Impact of marathon performance on muscles stiffness in runners over 50 years old

IntroductionThe research examines the relationship between marathon performance and muscle stiffness changes from pre to marathon in recreational runners aged 50+ years.MethodsThirty-one male long-distance runners aged 50–73 years participated in the experiment. The muscle stiffness of quadriceps and calves was measured in two independent sessions: the day before the marathon and 30 min after the completed marathon run using a Myoton device.Results and DiscussionThe 42.195-km run was completed in 4.30,05 h ± 35.12 min, which indicates an intensity of 79.3% ± 7.1% of HRmax. The long-term, low-intensity running exercise (marathon) in older recreational runners and the low level of HRmax and VO2max showed no statistically significant changes in muscle stiffness (quadriceps and calves). There was reduced muscle stiffness (p = 0.016), but only in the triceps of the calf in the dominant (left) leg. Moreover, to optimally evaluate the marathon and adequately prepare for the performance training program, we need to consider the direct and indirect analyses of the running economy, running technique, and HRmax and VO2max variables. These variables significantly affect marathon exercise

Production of phosphorus biofertilizer based on the renewable materials in large laboratory scale

This paper discusses the effect of the utilization of Bacillus megaterium in the microbial solubilization process where poultry bones or ash were used as a source of renewable phosphorus. The process was performed in a large scale laboratory. The pH of the solution decreased during one-week solubilization, which had a direct influence on the increased concentration of phosphorus determined in the solution. It was proved that the phosphorus concentration in the solution was significantly correlated with the biomass concentration and pH. The trial allowed verification of the suitability of the method to prepare two P fertilizers: one based on poultry bones and one on ashes. The elemental analysis of their composition suggests that the bones are a P-bearing resource with properties better than ash. That enables for more efficient scaling-up the solubilization although the concentration of total phosphorus was comparable in both cases. The total amount (100%) of phosphorus was present in a form available to plants in the formulation based on the poultry bones, while 64% of plant available phosphorus was present in the formulation based on the ash. The concentration of Cd was significantly lower in the case of fertilizer based on bones with respect to ash

Valorization of Phosphorus Secondary Raw Materials by Acidithiobacillus ferrooxidans

This paper presents the possibility of producing phosphorus fertilizers through Acidithiobacillus ferrooxidans utilization in secondary raw materials solubilization. Phosphorus was obtained from the bones of poultry and fish as well as from Morocco phosphorite. Four doses of poultry bones and fish bones were used in the experiment (2, 4, 10 and 20 g/L) and two doses (2 and 4 g/L) of phosphorite were also used. The experimenters measured the final pH, which increased in proportion to the increase in the number of poultry bone doses, whereas in the case of fish bones it decreased in proportion to the increase in the number of fish bone doses. Only in the case of phosphorite, where 10 g/L were used, there was a slight increase in pH during solubilization observed. The highest phosphorus concentration of 1.9% (expressed as P2O5) was found for the solubilization performed on fish bones with the highest dose (20 g/L). The formulation obtained in this study meets the necessary requirements for use as a bio-fertilizer because of the relatively low content of P2O5 and the low content of toxic elements. The results confirm the utilization of Acidithiobacillus ferrooxidans in the biosolubilization of phosphorus renewable raw materials that can alleviate the problem of the world’s depleting phosphorite deposits