Swimming does burn calories at a rate of about 3 calories a mile per pound of bodyweight. If you weigh 150 lbs. and it takes you 30 minutes to swim one mile (1,760 yards or 1,609 meters), then you will be using about 900 calories in one hour.
Another important area that grape seed extract can help is eye health. Grape seed extract is frequently recommended to combat macular degeneration, cataracts, and eye strain. Studies have shown that 300 mg daily reduces eye strain from prolonged computer use in 60 days.
As of now, grape seed extract may be available as a high blood pressure supplement but the best results can still be achieved if accompanied by lifestyle and diet changes. Embarking your faith on the sole use of grape seed extract for high blood pressure is an unhealthy decision.