In this study, we investigated the effects of resistance training protocols with different loads on muscle hypertrophy and strength. Twenty-one participants were randomly assigned to 1 of 3 (n = 7 for each) resistance training (RT) protocols to failure: High load 80 % 1RM (8–12 repetitions) (H group), low load 30 % 1RM (30–40 repetitions) (L group) and a mixed RT protocol (M group) in which the participants switch from H to L every 2 weeks. RT consisted of three sets of unilateral preacher curls performed with the left arm 3 times/week with 90 s rest intervals between sets. The right arm served as control. Maximum voluntary contraction (MVC) of the elbow flexors (elbow angle: 90°) and rate of force development (RFD, 0–50, 50–100, 100–200 and 200–300 ms) were measured. Cross-sectional area (CSA) of the elbow flexors was measured via magnetic resonance imaging (MRI). All measurements were conducted before and after the 8 weeks of RT (72–96 h after the last RT). Statistical evaluations were performed with two-way repeated measures (time × group). After 8 weeks of 3 weekly RT sessions, significant increases in the left elbow flexor CSA [H: 9.1 ± 6.4 % (p = 0.001), L: 9.4 ± 5.3 % (p = 0.001), M: 8.8 ± 7.9 % (p = 0.001)] have been observed in each group, without significant differences between groups. Significant changes in elbow flexor isometric MVC have been observed in the H group (26.5 ± 27.0 %, p = 0.028), while no significant changes have been observed in the M (11.8 ± 36.4 %, p = 0.26) and L (4.6 ± 23.9 %, p = 0.65) groups. RFD significantly increased during the 50–100 ms phase in the H group only (p = 0.049). We conclude that, as long as RT is conducted to failure, training load might not affect muscle hypertrophy in young men. Nevertheless, strength and RFD changes seem to be load-dependent. Furthermore, a non-linear RT protocol switching loads every 2 weeks might not lead to superior muscle hypertrophy nor strength gains in comparison with straight RT protocols.

Low testosterone and its symptoms is a condition affecting many males with severe repercussions on health. Testosterone affects metabolism, bones, joints and ligaments, the cardiovascular system, l...

Testosterone is crucial in regulating several body functions in men, including metabolic, sexual, and cardiovascular functions, bone and muscle mass, and mental health. Therefore, optimizing testosterone levels in men is an important step to maintaining a healthy body and mind, especially as we age. However, traditional testosterone replacement therapy has been shown to lead to male infertility, caused by negative feedback in the hypothalamic–pituitary–gonadal (HPG) axis. Recent advances in research have led to the discovery of many new methods of administration, which can have more or less suppressive effects on the HPG axis. Also, the usage of ancillary medications instead of or after testosterone administration might help maintain fertility in hypogonadal patients. The goal of this narrative review is to summarize the newest methods for optimizing fertility parameters in patients undergoing treatment for hypogonadism and to provide the necessary information for healthcare providers to make the right treatment choices.

The occurrence of the metabolic syndrome and its related diseases such as diabetes are steadily rising in our modern society. Modern food choices and the more sedentary lifestyles largely contribute to this shift in our society’s health. Fasting has been practiced for religious purposes all over the world long time before science showed the benefits of it. The effects of fasting on glucose and fat metabolism are of great interest. Fasting triggers a cascade of changes in the hormonal, microbiome and enzymatic environments, leading to shifted glucose and fat metabolisms. Fasting-induced metabolic function changes are affected by several factors such as sex hormones, lipid-released hormones, growth hormone, insulin, and the gut microbiome, leading to lipolysis and the release of FFA into the bloodstream. The purpose of this review is to summarize the newest research results on the specific pathways fasting triggers to improve metabolic functions and understand the potential applications of fasting as prevention/treatment of several metabolic conditions.

Testosterone replacement therapy is a promising and growing field in modern healthcare. Several novel testosterone preparations aiming at providing an efficient drug without side effects have been developed in recent years. Several oral, nasal, gel, and self-injection preparations are now available, providing a wide variety of options customized to each individual’s needs. We searched Google Scholar for keywords related to the different types of testosterone replacement therapy. This review provides information about the benefits and side effects of the newest testosterone preparations, aiming at giving a summary of the options with regard to testosterone replacement therapy to healthcare professionals. As testosterone replacement therapy is increasing in popularity, the development of novel ways of administration minimizing side effects associated with testosterone replacement therapy is growing. Nowadays, hypogonadal patients have several options to treat their conditions and can choose the most beneficial method for their individual condition.