Hypokinetic Disorders, Yoga, and Substance Abuse

Hypokinetic disorders

Hypo = too little, kinetic = movement. Diseases caused by insufficient physical activity.

They are now the leading cause of death in India, having overtaken infectious disease — and they are largely preventable, which is the point of naming them.

Obesity. Energy intake persistently exceeding expenditure. BMI is the usual screen:

WHO categories are under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese — but the cut-offs for Asian Indians are lower, with overweight from 23 and obesity from 25, because cardiometabolic risk appears at a lower BMI in South Asians.

BMI has real limitations. It ignores body composition, so a muscular person is misclassified, and it ignores fat distribution. Waist circumference matters more — above 90 cm for men and 80 cm for women indicates abdominal obesity, which carries the metabolic risk. South Asians characteristically carry fat abdominally at a normal BMI, sometimes called the thin-fat phenotype, which is why waist circumference should be measured rather than BMI alone.

Cardiovascular disease. Coronary artery disease — atherosclerotic plaque narrowing the coronary arteries, causing angina and myocardial infarction. Hypertension — sustained blood pressure at or above 140/90, largely symptomless, which is why it is called the silent killer and why it must be measured rather than felt.

Type 2 diabetes. Insulin resistance with relative insulin deficiency. India has among the largest diabetic populations in the world, and onset is typically a decade earlier than in Western populations. Physical activity improves insulin sensitivity directly and independently of weight loss.

Osteoporosis. Loss of bone density, with fracture risk. Peak bone mass is reached in the late twenties, so weight-bearing exercise and adequate calcium and vitamin D now determine risk decades later.

Musculoskeletal disorders, several of them directly relevant to a student who sits and studies:

• Osteoarthritis — cartilage degeneration in weight-bearing joints.
• Low back pain — extremely common; associated with prolonged sitting, weak core muscles and poor posture.
• Kyphosis — excessive outward curvature of the upper spine, the hunched posture of long hours over a laptop.
• Lordosis — excessive inward curvature of the lower back.
• Flat foot, knock knee — structural conditions of the lower limb.

Prevention is the same short list in every case: regular activity, strength work, a balanced diet, healthy weight, no tobacco, limited alcohol, adequate sleep, and breaking up prolonged sitting.

On sitting specifically: prolonged uninterrupted sitting carries risk that is not entirely offset by a single daily exercise session. Standing and moving for a few minutes every half hour is a separate intervention from exercising, and both are needed. For an engineering student this is the most directly applicable sentence in the course.

Yoga

Meaning. From Sanskrit yuj, to join or unite — the union of body, mind and breath.

Aims and objectives: physical health and flexibility; mental calm and concentration; emotional balance; and, in its traditional context, spiritual development. In the present course the emphasis is on health and stress management.

Classification of asanas by position, as the syllabus specifies:

• Sitting — Padmasana, Vajrasana, Sukhasana, Paschimottanasana.
• Standing — Tadasana, Trikonasana, Vrikshasana, Virabhadrasana.
• Lying — supine: Shavasana, Setu Bandhasana; prone: Bhujangasana, Dhanurasana.

Importance: improves flexibility and joint mobility; strengthens without equipment; improves posture, which addresses the kyphosis and back pain above; and reduces stress measurably.

Pranayama — regulation of breath. Prana = life force, ayama = extension. Types include Anulom Vilom (alternate nostril), Bhramari (humming), Kapalbhati (forceful exhalation), Bhastrika (bellows) and Ujjayi.

Why breathing techniques affect stress, stated mechanistically rather than mystically: slow breathing, particularly with a prolonged exhalation, increases parasympathetic (vagal) activity, which lowers heart rate and blood pressure. This is a measurable physiological effect, and it is why slow breathing is used in clinical stress management as well as in yoga.

Practical cautions. Learn from a qualified teacher; do not force a posture; practise on an empty stomach; avoid inversions with high blood pressure, and Kapalbhati in pregnancy, hypertension or hernia.

Substance abuse and addiction

This section is factual and preventive. If you or someone you know is struggling with substance use, help is available — through a college counsellor, a doctor, or a de-addiction service.

Substance abuse — use in a way that harms health or function. Addiction (substance use disorder) — compulsive use despite harm, with tolerance, withdrawal and loss of control.

How dependence develops. Psychoactive substances act on the brain's dopamine reward pathway. Repeated use causes neuroadaptation: the system down-regulates, so more is needed for the same effect (tolerance), and its absence produces distress (withdrawal). At that point use continues to avoid feeling bad rather than to feel good, which is why "just stopping" is far harder than it looks from outside.

The classes named in the syllabus, and their principal harms:

• Alcohol — depressant. Impairs judgement and coordination; chronic use causes liver disease, cardiomyopathy, several cancers and dependence.
• Opioids — heroin, and misused prescription analgesics. Strongly addictive; respiratory depression is the mechanism of fatal overdose.
• Cannabis — impairs memory, attention and coordination; regular use in adolescence is associated with poorer educational outcomes and, in vulnerable individuals, with psychosis.
• Sedatives — benzodiazepines and similar. Dependence develops readily; combining them with alcohol or opioids is a common cause of fatal respiratory depression.
• Cocaine and other stimulants — including amphetamines. Cardiac arrhythmia, stroke, and severe dependence.
• Caffeine — a stimulant, and mild dependence is real, though harms are modest at ordinary intakes. Worth noting because students often do not count it.
• Hallucinogens — perceptual distortion, unpredictable reactions.
• Tobacco — nicotine is among the most addictive substances known. The leading preventable cause of death worldwide: lung and other cancers, COPD, cardiovascular disease. Smokeless forms are widely used in India and cause oral cancer.
• Volatile solvents — glue, paint thinner, correction fluid. Cheap and accessible, which is why they are used by the young; cause irreversible brain, liver and kidney damage, and sudden sniffing death from cardiac arrhythmia even on first use.

Why students are at particular risk: the prefrontal cortex, which governs impulse control and consequence-weighing, continues developing into the mid-twenties. Combined with peer influence, new independence and academic stress, that makes this the period of highest initiation risk — and the earlier use begins, the more likely dependence becomes.

Prevention. Accurate information; refusal skills; managing stress by means that work; social connection; and, if use has already begun, seeking help early, when it is far more treatable.