The global obesity epidemic, affecting over one billion people worldwide, is largely driven by eating behaviors. Appetite, influenced by both intrinsic and environmental factors, plays a crucial role in weight management. A recent study how exercise affects appetite perception in obese males, shedding light on the physiological mechanisms behind hunger suppression post-exercise.

While exercise is well-known for its benefits in weight management, its direct impact on appetite control has remained a subject of debate. Appetite is regulated by a complex network of gastrointestinal and neurohormonal signals, including hormones like ghrelin, leptin, interleukin 6 (IL-6), and neuropeptide Y (NPY). These hormones influence hunger levels, satiety, and energy balance.

The study published in Physiological Reports examines investigated how moderate continuous aerobic exercise (MICE) alters these hormone levels in obese men, ultimately affecting their hunger perception. The findings reveal that certain myokines and cytokines shift dynamically post-exercise, potentially reducing appetite and offering a promising strategy for weight management.

Hormonal Responses to Exercise

The study found that after exercise, there was a significant increase in IL-6 and irisin levels in the exercise group compared to those who remained sedentary. These elevated concentrations persisted for an hour after working out. IL-6 has been associated with regulating metabolism and enhancing fat oxidation, while irisin plays a role in converting white fat into more metabolically active brown fat.

Conversely, the study reported a decrease in neuropeptide Y (NPY) levels, a key neurotransmitter responsible for stimulating appetite. The decline in NPY levels post-exercise suggests a temporary suppression of hunger, supporting the idea that exercise can curb cravings. However, the study did not observe significant changes in IL-7 or leptin levels, two other hormones involved in appetite regulation.

Why Some People Struggle to Lose Weight

Ghrelin, often called the “hunger hormone,” stimulates appetite by increasing activity in specific areas of the brain. Individuals with higher ghrelin levels generally find it harder to lose weight because their bodies signal hunger more frequently.

Research suggests that dieting can lead to an increase in ghrelin levels, making weight loss challenging. Certain medical conditions, such as Hashimoto’s thyroiditis, Prader-Willi syndrome, anorexia nervosa, and bulimia nervosa, are also linked to elevated ghrelin levels, complicating appetite regulation further.

Challenges in Implementing Exercise for Appetite Control

While exercise has clear benefits, the findings should be interpreted with caution. He pointed out that the study had a small sample size, making it difficult to draw definitive conclusions.

Moreover, he highlighted the challenges faced by obese individuals in maintaining an intensive exercise routine. While exercise-induced appetite suppression is promising, consistently engaging in high-intensity workouts may be unrealistic for those who struggle with mobility or fitness levels. More extensive studies are needed to determine the optimal exercise duration and intensity for effective appetite suppression.

Tips to Naturally And Safely Suppressing Appetite

Besides exercise, there are several strategies individuals can use to naturally suppress their appetite and improve satiety:

Increase Protein Intake: Protein-rich foods, such as lean meats, legumes, and dairy, promote feelings of fullness and reduce hunger.

Stay Hydrated: Drinking water before meals can help control portion sizes and prevent overeating.

Opt for Fiber-Rich Foods: Whole grains, vegetables, and fruits high in fiber take longer to digest, keeping you full for longer.

Reduce Simple Carbohydrates and Sugars: Simple carbs and sugars cause rapid spikes and crashes in blood sugar levels, leading to increased hunger.

Prioritize Sleep: Poor sleep disrupts hunger-regulating hormones, making it harder to control cravings.

Manage Stress: Chronic stress increases cortisol levels, which can lead to overeating and weight gain.

The study’s findings indicate that moderate exercise can temporarily suppress appetite by altering key hormones. While more research is needed to refine the details—such as optimal workout duration and intensity—this insight adds to the growing body of evidence supporting exercise as a tool for appetite regulation and weight management.

For individuals looking to curb cravings and maintain a healthy weight, incorporating a well-balanced diet alongside regular exercise remains the most sustainable approach. Future studies focusing on larger populations and long-term effects could provide deeper insights into how exercise can be optimized for appetite control, making it an effective strategy in combating obesity.

Exercise alone is not a magic solution for weight loss, but its impact on appetite hormones presents a promising avenue for managing hunger and energy balance. As research continues to evolve, it becomes increasingly clear that integrating physical activity with mindful eating habits can play a vital role in achieving and maintaining a healthy lifestyle.

"Losing weight isn't about obsessing over diets or rushing to shed pounds."

It is about understanding the reasons behind why a person weighs as much as they do and adopting healthy habits to create long-term success. From an endocrinologist's viewpoint, managing weight involves a thorough approach. Factors such as hormonal imbalances, insulin resistance, thyroid conditions, polycystic ovary syndrome (PCOS), some medications, genetics, and lifestyle choices can all affect body weight. As a result, a single diet or exercise routine may not be equally effective for everyone.

Why Weight Management Needs A Personalised Approach

Also read: Delhi Air Pollution: Should You Move Your Morning Walk And Jog Indoors As AQI Nears 400?

Eating a balanced diet high in nutrients is a key principle to weight control. It's advised not to cut out all food groups or eat extreme low amounts of calories, but ensure that your diet includes moderate portions, lots of protein, fibre-dense, foods, veggies, fruits, and good fats. Participating in a regular exercise programme with cardio exercises and resistance training can boost your metabolic health.

Sleep and behaviour are equally vital. Poor sleep can impact hunger hormones and it can cause cravings, then add stress and emotional eating maintenance can be tricky. Keeping to a sleep routine, managing stress and setting realistic targets will aid in developing a lasting habit.

When Are Weight-Loss Medicines Or Surgery Considered?

Assessment of diet there are certain circumstances, when medical assessment would be the next step, such as significant unexplained weight gain, the failure to lose weight despite an effort, and if there is a presence of other manifestations/diseases like diabetes, high blood pressure, hormonal problems etc. A personalised evaluation is a review of medical history, medication, and relevant investigations and metabolic risk factors.

Your healthcare professional may recommend prescription weight-management medication to use beyond nutrition and lifestyle management, where your weight management plan is based on your BMI, related health conditions and clinical management. Your healthcare professional will need to monitor treatment with medication. You may also be considered for bariatric surgery where clinically indicated.

It's not about hitting the scales at a lesser weight; the aim should be to achieve good metabolic health, physical fitness and quality of life. The fact is that weight loss is a slow journey, and even small, sustainable weight loss can bring significant health gains. A custom program, ongoing assessment and adequate support will beat fad diets every time."

By Dr Hetashvi Gondaliya, Diabetes & Endocrinology, CK BIRLA HOSPITALS Jaipur

A 24-year-old marathon runner, Rachel Apa, collapsed and died two miles from the finish line at the New York City Marathon. In Hyderabad, 36-year-old IBM software engineer Kommineni Gopi died after suffering a heart attack shortly after completing a marathon.

Apa's death was attributed to rhabdomyolysis, a condition involving severe muscle breakdown, while Gopi died following a heart attack.

Also Read: Delhi AQI Crosses 2,000 Mark After Diwali: What Happens To Your Body Within Hours Of Exposure?

According to The New York Times, Apa was a former Division I field hockey player at Bucknell University who had trained for months. Gopi was an experienced amateur runner who had undertaken intensive training and multiple endurance runs.

Although such deaths are rare, the incidents highlight the physical demands of endurance running.

How Common Are Deaths During Marathons?

A study published in JAMA, involving 29.3 million US marathon and half-marathon finishers between 2010 and 2023, found:

• Cardiac arrest: 0.54 per 100,000 participants (1 in 185,000).
• Cardiac death: 0.20 per 100,000 (1 in 500,000).

Dr Sudhir Kumar, neurologist at Apollo Hospitals, Hyderabad, said survival has improved with better on-site CPR and defibrillation.

Also read: Water Or Electrolytes? Biggest Hydration Mistakes First-Time HYROX Athletes Make

Who Is At Greater Risk?

According to Dr Sudhir, risk factors include:

• Male sex: Cardiac arrest rates are approximately six times higher in men.
• Older age: Risk rises after 40–50 years.
• Underlying heart conditions: Including coronary artery disease, cardiomyopathy and myocarditis.
• Race distance: Full marathons carry higher cardiac arrest risk than half-marathons.
• Environmental stress: Heat, humidity, dehydration and illness.

Can Extreme Running Affect Heart Health?

Regular running is associated with lower cardiovascular and all-cause mortality and better blood pressure and glucose control.

However, prolonged extreme endurance training may increase the risk of atrial fibrillation, coronary artery calcification in some athletes and myocardial fibrosis in a small subset. These risks remain low for most runners.

What Causes Cardiac Arrest During A Marathon?

Read More: Lancet Study: 1 In 4 Adolescents Worldwide Report No Active Days Every Week: What Are The Health Risks?

Causes vary by age. Younger runners (below 35–40 years):

• Hypertrophic cardiomyopathy
• Arrhythmogenic cardiomyopathy
• Congenital coronary anomalies
• Myocarditis
• Inherited arrhythmias

Middle-aged and older runners:

Coronary artery disease is a major cause and can trigger heart attacks or dangerous heart rhythms.

Other causes include heat stroke, severe hyponatremia, aortic dissection, pulmonary embolism and complicated rhabdomyolysis.

What Is Rhabdomyolysis And Why Is It Dangerous?

Rhabdomyolysis occurs when damaged muscles release myoglobin and potassium into the bloodstream. Excess potassium can trigger dangerous heart rhythms, while myoglobin can damage the kidneys.

Warning signs include severe muscle pain, weakness and dark urine.

“A marathon is not ‘normal’ exercise. It is EXTREME exercise. While most people don’t develop a problem, deaths occur rarely too,” said Dr Rajeev Jayadevan, former president of IMA Cochin.

“Rhabdomyolysis (muscle breakdown) releases potassium into the bloodstream that causes cardiac arrest. Later events include BP crash and kidney shutdown,” he added on X.

Cardiac arrests often occur in the final quarter of a race, near the finish line or shortly after completion.

Why Is Marathon Training Important?

Attempting a marathon without adequate preparation can be dangerous.

“If you are not a trained runner, don't run. Running without understanding the science of it, running without being fit, running without having a baseline health check, running without proper stamina and endurance are all recipes to disaster,” warned Dr Deepak Krishnamurthy, director and lead cardiologist at KIMS Hospital, on X.

People over 40, those with diabetes or hypertension, smokers and individuals with a family history of premature heart disease should consider cardiovascular evaluation before intensive training.

How Can Runners Reduce The Risks?

During training:

• Increase mileage gradually.
• Avoid running during illness.
• Stay hydrated and include recovery days.
• Avoid excessive NSAID use.

• Acclimatise to the weather.
• Start at a manageable pace.
• Hydrate according to thirst.
• Stop for chest pain, fainting, unusual breathlessness or palpitations.

What To Do If A Runner Collapses

• Call emergency services.
• Start CPR if the runner is unresponsive and not breathing normally.
• Use an automated external defibrillator (AED) as soon as possible.

Early CPR and defibrillation can improve survival.

Marathons offer health benefits, but runners need adequate preparation and should recognise warning signs rather than push through them.

With Delhi's air quality nearing 400, doctors have advised people to reconsider their morning workout routines. Outdoor activities such as walking, jogging and cycling can increase exposure to harmful pollutants, particularly when air quality levels are poor.

While regular exercise is important for good health, exercising outdoors when pollution levels are high can affect respiratory and cardiovascular health.

Experts told HealthandMe that adjusting workout timings and choosing indoor alternatives can help reduce exposure.

Delhi's air quality deteriorated to the very poor category on Friday morning, with an Air Quality Index (AQI) reading of 391, just days before Diwali.

Forecasts indicate that the AQI could exceed 400 and enter the severe category between Friday and Sunday, with no immediate relief expected. Around 30 of the 59 monitoring stations across the national capital recorded severe pollution levels on Friday morning, with Rohini reporting an AQI of 475.

Should You Change Your Morning Workout Routine?

Dr Arunesh Kumar, Director and HOD, Pulmonology, Paras Health, Gurugram, told HealthandMe that when AQI levels are high, outdoor activities such as morning walks, jogging and cycling increase exposure to pollutants, particularly because breathing becomes faster during exercise.

Experts recommend moving workouts indoors when pollution levels are high. Yoga, stretching, weight training and low-intensity exercises can help you maintain your fitness routine.

"It's important to check the daily AQI before you go out and to consider moving your exercise indoors when the air quality is poor. You can maintain your exercise regime indoors with yoga, stretching, light strength training and the like. A well-ventilated indoor space is preferable and of course you should avoid doing your exercise near major traffic routes," Dr Arunesh said.

Also read: With Delhi AQI Nearing 400, Pollution & Flu Loom Ahead Of Diwali: What Happens When Both Hit Your Lungs?

What Indoor Exercises Can You Do When AQI Is High?

If air pollution levels are high, you can maintain your fitness routine by moving your workouts indoors. Some alternatives include:

• Yoga: Practise yoga indoors to stay active.
• Stretching: Include gentle stretching exercises in your daily routine.
• Weight training: Opt for indoor strength-training exercises.
• Low-intensity exercises: Choose light workouts that can be done indoors.

How Does PM2.5 Affect Your Health?

"Your breathing rate increases whilst working out, meaning that the pollutants you're breathing can get further into your lungs. This can lead to issues with your breathing and heart over time. Checking your AQI before going on a run/walk/cycle can help create a healthy lifestyle," Dr Rajesh Kumar Gupta, Director, Respiratory Medicine and Interventional Pulmonology, Yashoda Medicity, told HealthandMe.

People with asthma or heart conditions, children and older adults should be particularly careful about exposure on days with high pollution.

Read More: Air Pollution In Delhi: Experts Warn Of Red Eyes, Itching, Watering In Children

How Can You Maintain A Healthy Fitness Routine?

Poor air quality does not mean you need to stop exercising altogether. Experts recommend adapting your routine according to pollution levels.

• Check the AQI: Monitor daily air quality levels before planning outdoor activities.
• Move workouts indoors: Choose yoga, stretching, weight training or other indoor exercises when pollution levels are high.
• Avoid traffic-heavy areas: If you exercise outdoors, avoid major roads and congested areas.
• Stay hydrated: Drink enough water throughout the day.
• Eat a balanced diet: Include fruits, vegetables and whole grains in your meals.
• Prioritise sleep: Get sufficient rest.
• Avoid smoking: Smoking can further affect your health.

Lifestyle choices such as eating a balanced diet, staying hydrated, sleeping well and avoiding smoking support overall well-being, although they cannot prevent the harmful effects of air pollution.

The aim is not to stop exercising but to modify physical activity according to air quality conditions, said the experts. People with respiratory conditions, heart disease, older adults and children should be particularly mindful of their exposure on high-pollution days.