Madrid, Aug 9 (IANS): Adolescence is the time when one needs to be particular about food consumption, especially intake of vitamins and minerals for a healthy life. But several studies have shown that adolescents' intake of important nutrients, as well as their performance in standard physical fitness tests, have fallen in recent years.

Because nutrition and fitness are intertwined -- for example, iron forms part of haemoglobin, which carries oxygen to muscles, and antioxidants such as vitamin C aid in rebuilding damage after intense training -- these two findings could be related, the Journal of Applied Physiology reports.

Luis Gracia-Marco of the University of Zaragoza, Spain, and colleagues, have found that adolescents' blood levels of various micronutrients are correlated with how well they performed in certain physical fitness tests.

Gracia-Marco and colleagues relied on data from a larger, long-term research project known as the Healthy Lifestyle in Europe by Nutrition in Adolescents Cross-Sectional Study, or HELENA-CSS, according to a Zaragoza statement.

Part of this study, which involved thousands of volunteers aged between 12.5 and 17.5 years in cities scattered across Europe, gathered nutrition and physical fitness data.

Researchers found that blood levels of certain micronutrients were closely connected with the volunteers' performance in physical fitness tests.

For cardiorespiratory fitness, concentrations of haemoglobin, retinol, and vitamin C in males and beta-carotene and vitamin D in females was linked with VO2max (peak oxygen uptake).

For muscular fitness, concentrations of haemoglobin, beta-carotene, retinol, and alpha-tocopherol in males and beta-carotene and vitamin D in females was associated with performing better on the standing long jump test.