Hi Nandita,
Whatever activity we choose, the key is to commit to doing it regularly. Correct timing should be applied to an exercise to lose weight. One should also maintain a high heart rate for sustained periods of time. Moderately intense activity or exercise should increase the heart and breathing rates and possibly lead to a lights sweat but it differs from person to person. Initial fitness goal should be to do 30 min of exercise each day. Thereafter, gradually increase this to about 60 min of exercise per day. The best combination of exercise is a mixture of aerobic and strength training. Aerobic and strength training exercises both assist weight loss but in different ways.