A conversation about the visible effects of nutrition, the architecture exercise creates in the body, and the biology of movement from stem cells to wound healing
| For a time, body transformation was reduced to two short sentences: ‘Eat less, move more.’ Then came the opposite extreme: lift heavier, run longer, sweat more… Yet the human body is not a calorie calculator. Muscle, adipose tissue, bone, the vascular system, hormones, immunity, sleep and the nervous system all speak at once. Real change emerges from the balance these systems establish with one another. Which matters more in shaping the body: nutrition or exercise? Is the best exercise really the most exhausting? How does an eating pattern become a lasting way of life rather than a temporary diet? What do studies showing that exercise mobilises bone-marrow stem and progenitor cells into the circulation tell us about healing biology? And how will the future concept of sport balance technology with human biology? |
VOX AESTHETIC: If we compare exercise and nutrition in shaping the body, which should take priority?
Dr Serdar Bora Bayraktaroglu: First, we must distinguish what we mean by ‘shaping the body’. Losing weight, reducing body-fat percentage, increasing muscle mass, decreasing waist circumference, improving posture and looking more athletic are not the same goal.
If the question concerns only lowering the number on the scale, nutrition is the stronger and more direct tool for most people. It is remarkably easy to replace within minutes the energy expended during a workout. Even a small post-exercise snack eaten with the thought, ‘I earned this’, can cancel out the energy cost of the cardio. The body sometimes applies mathematics more ironically than we expect.
In a frequently cited 12-month randomised trial, 439 overweight or obese postmenopausal women were assigned to diet, aerobic exercise, combined diet and exercise, or a control group. Mean weight loss was 8.5% with diet alone, 2.4% with exercise alone and 10.8% in the combined group. One important detail, however, was that the exercise group preserved lean body mass more effectively. These results cannot be transferred directly to every age, sex and form of exercise: the study examined aerobic exercise in a specific population. Even so, its central message is instructive. Nutrition may change total weight more quickly; exercise helps determine the kind of body into which that weight loss translates.
The scale measures kilograms; the mirror sees the relationship between tissues. Of two people at the same weight, one may appear firmer, more balanced and younger, while the other looks softer and less strong. The difference often lies in muscle mass, fat distribution, posture and movement capacity.
My answer is therefore this: nutrition is the first lever for fat loss, while resistance exercise is indispensable to the body’s architecture. Cardiovascular exercise completes the structure by supporting circulation, endurance, insulin sensitivity and heart health.
Losing a substantial amount of fat through exercise alone, without nutritional change, can be difficult. Losing weight through diet alone, without exercise, may not produce the desired body because of muscle loss. The most successful transformation happens where these two fields do not compete, but complement one another.
Put another way: nutrition removes excess material; exercise builds a new architecture with what remains.
| “Nutrition can change total weight; exercise determines what kind of body that weight loss creates.” |
VOX AESTHETIC: Exercise no longer means unlimited weights or endless cardio. So what is the ‘best exercise’?
Dr Serdar Bora Bayraktaroglu: The best exercise is not the name of one particular movement. Squats, running, Pilates, swimming and the much-discussed high-intensity interval training cannot each be ‘the best’ in isolation.
The best exercise is the right dose, tailored to the individual’s goals, age, musculoskeletal structure, health, history and capacity for recovery.
The word ‘dose’ matters. Like a medicine, exercise produces adaptation when delivered in the right amount. Too little may be ineffective; too much can increase fatigue, reduce performance, disrupt sleep and raise injury risk. The goal is not to exhaust the body at every session, but to provide a stimulus strong enough for it to develop.
A sound programme considers four fundamental systems together. Resistance exercise is the body’s load-bearing architecture, supporting strength, muscle mass, mechanical stimulation of bone and everyday function. Cardiovascular exercise is the engine, developing the capacity of the heart, lungs and circulation. Mobility and balance work form the steering system, allowing us to use our strength safely and with control. Sleep and rest are the maintenance workshop, because the body grows stronger through adaptation after training, not during the workout itself.
For adults, the World Health Organization recommends a total of 150-300 minutes of moderate-intensity aerobic activity per week, or the vigorous-intensity equivalent, plus muscle-strengthening activity involving the major muscle groups on at least two days per week. These figures are not an individual programme, but a general framework for protecting health.
The American College of Sports Medicine’s updated 2026 review of resistance exercise highlights a simple point: for most adults, the greatest benefit appears when they move from no resistance exercise to a regular, progressive programme. Consistency comes before complexity. Free weights, machines, resistance bands or body weight can all be used; the key is to train the major muscle groups regularly and progress the load over time according to individual capacity.
The belief ‘I must lift the heaviest weight’ is therefore as incomplete as ‘The longer I run, the better’. Excessive cardio, especially when combined with inadequate nutrition and rest, may increase muscle loss and chronic fatigue. Uncontrolled weight training can overlook the fact that joints and tendons adapt more slowly than muscles.
High-intensity interval training can be time-efficient and effective for the right person. HIIT, however, is a seasoning, not the whole meal. Training at maximum intensity every day is not a sustainable sporting life.
I define the ‘best exercise’ through five qualities: it should be individualised, progress measurably, include different physical systems, remain within the person’s capacity to recover and, most importantly, be sustainable over time.
A simpler programme maintained for years is more valuable than a theoretically perfect one abandoned after three weeks. Biology responds more to repeated habits than heroic displays.
| “The best exercise is not the hardest programme the body can withstand, but the right dose from which it can recover.” |
VOX AESTHETIC: The main problem with nutrition is that most programmes cannot be sustained. How can nutrition become a way of life for someone who exercises?
Dr Serdar Bora Bayraktaroglu: If an eating programme works only when we are not on holiday, work is quiet, we can prepare every meal at home and we have no social life, it is not a lifestyle. It is a temporary project.
People often ask which diet produces faster results: low-carbohydrate, low-fat, ketogenic or intermittent fasting. The more decisive long-term question, however, is whether the approach fits the person’s life, culture, working hours, training and social relationships.
In the DIETFITS trial, 609 overweight or obese adults were assigned to healthy low-fat or healthy low-carbohydrate diets. After 12 months, there was no significant difference in weight loss between the two approaches. Importantly, both groups emphasised food quality, vegetables, whole foods and fewer refined products. This suggests that no single macronutrient ratio is superior for everyone, and that food quality and sustainability often matter more than the diet’s label.
For an active person, nutrition should not mean merely reducing calories. It has three tasks: to provide energy for training, help tissues recover afterwards and protect long-term health.
A strong foundation therefore includes a recognisable protein source at each main meal, regular consumption of vegetables, fruit and fibre-rich foods, carbohydrate intake adjusted to training load, adequate healthy fats and sufficient fluid.
Declaring carbohydrate an absolute enemy is inappropriate, particularly for active people. Carbohydrate is an important fuel for high-intensity training. The question is not whether it exists in the diet, but its type and quantity in relation to energy expenditure. A rest day and a long, demanding training day may not require the same energy intake. Nutrition should be a living system that adapts to activity levels, not a fixed menu.
Likewise, protein is not only for professional bodybuilders. It should be a natural part of daily nutrition to preserve muscle, support training adaptation and limit age-related muscle loss. Building a diet around protein powder, however, is like buying the bricks and forgetting the rest of the building. Supplements can help when needed; the foundation should be real food.
Another danger is mistaking chronically low energy intake for discipline. In people training intensively, prolonged and marked energy deficiency can adversely affect hormones, bone health, immunity, psychological wellbeing, recovery and performance. The International Olympic Committee describes this condition, seen in both female and male athletes, as Relative Energy Deficiency in Sport.
The aim is not to eat as little as possible. It is to eat with enough control to support the desired body composition and enough adequacy to protect health and performance.
Foods should not be placed into moral categories such as ‘good’, ‘bad’, ‘forbidden’ and ‘cheat’. One meal does not make a person healthy or unhealthy. Outcomes are created by the overall pattern repeated over weeks and months.
A lifestyle approach to nutrition can adapt to travel, restaurants, family meals and demanding workdays. It aims not for perfection, but to maintain direction. Over the long term, our bodies are shaped less by what we eat on special occasions than by the choices we repeat on ordinary days.
| “The aim is not to eat as little as possible, but to eat appropriately enough to protect health and performance.” |
HOW DOES EXERCISE AFFECT HEALING BIOLOGY?
This field is fascinating, particularly from my perspective as a plastic surgeon and genetic engineer working in stem-cell biology. Yet scientific excitement must remain balanced by restraint.
Bone marrow is not merely a passive blood-cell factory. It is a dynamic biological environment containing stem and progenitor cells, immune cells and various supportive cells. Increased sympathetic nervous-system activity, catecholamines, circulation, shear stress at the vessel wall and certain cellular signals during exercise may alter traffic between the bone marrow and circulation.
Some experimental human studies have shown that acute aerobic exercise above a certain intensity temporarily increases circulating CD34-positive haematopoietic stem and progenitor cells. In a study by Agha and colleagues involving small groups of healthy adults, the total circulating CD34-positive cell count approximately doubled relative to rest after 30 minutes of high-intensity exercise. A longer bout of moderate-intensity exercise did not produce a similar response under the same protocol, and the findings suggested a role for beta-2 adrenergic signalling in mobilisation. Other human studies have also reported that this response may be related to exercise intensity.
A small but important scientific qualification is necessary: CD34-positive cells are not a uniform, pure ‘army of stem cells’. The marker identifies a heterogeneous population of haematopoietic stem and progenitor cells at different stages of development. An increase in the blood does not automatically mean that these cells travel to a particular wound and become tissue.
The reparative effects of exercise probably arise not from a single cell type, but from multiple mechanisms working together. Regular movement supports endothelial function, improves tissue perfusion, assists glucose control and may reduce chronic low-grade inflammation. Myokines released from skeletal muscle generate systemic signals affecting immunity and metabolism. Endothelial progenitor cells entering the circulation during exercise have also been associated with vascular repair and new-vessel formation. Experimental human and animal studies have shown that physical training may increase endothelial progenitor cells and angiogenesis.
Clinical evidence relating to wound healing is more limited but intriguing. In a small, randomised pilot study of 28 healthy older adults, experimental skin wounds healed in an average of 29.2 days among participants completing a three-month moderate-intensity exercise programme, compared with 38.9 days in the non-exercising group. Because the study was small, the finding cannot be generalised to every patient or surgical procedure. It is nevertheless important in suggesting that regular exercise may improve the biological environment in which healing occurs.
It would therefore be incorrect to conclude, ‘Exercise mobilises stem cells, so sport heals every wound.’ Exercise-induced cellular mobilisation is transient; how many cells reach the target tissue, what they do there and to what extent this translates into clinical outcomes remain under investigation.
We can make a safer statement: regular exercise may strengthen the foundation on which the body’s healing capacity operates. By supporting circulation, metabolic balance, muscle reserve, vascular health and immune response, it may prepare the organism more effectively for repair.
From a surgical perspective, exercise’s most valuable role is often not strenuous training immediately after an operation, but building greater physiological reserve beforehand. Following surgery, the timing of a return to walking and exercise should be determined by the surgeon according to the procedure, wound location, and risks of bleeding and swelling. During recovery, ‘more’ is not always ‘better’.
Exercise does not suture the wound, but it may strengthen the organism in which the wound heals.
| “Exercise does not suture the wound, but it may strengthen the organism in which the wound heals.” |
VOX AESTHETIC: What will the sport of the future look like?
Dr Serdar Bora Bayraktaroglu: It is difficult to define the sport of the future through one device, gym or training trend. The real transformation will be a move away from ‘the same programme for everyone’ towards personalised, feedback-driven systems that change in response to the body.
In the past, a programme was written on paper and followed largely unchanged for weeks. In the future, age, goals, training history, chronic disease, sleep, resting heart rate, perceived recovery, pain, movement quality and daily-life demands will be assessed together. The programme will not merely be personalised at the outset; it will be readjusted according to the individual’s response. Exercise will resemble a living prescription more than a fixed one.
Wearable technology will be the most visible aspect of this change. In the American College of Sports Medicine’s 2026 trends survey, wearables ranked first, programmes for older adults second, mobile exercise applications fourth, and balance, flow and core training fifth. This shows that the future of exercise will develop not only around records, speed and muscle size, but around active ageing, movement quality, weight management and accessibility.
Smartwatches, rings and sensors can monitor heart rate, steps, speed, sleep and training load. Artificial intelligence may identify patterns and recommend reducing training volume, increasing intensity or prioritising recovery. There is an important boundary, however: data should not make decisions in place of the body. The World Health Organization’s recent work on measuring physical activity through wearables also emphasises the need for common metrics and device accuracy, as well as gaps in protocols and knowledge that remain unresolved.
A device may say that a person has ‘recovered’, while they feel joint pain, disturbed sleep or marked reluctance to train. The reverse is also possible: one poor night’s sleep is not enough to declare the entire week a failure. The athlete of the future will therefore not be the person with the most data, but the one able to interpret data alongside body awareness and expert assessment.
The second major change will concern the goal itself. Future exercise will aim not only to create a slimmer appearance or lift more weight, but to extend ‘healthspan’. Muscular power will matter alongside strength, balance alongside aerobic capacity, range of motion alongside bone health, and the ability to continue without injury alongside performance. Aesthetic outcomes will remain, but will be repositioned as a natural consequence of a functionally and metabolically strong body.
The third change will be that exercise is no longer confined to one hour of the day. Gym training will remain important, but hybrid models combining short movement breaks, walking meetings, stairs, active transport, the home, outdoors and digital platforms will become part of daily life. The aim will not be to replace structured training with a step count, but to integrate planned exercise with general daily movement.
The fourth change is a more permeable boundary between exercise and medicine. Treating physical activity as a vital sign during clinical consultations, condition-specific exercise prescriptions, preoperative prehabilitation, graded postoperative return and collaboration between physicians and exercise professionals in chronic disease will become increasingly important. The American College of Sports Medicine’s ‘Exercise is Medicine’ initiative aims to make physical-activity assessment and evidence-based exercise referral a standard part of clinical care.
The social dimension will also grow. Gamification, virtual groups, remote coaching, shared goals and a sense of community may make it easier not only to begin exercising, but to continue. The randomised STEP UP trial of 602 adults monitored with wearables found that gamified interventions incorporating support, collaboration and competition could increase physical activity, although design was decisive to the outcome. Technology gains value when it becomes not a screen that isolates people, but a bridge making movement social and meaningful.
Virtual and augmented reality may play a larger role in rehabilitation, balance training and the exercise experience. AI-supported systems may provide real-time feedback, adapting movement speed, repetitions or difficulty. Their effectiveness, however, depends on collaboration between exercise science, clinical assessment, behavioural science and technological expertise.
In my view, the greatest risk is turning movement into another form of performance anxiety. People once surrendered to the mirror, then the scale, and may now surrender to sleep and recovery scores. Technology is useful when it increases body awareness; when it weakens a person’s ability to listen to their own body, it becomes merely a more polished instrument of pressure.
The future model will therefore follow a cycle of ‘measure, interpret, apply, recover and readjust’. The most successful athlete will not be the person who works the most, but the one who can adapt their programme through different stages of life, progress without injury and preserve strength and freedom of movement over many years.
The sport of the future will not silence the body; it will teach us to listen to it more closely.
| “Data can guide training, but should not decide in place of the body.” |
VOX AESTHETIC: What single message should readers retain from this conversation?
Dr Serdar Bora Bayraktaroglu: The body changes not by being starved or constantly exhausted, but by being properly nourished, appropriately loaded and adequately recovered.
Nutrition determines the direction of fat loss. Resistance exercise builds the body’s architecture. Cardiovascular exercise develops its circulatory and endurance systems. Sleep and rest convert all these stimuli into genuine biological adaptation.
Exercise is not merely calorie expenditure. It is a biological message sent to muscle, bone, blood vessels, the immune system and even the bone marrow.
Sport is therefore not a punishment, but a long-term partnership with the body.
