Dear I am a 36-year-old working professional.I am very skinny.Can you suggest me how can my weight gaining?

An ectomorph tends to be thin and struggles to gain weight.

You may have this body type wherein you may be typically skinny and have a light build, with small joints and lean muscle.

You may have fast metabolism and so may need a huge amount of calories to put on weight.

Workouts should be short and intense, focusing on big muscle groups.

Less aerobic activities should be your goal.

Supplements may be necessary to support the workout and muscle build up.

Since you are a vegetarian, aim at acquiring good protein combinations from plant foods and good quality protein absorption.

Include milk and milk products as well.