Post-exercise nutrition is an important factor in a nutrition plan for physically active subjects. Focusing on that, the Serbian group is developing protein bars enriched with sports supplements. Slovenian partner group will investigate the effect of new protein bar consumption on body composition, biochemical parameters, and muscle regeneration after training. The new bar will be compared with a commercially available bar.

The clinical study will be performed on 10 elite handball players from Slovenia handball club. It will be designed as a crossover study. Half of the participants will consume the new bar for five days and the other half will consume the control bar. After the five-day washout period, the groups will consume the bar which was not consumed in the first period.

At baseline, at the end of every intervention and washout period, the blood samples will be withdrawn, and the body composition will be analyzed.

The analyzed biochemical parameters will be basic serum parameters, such as fasting glucose, total cholesterol, LDL, HDL, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), C-reactive protein (CRP), and parameters related to the muscle regeneration and inflammation, such as creatine kinase, lactate dehydrogenase, insulin-like growth factor (IGF), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), monocyte chemoattractant protein 1 (MCP-1).

In the second part of the study, the acute effect of consuming each bar after training will be tested. Each participant will consume both bars on separate days. The mentioned parameters will be assessed after training and immediately and 3h after bar consumption.

Inclusion Criteria:

• daily high-intensity physical activity

Exclusion Criteria:

• smoking, cardiovascular, neurological, skeletal muscle disease, allergies

Male

Other researchers on the study (Saša Kenig, Ana Petelin, Tadeja Jakus) will analyze samples, which will be coded by PI