Dear Peter Griepink

Thank you very much your answer .

Here I posted Prof. Susan M. Kleiner;s article ( SSE#58, Volume 8 (1995), Number 5 ) we can find more points about the subjects

Susan M. Kleiner, Ph.D., R.D. High-Performance Nutrition Mercer Island, Washington KEY POINTS

1. In the typical Western diet, meats such as beef, lamb, pork, veal, poultry, and fish are the predominant sources of protein, B vitamins, iron, and zinc.

2. Iron and zinc are the two nutrients most often deficient in vegetarian or modified-vegetarian diets. Also, iron and zinc are the most cited nutrients that may be deficient in the diet of athletes.

3. Athletes who choose to exclude meat from their diets must carefully plan diets to enhance nutrient availability, particularly for iron and zinc

https://www.gssiweb.org/en/sports-science-exchange/Article/sse-58-the-role-of-red-meat-in-an-athlete's-diet

Please take a look at this useful RG link.

Article Vegetarian Diet and Athletes

Vegetarian diets do not compromise athletic performance and may even help aerobic capacity, according to a study comparing elite vegetarian and omnivore athletes.