Exercise Efficiency and NitratePosted: July 23, 2011
I came across an article recently which talked about beetroot juice & its effects on performance. We all know beetroot to be naturally high in nitrates as well as other leafy greens.
So beetroot juice as a sports supplement?
Previous studies looked at how beetroot juice effected the oxygen kinetics and/or its effect on exercise capacity. What this article divulged into was whether or not it actually improved performance.
The study was completed on cyclists over 4 exercise trials. So basically athletes were given either 500mL of beet juice or placebo 2.5hrs before each time trial. Although the amount of nitrate used in this study was 6.2mmol ( ie; 4-12 times more than the typical daily nitrate intake) this is approx 1.6kg of spinach or 3.1kg of lettuce. So if you plan on consuming that amount of nitrate before training….you would need to ingest 1/2litre of beetroot juice.
Just a heads up in this study the researchers did not alter/limit nitrate intake in each of the athletes existing diet. Secondly athletes did not use antibacterial mouthwash & chewing gum in the 2.5hrs prior to time trial (as these inhibit the oral bacteria necessary for the conversion of nitrate to nitrate).
Results: Athletes performance improved! Consuming beetroot juice increased plasma nitrate levels by 138%, the beet juice also decreased systolic blood pressure.
The study suggests that the its possible that the supplementation of nitrates improved ‘muscle contractile efficiency by decreasing total ATP turnover and other energy important metabolites’.
FYI: Classification of Vegetable according to Nitrate content ( mg/100g Fresh Weight)
Very Low (<20) Artichoke, Asparagus, Broad Bean, Eggplant, Garlic, Onion, Green Bean, Mushroom, Pea, Pepper, Potato, Summer Squash, Sweet Potato, Tomato, Watermelon.
Low (20 to <50) Broccoli, Carrot, Cauliflower, Cucumber, Pumpkin, Chicory.
Middle (50 to <100) Cabbage, Dill, Turnip, Savoy Cabbage.
High (100 to <250) Celeriac, Chinese Cabbage, Endive, Fennel, Kohlrabi, Leek, Parsley.
Very High (>250) Celery, Cress, Chervil, Lettuce, Red Beetroot, Spinach, Rocket.
Good thing I enjoy beets so much, I guess ill be chugging down some beet juice before training 🙂