Key pointsr Considerable controversy exists regarding the role of irisin, a putative exercise-induced myokine, in human metabolism.r We therefore studied irisin and its precursor Fndc5 in obesity, type 2 diabetes and exercise. r Complex clinical studies combined with cell culture work revealed that Fndc5/irisin was decreased in type 2 diabetes in vivo, but not in muscle cells in vitro, indicating that diabetes-related factor(s) regulate Fndc5/irisin in vivo.r Several attributes of type 2 diabetes, such as hyperglycaemia, triglyceridaemia, visceral adiposity and extramyocellular lipid deposition were negatively associated with adipose tissue Fndc5 mRNA and circulating irisin. Moreover, mimicking diabetic status in vitro by treating muscle cells with palmitate and glucose lowered Fndc5 mRNA.r Neither exercise training nor an acute exercise bout modulated circulating irisin or muscle Fndc5 expression. However, the associations between intensity of habitual physical activity, muscle volume, strength, contractility and circulating irisin provide a link between irisin and positive outcomes of increased physical activity.Abstract Irisin was identified as a myokine secreted by contracting skeletal muscle, possibly mediating some exercise health benefits via 'browning' of white adipose tissue. However, a controversy exists concerning irisin origin, regulation and function in humans. Thus, we have explored Fndc5 gene and irisin protein in two clinical studies: (i) a cross-sectional study (effects of type 2 diabetes (T2D) in drug-naive men) and (ii) an intervention study (exercise effects in sedentary, overweight/obese individuals). Glucose tolerance and insulin sensitivity were assessed. Maximal aerobic capacity and muscle strength were measured before and after training. Body composition (magnetic resonance imaging), muscle and liver fat content ( 1 H-magnetic resonance spectroscopy (MRS)) and in vivo muscle metabolism ( 32 P-MRS) were determined. Skeletal muscle and subcutaneous abdominal adipose tissue samples were taken in the fasted state and during euglycaemic hyperinsulinaemia (adipose tissue) and before/after exercise training (muscle). We found that muscle Fndc5 mRNA was increased in prediabetes but not T2D. tissue and irisin in plasma were reduced in T2D by 40% and 50%, respectively.

This review includes the latest findings based on experimental studies addressing sport-specific balance, an area of research that has grown dramatically in recent years. The main objectives of this work were to investigate the postural sway response to different forms of exercise under laboratory and sport-specific conditions, to examine how this effect can vary with expertise, and to provide examples of the association of impaired balance with sport performance and/or increasing risk of injury. In doing so, sports where body balance is one of the limiting factors of performance were analyzed. While there are no significant differences in postural stability between athletes of different specializations and physically active individuals during standing in a standard upright position (e.g., bipedal stance), they have a better ability to maintain balance in specific conditions (e.g., while standing on a narrow area of support). Differences in magnitude of balance impairment after specific exercises (rebound jumps, repeated rotations, etc.) and mainly in speed of its readjustment to baseline are also observed. Besides some evidence on an association of greater postural sway with the increasing risk of injuries, there are many myths related to the negative influence of impaired balance on sport performance. Though this may be true for shooting or archery, findings have shown that in many other sports, highly skilled athletes are able to perform successfully in spite of increased postural sway. These findings may contribute to better understanding of the postural control system under various performance requirements. It may provide useful knowledge for designing training programs for specific sports.

This review focuses on investigations into postural sway response to different forms of exercise, and particularly those dealing with physiological mechanisms of post-exercise balance impairment. The findings of relevant studies combined with our research results show that postural sway response to exercise depends on its type, intensity, duration and intensity of proprioceptive stimulation. Differences in postural sway were also observed after exercise with different forms of muscle contraction and those with different activation of muscle fibres. In general, fatigue is associated with post-exercise balance impairment. Such an effect is usually a consequence of prolonged exercise. However, findings proved that after short-term intensive exercises, hyperventilation, rather than fatigue, is responsible for increased postural sway. Significant differences in balance impairment were also found after exercises that induced the same ventilation but with a different intensity of muscle contractions eliciting a different level of proprioceptive stimulation, such as calf rises versus jumps and cycling versus running. Thus, in addition to fatigue and hyperventilation, impairment of somatosensory inputs also very likely plays a role in increased post-exercise postural sway. Based on this literature review, possible physiological mechanisms of post-exercise balance impairment identified so far may be fatigue, hyperventilation, deterioration of functions of mechanoreceptors, proprioceptors, vestibular apparatus and visual cues, muscle damage, dehydration, hyperthermia and dizziness. These findings can be explored in a more practical setting in the field of sport, clinical medicine and rehabilitation.

Relationship of body mass status with running and jumping performances in young basketball players s jumping test (Pmean) (p<0.001, η 2 ≥0.23) with older players presenting higher values. Within each age group, overweight players had higher BM, BMI, body fat percentage and FM (p<0.05) than their normal weight counterparts. Overweight players had worst performance in running (sprint and endurance) and jumping (CMJ and Pmean) in U-12, and worst endurance in U-18 (p<0.05, |d|≥0.82) than normal-weight players, whereas there was no difference in U-15. Conclusions: it was concluded that the relationship of BMI with running and jumping performances varied according to age. Based on these findings, trainers and coaches should focus on special intervention exercise and nutrition programs targeting optimal body mass especially in young basketball players, where the excess of body mass seemed to have the most detrimental effect on running and jumping performances.

The study evaluates the effects of a 4-week program of combined resistance and aerobic training and volleyball training on physical fitness in young sedentary adults. Twenty-eight males (age 20.5 ± 1.5 years; body mass 87.2 ± 28.5 kg; height 173 ± 8.1 cm; BMI 28.9 ± 8.4 kg/m2) were divided into two groups. While experimental group 1 (COM) underwent a fitness program consisting of a combination of strength and aerobic exercises, experimental group 2 (VOL) performed intermittent exercises in volleyball (four times per week for 50 min). The results showed that both training groups significantly improved in all fitness tests except the beep test, while only the COM group achieved a significant change in the number of repetitions (p = 0.041). Between-group analyzes revealed a greater change achieved by the COM group in standing long jump lengths than VOL (12.3% vs. 4.3%, p = 0.011). There were no other between-group significant differences in 20m Multistage Fitness Test (8.1% and 4.4%,), sit-ups (20.9% and 21.0%), flexibility (24.5% and 23.3%) and shuttle run 5 × 10 m (11.95 and 9.52%) or in anthropometric parameters (BMI, Fat %, Muscle Mass %, Visceral Fat %). These findings indicate that combined resistance and aerobic training are more effective in improving the explosive power of lower limbs and aerobic endurance than playing an intermittent-type sport such as volleyball. This program can be effectively applied to university students with a predominantly sedentary lifestyle.

Samples of Hyperici herba were obtained by harvesting Hypericum perforatum L. in different plant development stages. The relation of flower development phases in the drug's flower fraction was examined. The HPLC method was then employed for the analysis of the content of secondary metabolites in different flower ontogenesis phases. The content of dianthrones, derivatives of quercetin and hyperforin increased from the first bud phases (0.29%, 0.80%, and 2.47%, respectively) to flowers just opened (1.04%, 4.23% and 6.60%, respectively). The content of dianthrones and quercetin glycosides then decreased (in unripe fruits 0.11% and 0.08%, respectively), whereas the amounts of hyperforin increased to 8.07% in fruits. The content of I3,II8-biapigenin increased from 0.21% in small buds to 1.04% in buds just before opening and has then decreased gradually to a value of 0.02% in fruits. Rutin was not detected in the samples.

Phosphorus magnetic resonance spectroscopy ((31)P-MRS) enables the non-invasive evaluation of muscle metabolism. Resting Pi-to-ATP flux can be assessed through magnetization transfer (MT) techniques, and maximal oxidative flux (Q(max)) can be calculated by monitoring of phosphocreatine (PCr) recovery after exercise. In this study, the muscle metabolism parameters of 13 overweight-to-obese sedentary individuals were measured with both MT and dynamic PCr recovery measurements, and the interrelation between these measurements was investigated. In the dynamic experiments, knee extensions were performed at a workload of 30% of maximal voluntary capacity, and the consecutive PCr recovery was measured in a quadriceps muscle with a time resolution of 2 s with non-localized (31)P-MRS at 3 T. Resting skeletal muscle metabolism was assessed through MT measurements of the same muscle group at 7 T. Significant linear correlations between the Q(max) and the MT parameters k(ATP) (r = 0.77, P = 0.002) and F(ATP) (r = 0.62, P = 0.023) were found in the study population. This would imply that the MT technique can possibly be used as an alternative method to assess muscle metabolism when necessary (e.g. in individuals after stroke or in uncooperative patients).

Background: There is a need for effective and early functional rehabilitation of patients with gait and balance problems including those with spinal cord injury, neurological diseases and recovering from hip fractures, a common consequence of falls especially in the elderly population. Gait training in these patients using partial body weight support (BWS) on a treadmill, a technique that involves unloading the subject through a harness, improves walking better than training with full weight bearing. One problem with this technique not commonly acknowledged is that the harness provides external support that essentially eliminates associated postural adjustments (APAs) required for independent gait. We have developed a device to address this issue and conducted a training study for proof of concept of efficacy.