Stay at home but keep on moving

Movement has been the key for survival of human beings since prehistoric times.
In our daily life we are used to moving to go to work, buy groceries, engage in sporting activities and socialising. As we do so we preserve the health of the muscular, cardiovascular, metabolic, endocrine and nervous systems, vital for the good functioning of the human body.

In fact, we are often reminded that we should not do less than 5,000 steps per day in order to avoid being sedentary and more than 10,000 steps per day to remain healthy. 

But what happens to the human body when daily movement is drastically reduced, as the number of  daily steps is reduced to well below 5,000 steps per day?
How much muscle mass, strength, cardiovascular and neurological function do we lose?
Most of all, what are the consequences on essential metabolic functions, such as glucose homeostasis by insulin and how important is to control diet to preserve muscle mass and prevent body fat gain?

The WHO has recognised chronic inactivity as the 4^th cause of global death: 1,6 Million people die prematurely every year due to insufficient physical acvity. How quickly do the negative effects of inactivity occur and what is the minimum amount of daily physical activity we should perform to offset them?

This is a very serious challenge that our modern societies are suddenly facing as entire populations have been rightly asked to self-isolate due to the Covid-19 outbreak and live in home-confinement for weeks, possibly months. This period of restricted movement, essential for avoiding further spreading of the virus, affects all citizens regardless of age, sex and ethnicity. In order to avoid mid-long term impacts – in terms of NCDs – generated by the sudden reduction of physical activity, it is important to promote home exercise to prevent people from adopting sedentary behaviours.

Many studies indicated that a direct relationship exists between sitting time and chronic health conditions in humans, a situation that is potentially exacerbated in these exceptional circumstances where people are confined at home and in many instances with no (or limited) access to a garden, let alone exercise facilities.

"As scientists, expert in human and applied physiology, endocrinology, internal medicine, exercise, metabolism and nutrition, we feel a duty to explain the risks of sedentarism on the human body and formulate recommendations on the physical and nutritional interventions we can adopt to prevent/mitigate the adverse effects associated with home-confinement with the overall aim of preserving a healthy status."

Scientists' commitment

Our first goal is to produce a White Paper based on objective, state-of-the-art knowledge of the impact of inactivity as well as of reduced mobility on muscular, cardiovascular and metabolic health.

Our second, but equally important goal, is to formulate, through the White Paper, recommendations on practical and effective exercise and nutritional interventions that should be adopted by individuals, and endorsed by wellness organisations, to combat the adverse consequences of inactivity imposed by long-term periods of home-confinement.

Marco Narici, Professor of Physiology, University of Padova, Italy
Giuseppe De Vito, Professor of Physiology, University of Padova, Italy
Antonio Paoli, Professor of Exercise and Sport Sciences, University of Padova, Italy
Martino Franchi, Researcher in Physiology , University of Padova, Italy
Bruno Grassi, Professor of Physiology, University of Udine, Italy
Gianni Biolo, Professor of Internal Medicine, University of Trieste, Italy
Flemming Dela, Professor of Pathophysiology, University of Copenhagen, Denmark
Paul Greenhaff, Professor of Muscle Metabolism, University of Nottingham, United Kingdom
Constantinos Maganaris, Professor of Musculoskeletal Biomechanics, Liveropool John Moores University, United Kingdom

IMPACT OF SEDENTARISM DUE TO THE COVID-19 HOME CONFINEMENT ON MUSCULAR, CARDIOVASCULAR AND METABOLIC HEALTH: PHYSIOLOGICAL AND PATHOPHYSIOLOGICAL IMPLICATIONS AND RECOMMENDATIONS FOR PHYSICAL AND NUTRITIONAL COUNTERMEASURES

Exercise is music for your muscles, don’t stop playing as they are still listening

Friday 10th of April More than 1.000 people participated to a Webinar entitled: ‘Recommendations for physical and nutritional countermeasures to counteract forced sedentarism’ organized by Technogym with the support of the European College of Sport Science.

A group of scientists presented state-of-the-art knowledge of the impact of inactivity and provided recommendations on practical and effective exercise and nutritional interventions that should be adopted to combat the adverse consequences of inactivity.
The group, lead by Prof. Marco Narici will shortly publish a paper based on objective, state-of-the-art knowledge of the impact of inactivity as well as of reduced mobility on muscular, cardiovascular and metabolic health.

Their second, but equally important goal, is to formulate, through the White Paper, recommendations on practical and effective exercise and nutritional interventions that should be adopted by individuals, and endorsed by wellness organizations, to combat the adverse consequences of inactivity imposed by long-term periods of home-confinement.

Prof. Narici presented the evidence showing that exercise is of vital importance for preserving muscle mass, particularly of the antigravity muscles that are constantly used for sustaining an upright posture, and the integrity and function of the neuromuscular system. There is now in fact increasing evidence that chronic inactivity, triggers muscle fiber denervation and damage to the neuromuscular junction.

Hence, when facing period of restricted activity due to home confinement as in the present Covid-19 pandemic, the main recommendation for preserving neuromuscular health is to exercise daily with slow, medium-intensity contractions and perform aerobic exercise workouts involving large muscle groups. He concluded saying: “Remember that exercise is music for your muscles, don’t stop playing as they are still listening!”

Prof. Greenhaf explained how the maintenance of muscle mass is dependent on the balance between rates of muscle protein synthesis and muscle protein breakdown, where a chronic imbalance results in either the loss or gain of muscle mass. Thus, suppression of muscle protein synthesis during immobilization or extremely low physical activity is the primary driver of muscle mass loss in humans. However, there are studies that highlight the effectiveness of muscle contraction as a countermeasure to prevent muscle loss during immobilization and inactivity, and also to increase muscle mass restoration following prolonged periods of inactivity or immobilization.

Even if the molecular mechanisms by which exercise exerts such positive effect(s) remain unknown,  such insight would greatly help our understanding of how to maintain muscle mass and metabolic health in future public health crisis requiring social distancing and isolation.

Prof. Dela covered another important aspect: the consequences of inactivity on glucose homeostasis. He explained the central role of skeletal muscle in inactivity induced insulin resistance,

were the mechanisms behind the inactivity induced decrease in whole-body insulin sensitivity and impaired glucose tolerance are coupled to changes within the skeletal muscle. With inactivity there is also an impairment in skeletal muscle metabolic capacity with a decrease in GLUT4 transporter protein content and glycogen synthase activation. However, even if that the time-course of inactivity induced metabolic dysfunction appears to be far quicker than the positive impact of increasing physical activity levels, in the times of restrictions due to the COVID16 pandemic it is important to realize that even a modest amount of moderate-intensity daily exercise (equivalent to 30 min per day) is necessary. Any addition to this minimal regimen will lead to improvements in many health measures.

Prof. Grassi focused his intervention in explain what happens to the cardiorespiratory system with inactivity. The decrease of V̇O2max, the most important index of cardiorespiratory fitness (and health) is linear and similar to what happens with bed rest studies. It is also reasonable to assume that also during a period of forced inactivity, the V̇O2max decrease would be more pronounced in the elderly with respect to younger counterparts.

VBesides being one of the main determinants of exercise tolerance, V̇O2max is considered an index of “cardiorespiratory fitness”. As such, V̇O2max is a more powerful predictor of mortality than other established risk factors for cardiovascular diseases. For that reason it is fundamental to preserve cardiorespiratory fitness.

A threshold of ~4,500-6,000 steps/day has been identified as the minumum to avoid to incur in an increased cardio-metabolic risk. However the vagueness of these recommendations, together with the extraordinary burden of physical inactivity put on hundreds of millions of people by the COVID-19 pandemic, stress the need for more research on the topic.

Prof. Paoli, after confirming that obviously the best countermeasure to physical inactivity is trying to be active, he pointed out that it is also of paramount importance to modulate the diet to fit the new physical activity context.
In general, many studies provide strong bases for amino acids/protein supplementation in older adults but anyhow, in older healthy adults and healthy adults the ability of amino acids/protein supplementation to improve muscle mass/function is related to the amount and the kind exercise performed.

Subjects requested to stay at home during this time of social distancing and isolation should modify their diet according to the reduced energy expenditure (up to 35-40%), reducing the total energy intake by a similar amount. It is important to refrain from multiple snacks during the day (nibbling), if not well controlled, this behavior risks to increase daily energy intake. In addition, in this period, social distancing, isolation and concerns about COVID-19 may increase depression, anxiety and boredom all related to an increase of energy intake; thus it would be helpful to maintain 2-3 meals per day, with a long overnight fast. In these strange times that reflect some life habits of the medieval period, it may be useful to follow this 12th century recommendation: “Eat like a king in the morning, a prince at noon, and a peasant at dinner”

KEEP MOVING EVERYDAY

These are hard times for all of us.
Many governments around the world are implementing strong movement restriction measures to prevent and limit the virus spread. In many countries people are forced to stay at home for weeks or even for months.
It is important to follow those citizenship guidelines to overcome the emergency as soon as possible, but at the same time it’s important to avoid becoming sedentary in order not to incur in health problems in the mid-long term.
Many studies indicated that a direct relationship exists between sitting time and chronic health conditions and the World Health Organization clearly indicates physical inactivity as the cause of many serious diseases, to the point that long-term physical inactivity has been ranked as the 4th cause of premature death.
Just four points to consider:

1. Stay active! Up to one hour a day of moderate to vigorous exercise is proven to boost your immune system. It can be aerobic or resistance exercise
2. Sleep well! Go to bed and wake up following a regular pattern and allow to your body to have 7 hours of sleep
3. Eat properly! A good diet should include raw cereals, vegetables, legumes and fruit. Limit as much as you can processed food, sugars and animal proteins
4. Relax and be positive! Stressors can negatively affect your immune defense through the autonomic nervous system. Deep breathing, mindfulness and yoga can do a lot to reduce anxiety

All in all, our body is a terrific defense, we just need to know how to use it in the best way.
Stay healthy, stay active.