Obesity – A Greater Risk of COVID-19 Severity?

As we all are aware of the current pandemic situation caused by Covid-19 has attracted worldwide attention. Usually, obesity has many side effects which complicates our physical and mental well-being. Obesity boosts the severity of respiratory diseases, but this is still not clear whether this plays a role in having a greater Covid-19 severity of illness.

For this purpose, a study was conducted in Asia where seventy-five patients diagnosed as ‘obese’ and seventy-five ‘non-obese’ took part, all of them having Covid-19. The severity of Covid-19 was assessed during hospitalization also, obesity was defined as BMI ≥25 kg/m2 in this Asian population. All patients denied a history of active cancer, chronic obstructive or restrictive pulmonary diseases, or other end-stage diseases.

The study has shown association between obesity and higher risk of having severe Covid-19. Each 1-unit increase in BMI was also associated with a 12% increase in the risk of severe COVID-19. To date, the virologic and physiological mechanisms underlying the strong relationship observed between obesity and COVID-19 severity are poorly understood.

It is reasonable to hypothesize that more severe COVID-19 in patients with obesity may be the consequence of underlying low-grade chronic inflammation and suppression of innate and adaptive immune responses.

Also, the mechanical dysfunction caused by obesity can increase the severity of lower respiratory tract infection and contribute to secondary infection. Health care professionals caring for Covid-19 patients should be aware of the likelihood of severe Covid-19 in obese people. Thus, the presence of obesity carries higher risk of severe illness roughly threefold with a consequent longer hospitalization.

On the other hand, the relationship between socioeconomic status and risk of obesity, and the political interventions such as lockdown against Covid-19 might translate into increased obesity occurrence and metabolic diseases in inactive groups and lower socio-economic status.

A reason for this increase is the availability of highly processed, energy-rich, cheap foods which boosts the calorie intake beyond energetic needs, which such foods are preferred and selected by individuals with a lower socioeconomic status who have limited income resources.

The use of lockdown to combat Covid-19 has been successful to a certain extent from an epidemiological perspective, but lockdowns have had negative effect on metabolic health. On the other hand, approaches designed to contain the spread of Covid-19 might promote obesity and associated metabolic diseases.

Accordingly, when considering the use of lockdowns in the future, the potential adverse consequence on metabolic health should be taken into consideration. Also, if potential lockdowns are to occur, the closure of Sporting facilities such as gyms should remain open with caution, which will potentially help people cope with inactivity.


Clemmensen, C., Petersen, M. B., & Sørensen, T. I. (2020). Will the COVID-19 pandemic worsen the obesity epidemic?. Nature Reviews Endocrinology16(9), 469-470.

Dixon AE,  Peters U. The effect of obesity on lung function. Expert Rev Respir Med 2018;12:755–767 Saltiel AR, Olefsky JM. Inflammatory mechanisms linking obesity and metabolic disease 2017

Gao, F., Zheng, K. I., Wang, X. B., Sun, Q. F., Pan, K. H., Wang, T. Y., … & Zheng, M. H. (2020). Obesity is a risk factor for greater COVID-19 severity. Diabetes care, 43(7), e72-e74.

World Health Organization Rolling update on coronavirus disease (COVID-19): WHO characterizes COVID-19 as a pandemic. Published 11 March 2020.

COVID-19 and Body Mass

Unfortunately at this point the majority of scientists agree upon the fact that Covid-19 has become, and will be a part of, our reality for many months if not years to come. During this period, as a society we have been learning and adapting to new measures in our fight against the disease. Quarantines, social distancing, sanitizers in many shapes and forms, as well as some bogus anti-Covid ‘supplements’ are the first ones that come to mind in this long list.

However one of the more significant details that has been recently revealed in numerous research studies is the undeniable connection between an individual’s physical fitness and the severity of Covid-19 disease. To be more exact it is the connection between BMI (Body Mass Index) and the severity of Covid-19 symptoms an individual experiences. And outcomes of these studies indicate that the higher one’s BMI the stronger and fatal the disease becomes.

You might be asking what it is that is causing this adverse reaction to Covid-19 in overweight/obese populations. Stephen O’Rahilly, director of the Medical Research Council’s Metabolic Diseases Unit at the University of Cambridge says “Two things happen when obesity occurs: the amount of fat increases, but also you put fat in the wrong places. You put it in the liver and in skeletal muscle. And that disturbs metabolism. The key disturbance is that you get very high levels of insulin in the blood.”

And he suggests that it is this disturbance that leads to a wide range of abnormalities such as increases in inflammatory cytokines as well as a reduction of adiponectin, a molecule that directly protects the lungs. Stephen O’Rahilly adds that it is also possible that fat could be increasing in the lung itself, which may lead to complications in how the lung handle the Covid-19 virus.

So far studies in the United States have indicated that having a BMI over 30 – a BMI above 30 indicates obesity- increases the risk of being admitted to hospital with Covid-19 by 113%; of being admitted to intensive care by 74%; while increasing the risk of death by 48%. On top of that Public Health England’s report suggests that the increase in risk of death rises by 90% in people with a BMI above 40.

What’s even worse is that these numbers are irrespective of age, as extra weight and obesity tend to affect younger populations just as bad. According to World Obesity Federation people under the age of 60 with a BMI between 30-34 are statistically twice as likely to be admitted to intensive care than those with a lower BMI.

Public Health England also warns that the risk of developing serious disease due to Covid-19 among people from black, Asian, and minority ethnic groups is 2.56 times higher than among white Europeans,. However at a BMI of 25 there is no such difference to be observed between ethnicities.

Considering that obesity is one of the biggest health problems that the UK is currently facing with two-third (63%) of its adult population being overweight and/or obese, this should be seen as a major concern as well as a call for action. We have to understand that avoiding contact with the virus is one part of the battle.

Being prepared for the infection is another part. And knowing that excess weight is a modifiable risk factor, improving your physical fitness is one of the smartest steps you could be taking right now. In addition to becoming more Covid-proof you will also be looking better!

Aydin Parmaksizoglu

BMI Formula: weight (lb) / [height (in)]2 x 703


GOV.UK. 2021. Excess weight can increase risk of serious illness and death from COVID-19. [online] Available at: <https://www.gov.uk/government/news/excess-weight-can-increase-risk-of-serious-illness-and-death-from-covid-19&gt; [Accessed 8 June 2021].

Mahase, E., 2020. Covid-19: Why are age and obesity risk factors for serious disease?. BMJ, (371), p.m4130.

Senthilingam, M., 2021. Covid-19 has made the obesity epidemic worse, but failed to ignite enough action. BMJ, p.n411.

Williamson, E., Walker, A., Bhaskaran, K., Bacon, S., Bates, C., Morton, C., Curtis, H., Mehrkar, A., Evans, D., Inglesby, P., Cockburn, J., McDonald, H., MacKenna, B., Tomlinson, L., Douglas, I., Rentsch, C., Mathur, R., Wong, A., Grieve, R., Harrison, D., Forbes, H., Schultze, A., Croker, R., Parry, J., Hester, F., Harper, S., Perera, R., Evans, S., Smeeth, L. and Goldacre, B., 2020. Factors associated with COVID-19-related death using OpenSAFELY. Nature, 584(7821), pp.430-436.

World Obesity Federation. 2021. Obesity and COVID-19: Policy statement | World Obesity Federation. [online] Available at: <https://www.worldobesity.org/news/obesity-and-covid-19-policy-statement&gt; [Accessed 8 June 2021].

The Vegan Diet: An Introduction

The vegan diet is an entirely plant based diet, which in other words means that products that contain animal products such as meat, eggs and dairy are not consumed at all. Research suggests that people who are following vegan diet are tending to have a lower body mass index (BMI). This indicates that vegan diet aids with weight loss, also people who are vegan are more likely to make weight-conscious decisions.

Some studies have examined the effect of different diets such as vegan, vegetarian, semi-vegetarian, and omnivorous diet on weight loss. The results concluded that the group of people on vegan diet lost the more weight compared to other diets and also their saturated fats consumption has decreased.  Another study examined vegan and vegetarian diets, which has shown that plant-based diets were more effective for weight loss accompanied with health improvements such as lower cholesterol and decreased risk of cancer, compared to omnivorous diets.

Following the vegetarian or vegan type of diet has been shown to boost metabolism, which means that more calories could be burned while at rest, making weight loss more effective. Therefore, following vegan diets has shown to have many health benefits. This means that people consume less processed or pre-packed food that contain animal products, which eventually allows them to consume fresh and whole foods instead.

The following of plant-based diet or vegan diet is associated with lower risk of cancer, reduced risk of stroke, reduced inflammation, lower cholesterol, lower risk of diabetes and lower blood glucose. On the other hand, it may also have its cons when adhering to vegan diet. Animal products naturally contain vitamin-B12, which means that it has to be supplemented or find other sources. There is potential for vegans to become deficient in iron, vitamin C, calcium, vitamin D, protein, and omega 3, if foods containing all these are not consumed.

It is important to mention that for every diet, the key to successful weight loss is to consume lesser calories than are burned when exercising or doing daily activities. People that want to lose weight using vegan diet should consume mainly fibre-rich fruits e.g. berries, apples, citruses and others; also fibre rich and leafy vegetables such as broccoli, potatoes, sprouts, spinach, kale; fats coming from avocado, olive oil, nuts & seeds; protein sources should be mainly coming from tofu, soy, soy milk, beans, lentils, seitan, tempeh; whole grains such as oats, brown rice, quinoa, wholegrain bread.

On the other hand, people who want to be vegan and lose weight should avoid processed meat substitutes, vegan deserts, and processed snacks as some of them contain high amounts of sugar and saturated fats. Following plant-based diet has its positives from the perspective of consuming more plant foods, probiotics and fibres.

However, this can be healthy lifestyle diet and can be used for weight loss as well, but individuals taking this approach should be cautious of the deficits of some vitamins and minerals that are absent in vegan diet. Some nutritional deficits can be replenished by using vegan supplements, otherwise the lack of macronutrients and micronutrients may lead to disruptions in homeostasis.



Dinu, M., Abbate, R., Gensini, G. F., Casini, A., & Sofi, F. (2017). Vegetarian, vegan diets and multiple health outcomes: a systematic review with meta-analysis of observational studies. Critical reviews in food science and nutrition57(17), 3640-3649.

Turner-McGrievy, G. M., Davidson, C. R., Wingard, E. E., Wilcox, S., & Frongillo, E. A. (2015). Comparative effectiveness of plant-based diets for weight loss: a randomized controlled trial of five different diets. Nutrition31(2), 350-358.

An Introduction to the Keto Diet

Lets begin with introducing what is ketosis and how to achieve this state. Well, Ketosis is a condition where your Ketones levels are high within your body. These molecules (Ketones) can be seen as alternative fuel for your body, and usually this alternative fuel is used by many organs in the body when its necessary.

Perhaps many of you know that the body is counting on three main macro nutrients as fuel source such as the carbohydrates, protein, and fats. Mainly, the carbohydrates and fats are the primary energy sources, and the protein is utilised as well but in lesser degree.

However, once in the blood stream these macro nutrients get processed and they are broken down to their simplest building blocks, in other words carbohydrates are broken down to glucose, fats to fatty acids, and protein to amino acids.

Mostly, the body uses glucose as well as fatty acids as energy fuel, but our brain relies only on glucose due to the fact that fatty acids cant diffuse into the brain. But in many circumstances such as being in fasted state, our body has a deficit of glucose which eventually our body activates its mechanism to use ketones as alternative fuel.

In the classic Keto diet, the macro nutrients usually consist of 80-90% fats, 10-15% protein, and carbohydrates roughly 5%. You can consume these fats in different forms such as coconut butter/oil, olive oil, nuts, fatty fishes and others. The protein can be acquired through fatty meats and fish, and carbohydrates should be consumed from vegetables.

Usually prior to starting the diet, the body should be in fasted state for 1-2 days. This type of diet is used for therapeutically purposes, and strict control and calorie consumption monitoring is required. When used therapeutically, most people see effects after 2-3 months after its start.

Looking at Keto diet used in sports, its important to mention that there are many variations of the Keto diet and this type of diet is recommended to replace the medium-high carbohydrate consumption, in order to improve sporting performance.

Even though there are a lot of researches on Keto diet and also there is a lot of contradiction. Looking at offroad cyclists that were on Keto diet, it is observed improved VO2 max and the oxygen flow in VO2 Lactate Treshold. On the other hand, it is observed better results in power output in the group that was on consumption of normal quantity of carbohydrates (Zajac, A., et al., 2014).

In another research where keto diet was used by artistic gymnasts for 30 days, there is no difference in power output, but decreased weight loss and lower bodyfat % is observed (Paoli et, al., 2012). Most of the scientific data suggest that Keto diet has the following identical outcomes such as:

  • Low carbohydrate or ketogenic diet regimen can help the improvement of the body composition mainly through weight loss and the excess fats, but its not optimal for building muscle mass
  • When optimal sporting performance is pursued, including aerobic and anaerobic physical activity, it is necessary to consume atleast moderate quantity of carbohydrates.

To conclude this, it is important to state that the most important aspect of following a diet regime is to find out the most convenient, delicious and healthy way to adhere in order to achieve the desired goals.


Paoli, A., Grimaldi, K., D’Agostino, D., Cenci, L., Moro, T., Bianco, A., & Palma, A. (2012). Ketogenic diet does not affect strength performance in elite artistic gymnasts. Journal of the International Society of Sports Nutrition, 9(1), 1-9.

Zajac, A., Poprzecki, S., Maszczyk, A., Czuba, M., Michalczyk, M., & Zydek, G. (2014). The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists. Nutrients, 6(7), 2493-2508.

Paleo Diet: Genius or Fad?

What is it?

Paleo diet, also known as Paleolithic diet, caveman diet or stone-age diet is an approach to nutrition which mirrors the diet of our Paleolithic ancestors that inhabited the world between 2.5 million to 10.000 years ago.

Paleo diet typically consists of foods that could basically be either hunted or gathered in nature without the need of modern agriculture and farming. This includes lean meats, fish, eggs, fruits, some vegetables, nuts, and seeds. On the other hand the foods that are being avoided can be listed as , yet are not limited to, grains, legumes, dairy products, refined sugar, salt, potatoes, and any highly processed food

Why go Paleo?

The main purpose of this diet is to get rid of all the processed foods that are the staples of our modern western diets.  The reasoning behind it all stems from the fact that processed foods are usually denser in calories which makes it easier to put on weight while making it harder to feel full & satisfied, they are lower in micronutrients which may lead to nutritional deficiencies in the long run, and they also usually tend to be higher on the glycemic-index (especially processed carbohydrates) that can cause unwanted fluctuations in blood sugar levels.

There is also a common belief that the “Paleo foods” are the foods that we are evolved to digest better and thrive on. Considering that our ancestors were following a more physically active lifestyles and diets consisting of whole foods, the occurrence of our modern lifestyle diseases such as obesity, diabetes and heart disease was much lower. Therefore the expected health benefits of their diet can be listed as:

  • Weight loss
  • Improved glucose tolerance
  • Better blood pressure control
  • Lower triglycerides
  • Better appetite management

 What is it not?

It is most certainly not a magical diet where all you need to pay attention to happens to be just a list of foods to lose weight, and live forever. What diets like these cunningly hide from their following is that the foods that they are eliminating usually tend to contribute a high amount of calories to their standard diets in the first place. And by cutting out those foods, the total caloric intake will almost always be reduced to significant degree.

While for example diets such as low-carb or Keto remove carbohydrates that make up to almost 60% of total caloric intake on average, Paleo diet revolves around eliminating highly processed foods that are a lot higher in calories than most of the foods nature has to offer. And through this clever distraction people end up eating less than they would otherwise.

Another problem with such diets is that they tend to take their roots from any beneficial minor findings on the field of obesity research, and quickly turn them into a be all – end all marketing miracles. With Paleo diet come the new wave of packaged Paleo products which are most of the time not much different than what is already on the market yet have double the price.

Last but not least as romantic as it feels to follow the footsteps of our ancestors we also have to remember that human evolution did not stop in Paleolithic times, and we are still going through various adaptations to our environment and diet. With that said I hope that we can learn from our past, while avoiding to become a zealot for a certain diet.

Aydin Parmaksizoglu


Gunnars, K., 2018. The Paleo Diet — A Beginner’s Guide + Meal Plan. [online] Healthline. Available at: <https://www.healthline.com/nutrition/paleo-diet-meal-plan-and-menu#TOC_TITLE_HDR_12&gt; [Accessed 16 March 2021].

James, W., Johnson, R., Speakman, J., Wallace, D., Frühbeck, G., Iversen, P. and Stover, P., 2019. Nutrition and its role in human evolution. Journal of Internal Medicine, 285(5), pp.533-549.

McDonald, L., 2014. The Women’s Book: A Guide to Nutrition, Fat Loss, and Muscle Gain. 1st ed. Lyle McDonald.

Mayo Clinic. 2020. Paleo diet: Eat like a cave man and lose weight?. [online] Available at: <https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/paleo-diet/art-20111182&gt; [Accessed 16 March 2021].

Sweeteners: Friend or Foe?

Decades after their introduction to our diets there is still an ongoing debate whether sweeteners are harmful to our health or if they are simply a safe way to suppress your sweet cravings.

First things first we have to understand why it is considered beneficial for us to cut back on sugar, and before that we have to understand the big difference between various sources of sugar. Long story short when it comes to sugar it is all about how it is packaged. Sugars in the form of fruits come with a high fibre content (great for digestion), low glycemic index (meaning they do not cause sudden spikes in your blood sugar) and they provide you with lots of nutrients.

On the other hand the “evil sugars” come in processed forms such as chocolate bars, fizzy drinks, highly processed fruit juices, ice creams, and they are even added to products like soups, breads, etc. They have none of the beneficial stuff which we mentioned above, and they cause an unwanted spike in blood glucose which therefore raises your insulin levels (which eventually make it harder to burn off fat). They also increase triglycerides, cause inflammation in the body which then has the potential to lead to chronic illnesses such as diabetes and cardiovascular diseases.

How do sweeteners fair in comparison to sugar then? First of all I have to make it clear that most of the scaremongering claims root from animal studies where extremely high doses of these substances have been used. And believe it or not when it comes to human safety, animal studies are widely considered as a very poor source of information.

Also studies that claim a risk of obesity due to sweetener consumption tend to make the most common mistake of confusing correlation with causation. Most of the time it was not the sweetener that made the participants of these studies overweight but it was the overweight people consuming sweeteners with the aim of losing weight.

Whilst almost all the major health authorities in the world have agreed upon the safety of sweetener consumption, this should not “encourage” us to feast on sweeteners as they are still relatively new to our bodies, and there may still be more to discover over time. In the meantime I would not worry too much about an occasional can of a diet drink. At the end of the day it is usually the dose that makes the poison – you should consume what suits you in healthy moderation.


Coffee or No Thanks? A Look Into Caffeine and Sporting Performance

Caffeine is one of the most well known and studied supplement on the planet. It has many physiological effects although it has no nutritional value. However, its effects are associated with stimulating the nervous system and hence improving exercise capacity.  This ‘stimulant’ has been consumed worldwide for centuries and its effects are recognised by many nations. On the other hand athletes are among the groups of people who are interested in the effects of caffeine in endurance exercises and other physical activities.

The available literature suggests that the benefits of caffeine on performance athletes can be seen when moderate amounts of caffeine is consumed (~3mgkg1 body mass).  Also, these benefits are potential for many sports such as in endurance, high intensity activities, and stop-and-go events, there is not much evidence on its direct effect on strength and power activities.

Many studies using moderate to high doses of caffeine (5-9 mg/kg BM) have found ergogenic effects in endurance activities and recognised the effects on the physiological responses to exercise; this include increased heart rate, a doubling of blood catecholamine levels, higher blood lactate levels and also increased blood free fatty acid and glycerol levels in some subjects. On the other hand there are some side effects that could occur such as gastrointestinal upset, mental confusion, nervousness, impaired focus and sleep disturbances. Recent studies have shown that lower doses of caffeine can stimulate an ergogenic effect when consumed prior to exercise in short or long endurance events.

Some practical applications for athletes using caffeine can aid athletes in their performance goals. When considering whether to use caffeine as stimulant, it is recommended athletes to begin with low caffeine doses ~100-200mg, and if higher dose is consumed it does not appear to give additional advantage. However, the response to caffeine is strongly individual, and professional athletes need to see its effect in training before moving to competitions.

Caffeine’s ergogenic effect is independent of habitual caffeine use, training status, diet, gender, hydration status, and exercise modality, but results in the heat are less clear (see Burke et. al., 2013; Spriet, 2014). Also, caffeine can be found and consumed in the form of capsules, coffee, sports and energy drinks, gums, gels, and bars, but mouth rinsing with caffeine is less likely to produce an ergogenic effect. Even not so active individuals use caffeine containing substances in their everyday lives in order to improve their mental alertness or other uses such as pain killers.

Caffeine works by stimulating the central nervous system (CNS), heart, muscles, and the centres that control blood pressure. Caffeine can raise blood pressure, but might not have this effect in people who use it all the time. Caffeine can also act like a “water pill” that increases urine flow. But again, it may not have this effect in people who use caffeine regularly. Also, drinking caffeine during moderate exercise is not likely to cause dehydration.

Additionally, the research on caffeine have determined that lower dose of caffeine ~200mg is ergogenic in different exercise and sport scenarios in recreationally and well-trained individuals men and women. On the other hand, high caffeine doses are associated with unpleasant physiological responses to exercise and additional side effects and do not bring more benefits. The mechanism which explains the ergogenic effect of caffeine is shown from adenosine receptor antagonism in the central nervous system and the peripheral nervous system. However, the administration of caffeine in the form of capsules, tablets and coffee used in research, caffeine can be delivered in many different forms with similar ergogenic effects.

So, to wrap it up, caffeine consumption in normal quantity brings physiological benefits that could aid physically active individuals in their performance as well as not as active individuals in their everyday lives, but higher dose will not boost its effects and contrariwise it may cause adverse effects.



Burke, L., B. Desbrow, and L. Spriet (2013). Caffeine for sports performance. Human Kinetics, Champaign, Illinois, USA.

Spriet, L.L. (2014). Exercise and sport performance with low doses of caffeine. Sports Med. 44:S175-S184.

Importance of Post-Workout Nutrition

Many of us know how important the relationship between nutrition and sporting performance is. Usually the main goals of the post workout nutrition are to recover the body from the physiological stress that it went through and prepare it for upcoming activities. Post workout nutrition aims to replenish glycogen that was used during the workout, to stimulate muscle protein synthesis, reduce catabolic processes within the body, and reduce muscle fatigue and soreness.

Of course, the post workout nutrition consists mainly of protein, carbohydrates, and fats but also water, vitamins, minerals, electrolytes and all these nutrients can be consumed in the form of whole foods or supplements. However, the post workout nutrition depends on the goals of an individual. Keep in mind that post workout nutrition of a person who wants to lose fat is significantly different than the person who wants to pack on muscle mass, also their training programs will be individual too.

The post workout meal is all about replenishing what was lost during workout in order to optimize recovery process. Providing the body with the right combination of nutrients is essential for maximizing recovery. Some people prefer to take nutritional supplements to optimize recovery. However, according to a study on using carbohydrate & fat for training and recovery the only people who need to really concern themselves with immediately re-fueling, replenishing glycogen, post workout are those who may have another hard training session within an 8-hour window.

As we know intense workouts can cause break down of muscle protein, and studies have shown that consuming a protein and carbohydrate combination right after an intensive workout, can raise the insulin levels and blunt the effects of muscle protein breakdown. Also it is mentioned that this effect can be achieved by consuming well balanced meal 60+ minutes post workout. On the other hand, muscle protein synthesis is highly desired by many sporting individuals.

Studies suggest that an increase in essential amino acids in the bloodstream has great results on improving the rate of muscle protein synthesis, but other studies have found no significant change. However, another study points to a greater response when protein/carbohydrate is consumed up to 1 hour before workout, which makes sense as we consider the digestion time and the float of amino acid in the blood stream.

Also, another factor is the muscle hypertrophy which is an enlargement of the muscle tissue. Researchers suggest that hypertrophy can be greatly stimulated by consuming pre and post workout supplements. So a question might arise, “Do you need supplements immediately after workout?, according to studies is NO, unless your goal is to “bulk up” or you have multiple workouts in less than 8 hours frame during the day in order to optimize recovery.

Researches seems to support that you would be better off eating a protein / carbohydrate-based meal PRE- workout in order to blunt the effects of muscle breakdown, and promote glycogen replenishment, protein synthesis, and probably hypertrophy. But hey, it really comes down to your individual goals and training, be creative and find what works best for your body and goals. If you see your desired results, keep going with what you are doing, if not make some another changes and find your balance.

By Ibrahim


Burke, L., Kiens, B., & Ivy, J. (2004). Carbohydrates and fat for training recovery. Journal of Sport Sciences, 22, 15-30

Cribb, P., & Hayes, A. (2006). Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Medicine & Science in Sports & Exercise, 06, 1918-1925.

Newton, P. J. Post Workout Nutrition.

Stark, M., Lukaszuk, J., Prawitz, A., & Salacinski, A. (2012). Protein timing and its effects on muscular hypertrophy and strength in individuals engaged in weight-training. Journal of the International Society of Sports Nutrition, 9(54), 1-8.

Exercising On An Empty Stomach

Exercising early in the morning can be hard and this can be due to many reasons such as waking up earlier than you’d have liked to or due to the lack of energy that is coming from food in your system. However, it is debatable whether it is a good idea to workout on an empty stomach or if this fasted state is going to cause you adverse effects such as metabolic disbalance.

Let’s take for instance waking up in the morning after 6-12 hour overnight fast. This state will cause your body to somewhat deplete its glycogen and therefore activate the fat burning process by mobilizing the usage of fat as energy to compensate the low glycogen levels. However, as we know when we eat food, our body starts to produce insulin which interferes with the mobilization of body fat.

As the carbohydrates (in the form of glucose) levels are low in the blood stream caused by the overnight fast, more calories from stored fat are burned when exercising to compensate the low glucose levels. Therefore in fasted state less insulin is present which ultimately links to burn more calories that come from stored fats when you do cardio in such fasted state.

Doing cardio in the morning will allow your metabolism to remain high for a period of time after the workout is done and take advantage of the after-burn effect. Of course, you will benefit from doing cardio in the evening, but you will impair the effect of the after burn effect because your metabolic rate drops drastically as soon as you go to sleep. Some researches support this theory, where it has been tested on subjects who burned 1kg of fat faster when exercised in fasted state in the morning, compared to individuals who had few meals throughout the day exercised later.

A study on respiratory gas exchange, caloric expenditure, and carbohydrate/fatty acid metabolism in individuals who exercised after 12 hours of fast has shown 67% of the energy expenditure that came from fat, compared to 50% expenditure achieved when individuals who did the same exercise later in the day or after having food. Also, another study supports the hypothesis that endurance training enhances lipid oxidation in men after a 12 hour overnight fast.

Of course both methods of exercising either in fasted or fed state has their own pros and cons. This highly depends on the individual and their goals. Some other benefits of training on empty stomach can be improved performance and helps avoid stomach upsets. On the other hand there are negatives as well which could be decreased ability to work at higher intensity for longer, lower stamina, and can lead to muscle loss.

As previously mentioned both methods have their benefits and its side effects, this depends all on the individual and its goals. At the end, it is very important to follow your body and find what works and feels best for it. 



Read, F. C. M. F. cardio on an empty stomach.

Aceto, Chris. Everything you need to know about fat loss. Club Creavalle, Inc. (1997)

Bergman, BC, Brooks, GA. Respiratory gas-exchange ratios during graded exercise in fed and fasted trained and untrained men. Journal of Applied Physiology. (1999) 86: 2.

Brehm, B.A., and Gutin, B. Recovery energy expenditure for steady state exercise in runners and non-exercisers. Medicine and Science in Sports and Exercise. (1986) 18: 205,

Gym 101: Progressive Overload

Whether you’re a recreational fitness enthusiast or an elite athlete in order to make the most out of any training programme it is crucial to have a well-structured plan that follows fundamental principles of training. One major component in all training programmes is the principle of progressive overload.

What is the principle of progressive overload?                                                                                        

“Progressive overload is the gradual increase of stress placed on the body during resistance training. In reality, resistance training is only effective for improving health and performance if the human body is continually required to exert a greater magnitude of force to meet higher physiologic demands. Thus, a gradual increase in demand of the resistance training programme is necessary for long-term improvement in muscular fitness and health.” (Kraemer, Ratamess and French, 2002)

This principle isn’t necessarily limited to only resistance training, and can be applied to any type of physical training (running, jumping, lifting, etc.) where the goal is simply to “improve”. There are various ways to implement the principle of progressive overload in your workout regimen and lucky for you below you can find a short list that I prepared for you:

  • Intensity:

You can manipulate the intensity of the exercise by increasing the weight/resistance. Heavier weights or an increased resistance will over time lead to an adaptation by your muscles, connective tissue, bone and nervous system. In other words you will get bigger and stronger!

  • Volume (aka Sets & Reps) :

There are situations where increasing the intensity of the exercise is out of question. Or you may simply want to play around with other aspects of your training. Then increasing the number of repetitions in a given set or increasing the total number of sets for a given exercise is a good option which will eventually lead to improvements in muscular endurance and hypertrophy (increase in muscle size).

  • Tempo:

Tempo is another aspect that could be manipulated to achieve progressive overload in your training. As far as lifting is concerned tempo indicates the time spent in concentric, eccentric as well as isometric parts of the exercise. A quicker concentric contraction will lead to improvements in power while a slower is likely to lead to a longer “time under tension” and eventually to muscular hypertrophy. 

  • Frequency:

This is basically how often you work out in a given time. Let’s say if you work out 3 times a week, then an additional 4th day would lead to an increase in frequency and various adaptations. But this one is a bit tricky as you may not want to increase the frequency forever and end up living in the gym. This can not only hurt your life, but many other aspects of your health as well. So, my advice is to be very mindful with this one and listen to your body. If you constantly start feeling fatigued, don’t see any improvements in the gym for an extended period or struggle with your sleep, these are all your body telling you to slow down a little.

  • Exercise Variety

Last but not least, you can implement different exercises in your routine. This doesn’t necessarily mean that you should change your entire routine every session, but once the improvements plateau in your existing plan then you may want to consider replacing some of the exercises with alternatives.


Kraemer, W.J., Ratamess, N.A. & French, D.N. Resistance training for health and performance. Curr Sports Med Rep 1, 165–171 (2002).

Aydin Parmaksizoglu