Importance of pH: Health, sports and fitness performance, and nutrition

Importance of pH: Health, sports and fitness performance, and nutrition

Do you know the pH of different foods? Understanding this concept is essential for staying in excellent health and achieving great performance

What is pH?

pH stands for “hydrogen potential”. It refers to the grade of hydrogen ions in a substance or a solution. The body’s pH is really important as it controls the speed at which the biochemical reactions that take place in your own body.

pH scale

pH is measured on a scale from 1 to 14 and shows the acidity of a substance:

  • pH<7: Acid The greater the acidity, the lower the pH will be. This allows for the increase of positive ions which aid the transmission of electric impulses in the body
  • pH = 7: Neutral
  • pH>7: Alkaline or basic The lower the acidity, the more basic (or alkaline) the substance will be. The higher the pH is (more alkaline) in a given substance, the more electrical resistance it will have (fewer positive ions) As a result of this, electricity will travel at a slower speed

Scale 2

pH and your health

To guarantee an adequate working of metabolic processes and the transportation of oxygen to all organs, our body needs the blood’s pH to be (between 7.34-7.45).

In the case of an imbalance in our pH, our body will try to reestablish the natural balance at all costs.

Excess levels of acid create an environment that favours decomposition of cells, disabling the body’s systems and allowing access to different illnesses (lower biological defenses).

The downside is that in order to do this, the body will take minerals from our bones (osteoporosis) and blood vessels (associated with arteriosclerosis ).


For example, if the acidity in our blood increases, therefore reducing pH to 6.5, our body will start to look for ways to obtain and store minerals (mainly calcium, carbonate and magnesium) in order to recover its neutrality.

Cholesterol associated with pH

To counter the loss of calcium in the walls of our blood vessels, the body replaces it with cholesterol (more resistant to acid ), making the wall firmer. The problem persists when the situation becomes constant and the body starts producing more cholesterol in its effort to combat these effects.

Therefore, cholesterol levels become a defense against acidic pH and should be cured with a balancing of diet (see nutrition section).

pH and fitness performance

There is a significant controversy and debate about whether changing internal pH conditions favours sport and fitness performance. This is especially true for activities involving a large anaerobic component

Additionally, if we look at the role of sports medicine, there are many professionals that consider lactate as the key factor when it comes to possible increase in acidosis when training at high intensity. If it falls below a certain grade of acidity, an inhibition of the different enzymatic systems is produced. It is important to remember that these systems participate in the supply, and therefore, cause an interruption in muscle training.

This is known as a muscle burn-out (metabolic fatigue) which makes it impossible for us to continue with the next rep of our current set


In this aspect, a trained sportsperson has a higher tolerance to acidification compared to a person who isn’t trained professionally. As a result of this training, their pH needs to get a lot lower for them to feel fatigued.

Metabolic acidosis

The occurrence of metabolic acidosis over a significant length of time has a series of negative consequences on the body that can be a disadvantage when striving for athletic performance and results, or increased muscle mass.

  • Causes loss of muscle mass, due to a negative hydrogen balance reflected in an increase of nitrogen loss in urine. This is mainly due to the body using glutamine when it tries to buffer internal acidification. As we already know, muscle is the main store of glutamine, which is why this results in a catabolic process in the muscle.
  • Causes blocking of normal anabolic processes that take place in the body through a decrease in the activity of an anabolic factor known as IGF-1, resulting in an increase in resistance to the growth hormone and an increase in cortisol levels.
  • Could potentially cause aslowing down of the basal metabolism of an individual through a light case of hypothyroidism.

pH y nutrition

Ketogenic diets

It has been demonstrated that Ketogenic diets (high in fats and proteins and low in carbohydrates) have been associated with lower and more acidic blood pH values than diets high in carbohydrates (around 70%), where values are more basic and therefore of greater benefit if doing sports or training.

Cetogenic diet

Typical foods on the ketogenic diet

On the subject of whether this diet can be carcinogenic due to the high consumption of animal products involved, it seems that nothing could be further from the truth, as these diets have shown to be Ketogenic diets efficient not only in the reduction of tumor size but also in preventing the weight loss associated with cancer.

Carbohydrate loading

Carbohydrate loading after doing physical exercise , benefits the basic blood level . However, the opposite occurs when physical exercise is followed by a low carbohydrate diet.

Even without producing changes to levels of glycogen, when subjects were studied and given a 3–4 day ketogenic diet, performance results for low duration exercises were worse, despite amounts of lactate in the blood being lower.


We could therefore come to the conclusion that the most impacted sports would be those that produce metabolic acidosis (high intensity, short duration)

On the other hand, in the case of aerobic exercises, ketogenic diets could be of great use in terms of performance, enabling the athlete a better use of fats for energy, considering that it is the main source of energy during these activities, with the exception of sprinting.

Things to take into account and advice

  • Optimum hydration (water is the main component of our cells). At least 3 litres of water a day in case of inactivity which could increase to 4.5 litres a day for a highly active sportsperson. If the water is spring water or alkaline water (filtered or with lemon juice ) this will provide even better hydration.Fruits vegetables
  • Fruit and vegetables are of excellent benefit, not just because of their vitamin, mineral, fibre and antioxidant content. A great, and often overlooked benefit, is the improvement of acid-basic (alkaline) balance of the internal environment and therefore favouring recovery after burn-out situations where increased acidity has occurred. In ketogenic diets, vegetables can be an excellent ally to help avoid acidosis caused by proteins and fats.
  • Exercise causes us to lose electrolytes, which are essential for nervous system impulses and contraction or flexing of muscles. For this important reason, replacing them as quickly as possible is essential for optimum functioning of the body .
  • The 70/30 rule – 70% of a healthy diet should come from the alkaline groups.


Despite not being scientifically referenced, stress is one of the most significant causes of acidity in the body. That’s why it’s all the more important to take some time out of your day for deep breathing exercises and relaxation.


  1. Buclin T et al. Diet acids and alkalis influence calcium retention in bone. Osteoporos Int. 2001; 12:493-9.
  2. Lambert EV et al. High-fat diet versus habitual diet prior to carbohydrate loading: effects on exercise metabolism and cycling performance. Int J Sport Nutr Exerc Metab. 2001; 11:209-25.[Medline]
  3. Pérez-Guisado J. Arguments in favor of ketogenic diets. The Internet Journal of Nutrition and Wellness. 2007; 4:2.
  4. Pérez-Guisado J. Hidratos de carbono, metabolismo de la glucosa y cáncer. Endocrinología y Nutrición. 2006; 53:252-5.
  5. Pérez-Guisado J. Las dietas cetogénicas: beneficios adicionales a la pérdida de peso y efectos secundarios infundados. Alan. 2008; 58:. en prensa
  6. Pérez-Guisado J. Las dietas cetogénicas: fundamentos y eficacia para la pérdida de peso. Alan. 2008; 58:126-31.
  7. Pérez-Guisado J. Rendimiento deportivo: glucógeno muscular y consumo proteico Apunts. Medicina de l’Esport. 2008; 43:142-51.
  8. Pérez-Guisado J. Sportsmen and pH: the importance of lactate and diet. Apunts. Medicina de l. 2010;45:103-7
  9. (Visitada por última vez el 26 julio 2013)

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  • How does lactate affect sports and fitness performance?
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About Mario Muñoz
Mario Muñoz
Mario Muñoz is an enthusiast in the field of research, as reflected in each of his articles published with excellent scientific rigour.
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