starting exercise.
• Two to four sets (i.e. cycles of repetitions) are recommended to improve strength and power.
• A single set of resistance exercise can be effective especially among older and novice exercisers.

Frequency

• Each major muscle group should be trained on 2–3 days per week.

Pattern

• Rest intervals of 2–3 min between each set of repetitions are effective.
• A rest of ≥ 48 h between sessions for any single muscle group is recommended.

Progression

• A gradual progression (i.e. over weeks to months) of greater resistance, and/or more repetitions per set, and/or increasing frequency is recommended.

Further remarks and caveats

• Be aware that there is considerable variability in individual responses to a standard dose of exercise. However, it is still reasonable to take the recommendations given above as a starting point and, if necessary, adapt the exercise to one’s own preferences and needs.
• Exercise is important for health – but it’s not the whole picture. Adequate nutrition and sleep are also important as well as professional medical attention where needed.
• There seem to be relevant sex differences in some responses to exercise. The recommendations presented above, however, should be appropriate for men and women.
• Warm-up, cool down, flexibility exercise, and gradual progression of exercise volume and intensity may reduce the risk of cardiovascular disease events and musculoskeletal injury during exercise.
• Supervision by an experienced health and fitness professional can reduce risk and enhance exercise adherence.
• Moderate-intensity (instead of high intensity) exercise that is enjoyable can enhance the affective responses to exercise and may improve adherence.

Two practical examples of a sufficient exercise routine

• Marie commutes daily by bicycle to the chemistry lab where she works. One way takes her ~15 minutes. On top of that, on Tuesday evening and on Saturday morning, Marie visits the “Bodypump” group fitness class in her local gym with her friend Rosalind.
• Albert goes to the gym twice a week. There he does a 10 min warm-up on the rowing machine followed by a strength training session (to which he was initially introduced by a fitness professional) that involves all major muscle groups (3 hard sets of 8 reps each). He walks to the gym, which takes him 20 min per way. Additionally, he jogs for 60 min with his friend Charles every Sunday.

Conclusion

I have presented arguments as to the necessity of physical exercise for health and productivity. Moreover, I have listed the evidence-based recommendations on exercise for health and I have provided specific examples.

I am confident that EAs can rely on these recommendations and do not themselves have to screen the jungle of often not well-founded advice on the internet.

Please let me know what you think in the comments - and where you might need more advice.

With all this in mind: Have a good workout!

Footnotes

[1] The cardio intensity recommendations that I use are expressed as subjective ratings of perceived exertion: On a scale of 0 to 10 (where sitting is 0 and the highest level of effort possible is 10) low-intensity is below 5, moderate-intensity activity is a 5 or 6, vigorous-intensity is a 7 or 8 and high-intensity is above 8.

[2] Intensities for resistance exercise are expressed as percent of the “1RM” (one repetition maximum) – the maximum weight a person can lift in one single repetition of the respective movement.

References

The arguments and recommendations presented are based on these articles:

• Chang, Y. K., Labban, J. D., Gapin, J. I., & Etnier, J. L. (2012). The effects of acute exercise on cognitive performance: a meta-analysis. Brain research, 1453, 87-101.
• Garber, C. E., Blissmer, B., Deschenes, M. R., Franklin, B. A., Lamonte, M. J., Lee, I. M., ... & Swain, D. P. (2011). Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise.
• Klika, B., & Jordan, C. (2013). High-intensity circuit training using body weight: Maximum results with minimal investment. ACSM's Health & Fitness Journal, 17(3), 8-13.
• Piercy, K. L., Troiano, R. P., Ballard, R. M., Carlson, S. A., Fulton, J. E., Galuska, D. A., ... & Olson, R. D. (2018). The physical activity guidelines for Americans. Jama, 320(19), 2020-2028.
• Sjøgaard, G., Christensen, J. R., Justesen, J. B., Murray, M., Dalager, T., Fredslund, G. H., & Søgaard, K. (2016). Exercise is more than medicine: The working age population's well-being and productivity. Journal of Sport and Health Science, 5(2), 159-165.
• World Health Organization. (2010). Global recommendations on physical activity for health. World Health Organization.