Weight Loss: Exercise when to start?

Have you ever watched Biggest Loser, Extreme Makeover (weight edition) and other programs related to weight loss? They like to show very huge people performing high impact exercise, sweating, crying, breathing heavily, face is red,,,
If you are overweight do not repeat it at home. Extreme like that should be happening under doctor’s supervision, and even then it cannot be good for your health. When I was very heavy it was very difficult for me to even go upstairs. I could not even imagine doing high impact back then.
Recently we visited New York City. Have you ever noticed that New Yorkers are slimmer? I had same impression being in Paris, Rome, and Moscow. People who live there are slimmer. I mean there are more slim people around there. You know why? They walk. Every day. As a part of their everyday routine, they walk to public transportation, to stores, to restaurants. Many people who live in Manhattan, or downtown Moscow do not have cars. It is more convenient to walk and use metro, then sit it traffic for hours. When I lived in Moscow. I had to walk 15 minutes to metro, after taking metro I had to chaise bus (you have to chaise bus in Moscow, derivers will not wait for you on the bus stop: they stop on the bus stop, let people go in and out and leave. If you are not at the stop at that time, they leave. Even if you are few yards away and they perfectly see you. You have to run to be on time. Otherwise you might need to wait for another bus for an hour. They also do not have schedules. You should see girls on 5-inch stilettos or grandmas running to catch the bus.
The main point I was walking everyday. Walking helped me to keep my weight down. Walking is a good exercise with low to medium impact.
Later while I was very big, walking was only one option to exercise for me. So I started slow. I also brought my dog from Russia. She was motivating me take walks every day.
When you are heavy any physical activity is harder. You have to carry all that weight with you. It is hard on your joints, bones, heart, lungs,, When I was dieting walking was only one type of exercise I did until I’ve lost about 80 pounds. I think swimming and water aerobics are pretty suitable for heavy people also. Water takes weight off and provides resistance for muscle toning.