Abstract
The development of new plant extract products is currently an important strategy in the field of improving sports performance and nutritional prevention strategies for muscle deconditioning during aging. Currently, physical exercise based primarily on aerobic exercise at medium intensity remains the most effective prevention strategy for muscle deconditioning during aging. However, only 50% of adults aged 65 and over meet the requirements for aerobic physical activity due to lack of time. This suggests that there would be greater participation in exercise modalities requiring less practice time but resulting in similar effects. During this thesis work, we therefore explored in a first study the ergogenic effects of a combination of plant extracts (Rhaponticum carthamoides and Rhodiola Rosea) in a resistance exercise model in young rats. Our results mainly showed that this combination of plant extracts increased physical performance in response to resistance training compared to the same training alone. Our results showed that this could go through the anabolic effects of our plant extracts. Based on these results, we analyzed by a candidate molecule approach two active ingredients (20-hydroxyecdysone and salidroside) which could mediate these effects. At the same time, we have developed a High Intermittent Intensity Training (HIIT) to observe an acute increase in protein synthesis. The objective was to combine this exercise with one of the active ingredients contained in our plant extracts as a prevention strategy for muscle deconditioning during aging. Following experimental developments, we tested in aging mice a prevention strategy based on HIIT training associated with salidroside supplementation. Our main results showed that this strategy was effective in maintaining aerobic qualities, grip strength and limit body fat gain. These results could at least be explained by better vascularization as well as changes in aerobic metabolism. In conclusion, this thesis work contributes to the advancement of knowledge concerning the anabolic potential of Rhaponticum carthamoides and Rhodiola Rosea plant extracts on strategies for preventing muscle deconditioning.