Background/Objectives: Physical activity is widely recognized for its beneficial effects on bone density during adolescence, which could lead to enhanced bone density in later life, thus acting as a health-promoting activity with long-lasting implications. However, not all studies are conclusive regarding the type, intensity, duration, and frequency of the most effective physical activities. This study focuses on combat sports athletes and examines the relationship between their somatic build and heel bone parameters using ultrasound (USG) and their vitamin D3 levels. Methods: The study included 40 male athletes specializing in various combat sports. The measurements of body height, body mass, skinfold thickness, and bone widths at multiple sites were performed to estimate the somatic build. The USG parameters of the heel bone and the blood levels of vitamin D3 were also recorded. Statistical significance was determined using one-way ANOVA, with differences among sports disciplines also examined. Results: The study found significant differences in the body composition and USG bone parameters among athletes from different combat sports (p ≤ 0.05). The calcaneus stiffness index (SI) and speed of sound (SOS) were significantly higher in athletes with normal vitamin D3 levels compared to those with below-normal levels (p = 0.0015 and p = 0.001, respectively). These findings suggest that vitamin D3 may influence bone stiffness and density. Conclusions: The study underscores the importance of maintaining adequate vitamin D3 levels to support bone mineralization in athletes, particularly those training indoors with limited exposure to sunlight. It also highlights the potential of using USG as a non-invasive method to assess bone health, aiding in the optimization of training programs to prevent injuries and improve performance.

Background/Objectives: Mandelic acid as a chemical peel has been used in cosmetology for years and is being gradually exchanged for lactobionic acid. However, in the cosmetology literature, there is no information on the effectiveness of the aforementioned peels in terms of hydration and elasticity for women’s facial skin depending on their age. The effects of lactobionic and mandelic acid on the skin of women aged 30–40 and 50–60 years are assessed in terms of their moisturizing and elasticizing effects. Methods: The participants of this study were 180 women aged 30–40 and 50–60 years. The selection of the group was random. Contraindications to the examination were excluded in all participants. The level of hydration was assessed using Tewameter and the level of elasticity using a cutometric probe (Courage-Khazaka Multi Test Skin Center MC 1000, Kőln, Germany). The participants also used a moisturizer. Moreover, a series of five exfoliating treatments using 40% mandelic acid or 40% lactobionic acid were performed in 120 of the participants. After 14 days since the last treatment, the assessment of their facial skin’s hydration and elasticity was performed yet again. Results: In the case of women aged 30–40 years, the level of hydration and elasticity increased after using lactobionic and mandelic acid, as well as a moisturizer. In the group of older women aged 50–60 years, the level of elasticity increased after using both acids and moisturizer, but the hydration parameter increased only after the usage of lactobionic acid and moisturizer. Conclusions: In terms of age, lactobionic acid will be more suitable for people aged 50–60, while for women aged 30–40, lactobionic or mandelic acid can be used.