Marta Montenegro: Can Your Diet Boost Aerobic Capacity?

If your goal is to finish a marathon you think carbohydrates. If your goal is to increase body mass then lean protein rich food sources and healthy fats come to mind. But is there a diet that specifically boosts aerobic capacity?

Improving your aerobic capacity means greater oxygen delivery to your muscles, which translates to a fitter you. Unfortunately, your maximum oxygen uptake (VO2max) is affected by many variables you can and cannot control, such as exercise mode, genetics, body mass-body fat ratio, and gender.

So far the diet composition impact on measuring VO2max has remained questionable. However, a new study published in the Medicine & Science in Sports & Exercises showed that participants who favored an alkaline-type diet showed a greater peak value for maximal-exercise (RERmax) during maximal-intensity exercise testing.

An alkaline diet means that one-third of your total calories come from vegetables, non-sweet citrus fruits, sprouted seeds, nuts, and some grains. Alkaline foods increase your blood pH number, which indicates how acidic is your blood. This in effect reflects how many free hydrogen ions are in the blood, explains Edward Weiss, Ph.D. a professor in Kinesiology at Saint Louis University. Hydrogen ions accumulate when oxygen energy demands cannot be met at the same rate your body needs. When they are high you tire quicker and your blood pH becomes more acidic.

The pH – Exercise Relationship

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High intensity exercise, such as running a 400-meter track event, produces a lot of acid in your blood and temporarily decreases pH levels. “This is why we have to stop running and cannot continue at the 400 meter pace for a longer distance,” says Weiss. “Exercise must stop because the temporary accumulation of acid drop in pH interferes with the chemistry that converts food into fuel that the muscles use. This is mainly an issue for maximal effort exercise that lasts approximately 1 to 5 minutes.”

Keep in mind that this drop in blood pH is normal and the body quickly corrects it within a few minutes of recovery.

An alkaline prone type of diet affects aerobic capacity by helping the kidney and other buffering systems—such as the lymphatic system and alkaline salts like sodium, potassium, calcium and magnesium—maintain a better pH even in an acidic environment like during high intensity exercise. If you can maintain a more alakaline diet, you may experience less of the normal pH drops that happens during high intensity exercise. This may help to boost your aerobic capacity.

Surprising “Acidic” Habits

Your blood acidic conditions can be exacerbated by other dietary and lifestyle habits. Drinking a lot of coffee and soda and not drinking enough water, having a high processed food intake, and consuming low amounts of produce, all can affect pH levels. “Not getting enough sleep or proper rest after workouts also affects pH,” says Nolan. “Exercise causes lactic acid buildup in the muscles, and without proper rest, hydration, and nutrition the lactic acid is not properly flushed out and can cause an acidic environment in the body.”

What is the “right” pH blood level? “It should be maintained at 7.4,” says Marjorie Nolan, MS, RD, CDN, ACSM-HFS, national spokesperson for the Academy of Nutrition & Dietetics,  Your body does a good job to keep your pH at this level, but your diet can affect this number. An alkaline food plan can ensure you maintain this number and possibly  boost aerobic capacity.

Alkaline Shopping Bag

Keeping up an alkaline diet is easy. Most of the key foods are part of a regular health-based diet. On your next grocery trip fill up your cart with 60 to 80 percent low acidic foods, such as spinach, cantaloupe, sweet potato, lentils, broccoli, onions, watermelon, pumpkin seeds, kiwi, apricots, and very low acidic options like amaranth, brown rice, chicken, and pine nuts.