Authors and Institutions

• Dr. Shekoofeh Mottaghi and colleagues
• Ardakan University, Yazd, Iran
• Shahrekord University, Iran
• Shahrekord University of Medical Sciences, Iran

When and Where Was the Study Done?

The study was conducted in Shahrekord, Iran, during the 2023–2024 academic year. It was published in Annals of Medicine & Surgery in 2026.

Why Was This Study Conducted?

Researchers were concerned that many adolescents are becoming less physically active, leading to:

• Reduced fitness
• Higher blood pressure
• Increased risk of obesity
• Poor cardiovascular health

Most previous Laughter Yoga studies focused on psychological benefits such as stress, anxiety, and depression. The researchers wanted to know whether Laughter Yoga could also improve:

• Heart function
• Lung function
• Metabolic health

in healthy teenage girls.

Participants

• 64 healthy girls
• Age: 13–15 years
• Randomly divided into:
  • Laughter Yoga Group (32)
  • Control Group (32)

All participants:

• Had no cardiovascular disease
• Had no metabolic disorders
• Were not exercising regularly before the study

Laughter Yoga Protocol

The intervention lasted 8 weeks.

Frequency

• 16 sessions total
• One session every other day

Duration

• 40 minutes per session

Session Structure

5 Minutes

• Deep breathing exercises

10 Minutes

• Warm-up exercises and rhythmic clapping

10 Minutes

• Childlike playful activities

15 Minutes

• Laughter exercises

Sessions ended with:

• Relaxation
• Smiling
• Mindfulness
• Positive affirmations

 

What Did the Researchers Measure?

Metabolic Health

• Fasting Blood Sugar (FBS)
• Triglycerides
• Total Cholesterol
• HDL ("good cholesterol")
• LDL ("bad cholesterol")

Cardiovascular Function

• Heart Rate
• Blood Pressure
• Stroke Volume
• Cardiac Output Index

Lung Function

• FEV1
• FEV1/FVC Ratio
• FEF25–75%
• Forced Expiratory Time (FET)

Major Findings

1. Metabolic Health Improved

After 8 weeks of Laughter Yoga:

Fasting Blood Sugar

91 → 85 mg/dL

Total Cholesterol

140.18 → 132.62 mg/dL

HDL (Good Cholesterol)

43.18 → 46.88 mg/dL

Triglycerides

Significant improvement was observed.

What This Means

Laughter Yoga may:

• Improve blood sugar control
• Improve cholesterol levels
• Support long-term heart health

2. Heart Health Improved

Heart Rate

90.25 → 80.25 beats/min

Systolic Blood Pressure

113.12 → 106.87 mmHg

Diastolic Blood Pressure

70.62 → 68.12 mmHg

Stroke Volume

41.90 → 45.21 ml

Cardiac Index

3.25 → 3.63 L/min/m²

What This Means

The heart became:

• More efficient
• Less stressed
• Better able to pump blood

Researchers suggest that Laughter Yoga activates the parasympathetic nervous system ("rest and relax" system), reducing stress on the cardiovascular system.

3. Lung Function Improved

FEV1

3.07 → 3.35 L

FEV1/FVC Ratio

79.38 → 82.51%

FEF25–75%

70.81 → 80.38

Forced Expiratory Time

79.31 → 55.50 sec

What This Means

Participants showed:

• Better airflow through the lungs
• Stronger respiratory muscles
• More efficient breathing
• Better oxygen exchange

The researchers believe the repeated deep breathing and hearty laughter acted like a gentle respiratory workout.

This study shows that just 8 weeks of regular Laughter Yoga significantly improved:

✅ Blood sugar levels
✅ Cholesterol profile
✅ Blood pressure
✅ Heart efficiency
✅ Lung function
✅ Overall cardiorespiratory fitness

The researchers concluded that Laughter Yoga is a safe, inexpensive, enjoyable, and non-drug method for improving the physical health of adolescents