by Craig Liebenson

Over the last 50 years modern life has become primarily sedentary. Physical inactivity causes as much mortality as does smoking. With only 15% of our population meeting the World Health Organization’s (WHO) Physical Activity Guidelines (PAGs), addressing the inactivity crisis has become a major public health issue. Physical inactivity has many drivers – increased motorized transportation, prolonged static work postures and lack of green spaces as examples. Along with increased consumption of processed food and calories, the combination of moving less and eating more is a “double whammy” – increasing diabetes, obesity, heart disease, metabolic syndromes, neurodegenerative conditions (e.g. dementia and Alzheimer’s disease), osteoporosis and more. What can be done to bring physical activity back into our lives?

Our ancient ancestors from prehistory conserved energy for the inevitable hunting and gathering required for survival. Genetically we are programmed not only to rest, but to crave food. This survival programing, when combined with the easy access to refrigerated, processed and fast foods; sedentary occupations and transportation, has brought us to where we are today – diabetes rates skyrocketing from 1% to 10% in 100 years; obesity at an precedent 30% while steps a day on average have declined from approximately 18,000 steps a day to one third of that. 

Ironically, people are living longer – thanks to reduced infant mortality and modern medical marvels such as in our emergency rooms. Yet, we are “older younger”, so our health span is less even while our life span has increased dramatically. Fortunately, there are some simple measures that can help us increase our physical activity (PA). 

Three Steps to Take
According to the WHO, 3 physical activity targets are necessary to significantly improve our health: 

1. 150 minutes per week of aerobic exercise
2. 2x per week strength training
3. Avoidance of prolonged sitting or standing
4. Aerobic exercise
   30 minutes per day for 5 days per week achieves the 1st WHO PAG. This is by far the most important for its potent effect on reducing cardio-vascular disease. Any activity which gets your heart rate up will suffice. Simply “huff & puff”. This can even occur in installments such as climbing stairs or any 10 minute interval.
5. Strength training
   2 times per week strength training involves progressive resistance exercise of the major muscle groups of the body (arms, trunk, legs). Resistance should be sufficient to gradually increase the effort required to complete a set of repetitions. These fatiguing repetitions should be stopped just short of failure – typically a set should be stopped with 1-3 repetitions in reserve (RIR) before “failure”. A good rule of thumb is an appropriate weight should be “tough at ten” reps. 
6. Avoiding prolonged sedentary postures
   Getting up every hour or two is optimal. Micro-breaks of brief walking is all that is necessary. Getting up for 15 minutes every hour is recommended for “active recovery”, even with just a light stroll. This will help your metabolic health and reduce the risk of Type 2 Diabetes.

How Will You Benefit?
People exercise for different reasons: to lose weight, get stronger or improve their overall health being a few of them. Meeting the WHO PAGs lowers your risk of “all-causes” (cancer, heart disease, etc) mortality by about 40%. Even if you only meet the aerobic guidelines you lower your risk by 29%. Meeting the aerobic guidelines is associated with a lower risk of metabolic diseases such as type 2 diabetes mellitus, all-cause mortality, cardiorespiratory disease and coronary heart disease related mortality. 

Muscle mass begins to reduce after the age of 30 and becomes measurable in the 4th decade, decreasing at nearly 1% a year. By the age of 60 we lose 1.5% a year which increases fall risk. As we age our decreases in strength and power occur many times faster than the loss of muscle mass. This leads to functional impairments and heightened fracture and frailty risk.  

Figure 1
Summary of reduced risk of all-causes mortality associated with meeting the PAGs (Zhao). 
Strength training – 11% lower risk 
Aerobic training – 29% lower risk
Both strength & aerobic training – 40% lower risk

What Are Your Goals?
If we want to be above average 90 year olds we won’t get there if we are average 50 year olds. What are your goals? Let’s look at a few and how PA influences your likelihood of achieving these goals.

a) Cardio-Vascular Health
Cardio-vascular disease is our #1 killer. A number of tests such as blood pressure, cholesterol, HDL/LDL ratio, triglyceride count, resting heart rate and VO2 max are excellent metrics of heart health. 

“V02 max is the maximum amount of oxygen your body can utilize during exercise. It is a standard measure of aerobic fitness. Specific aerobic training methods can increase this number significantly. Compared to those in the highest 2.5% V02 max category, those in the lowest 25% category are 5 times more likely to die over 10 years. There is practically NOTHING in medicine that results in this magnitude of a survival advantage.” Paddy Barrett, M.D, (2022). 

Once we realize that our ability to function independently is directly related to how active we are, it is easy to conceptualize the value of staying active and training for the game of life. Specifically, to keep our biological age lower than our chronological age. This can be detailed in terms of specific goals or targets we’d like to maintain as we age, such as:

• To briskly climb stairs
• Walk 3 mph up slight incline (5% grade)
• Walk 3 mph on flat ground

Figure 2
According to neuroscientist Louisa Nicola, to build your VO2 max, 80% of your aerobic training sessions should be low-intensity (challenging but conversational). The popular interval training does not build this base and should be avoided by people just starting to become active. While for those who build a solid aerobic base in low intensity training (often called Zone 1-2 training) it can be added and performed 1-2x per week at most for at least 6 months. 

b) Body Composition
To gain lean muscle mass, “Participation (>2 years) in either aerobic, resistance, or tai-chi exercise was linked to higher lean mass and lower body fat than sedentary controls…As little as 60 min per week had similar benefits to much higher ‘doses’.” (Leong, 2023).

Insulin sensitivity and impaired glucose tolerance can be mitigated with increased PA, “a direct link between physical inactivity and visceral fat has been established”. Decreasing your steps per day from 10,000 to 1500 after just 2 weeks was shown to impair glucose tolerance as well as postprandial lipid metabolism. A 7% increase in intra-abdominal fat mass, visceral adipose tissue increases, and BMI decreased. (Pedersen, 2019). 

c) Healthy Longevity
Women in particular benefit from increased aerobic and resistance training activity. Falls, fractures and frailty are major killers over the age of 65. Post-menopausal hormonal shifts accelerate losses of bone density (osteoporosis) and, according to neuroscientist Louisa Nichol, “loss of muscle and bone mass is arguably the greatest potential threat to vitality and independence in the aging female population”. Here is a chart with sample exercises to build muscle mass and strength necessary to prevent falls, fractures, and frailty (Devries, 2023). 

Figure  3
Single leg standing balance is a key functional capacity that correlates with this. 20% of people in their early 60s can’t stand on one leg for 10 seconds. 50% of 70 year olds. 90% of 80 year olds. (Araujo, 2022).

Figure 4
If you could perform the 10 second single leg balance test, the probability of you being alive seven years later is over 90%. If you can’t, it’s only 65%.

Why Is It So Hard to Sustain New Physical Activity Habits?

There are many reasons why, in spite of the obvious benefits of PA, so few people avoid a sedentary lifestyle:

• Social constraints (cities built for cars instead of pedestrians or bikes; lack of green spaces, safety, etc). 
• Lifestyle factors (home and work stress, lack of sleep, not enough time, etc.)
• Embodied beliefs (being told certain fear producing narratives such as hurt = harm, that you have a diagnosis of arthritis – eg wear & tear, you’re out of alignment or have postural or movement dysfunctions that need to be “corrected”, etc.)

Nobody should feel that they are lazy or weak if they are not more active. World PA and health experts are focusing more attention on simple messages like “Every Move Counts”. Yes, more is usually better but the biggest gains accrue when a person shifts from being sedentary to becoming more active. As an example, walking 10,000 steps per day is more beneficial than walking 5,000. But the health benefits of a bump in volume from 2500 steps to 5000 steps is far greater, so one should never feel it’s NOT worth it to make small changes!

Figure 5
“There is no threshold that must be exceeded before benefits begin to accrue; the accrual is most rapid for the least active individuals. Sedentary time is directly associated with risk of all-cause & CV mortality, incident CV disease, type 2 diabetes, & selected cancer sites.”

“Compared with the least (1895 steps), the first quartile (4000 steps) had a 37% lower risk for all causes of death (HR = 0.63, 0.57-0.71)”. Since the World Health Organization has promoted “Every Move Counts”, the biggest net improvement in health comes from simply avoiding being sedentary and STARTING to get active. This is a very important message since many people believe if they don’t do MORE it’s not worth doing ANYTHING (WHO 2020).

Dose-response association between the daily step count and all-cause mortality: A systematic review and meta-analysis (Liu).

Figure 6
It’s not only the volume of activity, but the duration that matters. While accumulating long bouts of aerobic training  has great value, even just performing short “movement snacks” of just 10 minutes  duration has great utility (Chastin).  

Aerobic Training Made Simple
Low intensity aerobic exercise short of the fatigue threshold has potent benefits. This form of exercise used to be called Long Slow Duration (LSD) training, low intensity training (LIT) or what is now popularly called Zone 2 training. According to Alan Couzens, (PhD, 2023), the health and performance benefits include improving one’s:

• Aerobic capacity 
• Resting heart rate
• Recoverability
• Metabolic flexibility
• Mitochondrial density
• Fat burning (fuel partitioning)

“Unfortunately, many novice athletes barely train or are prescribed zone 2 training. Therefore, they don’t develop a good “base”, thinking that the only way to get faster is by always training fast. Doing this won’t (lead to) improve(ment) nearly as much as if they trained Z2 in large amounts.” Louisa Nicola, (PhD, 2023)

“The misconception that you need to be exhausted, sweaty and breathless to gain benefits from exercise is probably the greatest prevailing exercise myth that exists today and it leads many gym goers chasing fatigue instead of real progress.” Kevin Carr (2022).

“Group exercise classes (Peloton, Soul cycle, orange theory) tend to have the everyday person train too hard. Why? People judge the value of the workout based on their effort. Sweat and hard work = good workout. Most training should be pretty comfortable, but easy doesn’t sell.” Steve Magness, author, Do Hard Things (2022).

How do you know if you’re performing your aerobic activity at a low enough intensity to build a base of aerobic capacity? According to Siren Seiler (2023), “Recently I have been checking that I really am at “talking pace” by speaking out loud in full sentences during long LIT rides on my trainer. I hope the neighbors cannot hear me because they probably already think I am pretty weird”. Others say maintain a pace where you can speak but not while chatting endlessly. Some offer the guideline that you should be able to breathe exclusively through your nose. 

According to Gordo Byrn (2022), “Why Focus on Easy Pace”? 

• Because you might not have it 
• Because your easy capacity indicates your likely stamina at higher intensities
• Because your easy fitness is what enables you to absorb, and recover from, all training

When you have a strong aerobic foundation, you can burn more fat via fat oxidation and delay tapping into glucose stores which lead to lactic acid build up and insulin sensitivity. 

Strength Training Made Simple
When it comes to strength or resistance training (RT) minimal-dose approaches have the potential to minimize various barriers to participation and may have positive implications for the feasibility & scalability of RT.

“…brief but frequent minimal-dose RT approaches (i.e. resistance ‘exercise snacking’) may provide additional benefits for interrupting sedentary behavior patterns associated with increased cardiometabolic risk. Compared to traditional approaches, minimal-dose RT may also limit negative affective responses, such as increased discomfort & decreased enjoyment, both of which are associated with increased training volumes & may negatively influence exercise adherence.” (Fyfe, 2021)

As an alternative to performing strength training 2x per week, you can spread out your sets across the week. Here is a guideline, “Regarding weekly training volume, current guidelines recommend performing 2–4 sets per muscle group for 2–3 times a week, which corresponds to a weekly training volume of 4–12 sets per muscle group.“ (Iverson, 2021)

Assuming you are performing the following 6 patterns – upper body push (overhead)/pull/press (horizontal)/carry and lower body squat/hinge that means just 6 X 4 or 24 sets of progressive RT each week can build muscle mass, strength and power (see Figure 2). 

Game Plan for Lifestyle Change
A popular myth is that exercise has to be long duration or high intensity. In fact of the three variables – frequency, duration, intensity – it is frequency that is the first level to pull. So frequent “micro-breaks”, or, “movement snacks” can be used to perform recovery, easy or steady aerobic activity, as well as resistance training snacks. 

Think of the following guidelines: 

1. Get up for 15 minutes every hour of sitting or standing and perform active recovery
2. Engage in easy & steady aerobic exercise (power walk, bike, hike, easy jog, swim, ruck) for at least 30 minutes a day, 5 days a week. This is a pace where you can carry on a conversation. Easy being easy and steady being challenging. Heart rate should not go above 60-80% of your maximum. 
3. Engage in strength training either 2x/week or in exercise snacks for 5-8 minutes, 1-3x a day. These strength exercises can include weights or even bodyweight (push-ups, lunges, stair climbing). None of the resistance exercises should be to failure. This means you can perform your final repetitions with good form and without holding your breath or grunting. 
4. Perform high intensity interval training aerobic exercise at most 1x a week or perform a small volume of sprints 2x a week (5-8 reps). 
5. Perform sports you enjoy frequently (tennis, pickle ball, golf, soccer, etc)

References:
Araujo CG, de Souza E Silva CG, Laukkanen JA, Fiatarone Singh M, Kunutsor SK, Myers J, Franca JF, Castro CL. Successful 10-second one-legged stance performance predicts survival in middle-aged and older individuals. Br J Sports Med. 2022 Sep;56(17):975-980.

Barrett, Paddy, M.D. Twitter. (2022).

Chastin SFM, De Craemer M, De Cocker K, et al. How does Light-intensity physical activity associate with adult cardiometabolic health and mortality? systematic review  with meta-analysis of experimental and observational studies. Br J Sports Med  2019;53:370–6.  

Devries MC, Giangregorio L. Using the specificity and overload principles to prevent sarcopenia, falls and fractures with exercise. Bone. 2023 Jan;166:116573.

Fyfe, J.J., Hamilton, D.L. & Daly, R.M. Minimal-Dose Resistance Training for Improving Muscle Mass, Strength, and Function: A Narrative Review of Current Evidence and Practical Considerations. Sports Med (2021).

Iversen, V.M., Norum, M., Schoenfeld, B.J. et al. No Time to Lift? Designing Time-Efficient Training Programs for Strength and Hypertrophy: A Narrative Review. Sports Med 51, 2079–2095 (2021).

Leong LC, Swee KNL. The effects of community-based exercise modalities and volume on musculoskeletal health and functions in elderly people. Frontiers in Physiology. 14:2023

Liu Y,  Sun Z,(2022) Dose-response association between the daily step count and all-cause mortality: A systematic review and meta-analysis, Journal of Sports Sciences, 40:15, 1678-1687.

Pedersen BK. The Physiology of Optimizing Health with a Focus on Exercise as Medicine. Annu. Rev. Physiol. 2019. 81:25.1–25.21.

WHO. Every move counts: launch of the WHO guidelines on physical activity and sedentary behaviour Nov 26, 2020.

Zhao, M. Vetrank, S.P, Magnussen C.G, and X, B. Recommended physical activity and all cause and acute specific mortality in US adults: prospective cohort study. BMJ. 2020. 370.