A gym session can make you feel tired and hungry while yoga revitalises you and helps in digestion. While yoga has its distinct pluses, barring the odd exceptions (e.g. power yoga), yoga does not provide the cardiovascular benefits, which are so vitally important to all human beings. Fat loss and weight loss is not achieved through yoga, this is derived from cardio activities. Cardio activities could include aerobics, walking, jogging, cycling, rope skipping, dancing and swimming."
For ideal results, it is best to combine three to four days of cardio with two to three days of yoga, each week. The two can complement each other nicely. Space out your workout days. Keep one day a week for rest. Watch your diet and lifestyle to derive the best results.