This study aimed to 1) analyze the energy requirement (VO2eq) and the contribution of the aerobic (VO2ex), anaerobic alactic (VO2al), and anaerobic lactic (VO2la-) energy sources of a simulated intervention; 2) ascertain differences in mean VO2 and heart rate (HR) during firefighting tasks; and 3) verify the relationship between time of job completion and the fitness level of firefighters. Twenty Italian firefighters (age = 32 ± 6 yr, VO2peak = 43.1 ± 4.9 mL·kg·min) performed 4 consecutive tasks (i.e., child rescue; 250-m run; find an exit; 250-m run) that required a VO2eq of 406.26 ± 73.91 mL·kg (VO2ex = 86 ± 5%; VO2al = 9 ± 3%; VO2la- = 5 ± 3%). After 30 minutes, the recovery HR (108 ± 15 beats·min) and VO2 (8.86±2.67mL·kg·min) were higher (p < 0.0001) than basal values (HR = 66 ± 8 beats·min; VO2 = 4.57 ± 1.07 mL·kg·min), indicating that passive recovery is insufficient in reducing the cardiovascular and thermoregulatory strain of the previous workload. Differences (p < 0.001) between tasks emerged for mean VO2 and HR, with a lack of significant correlation between the time of job completion and the firefighters' aerobic fitness. These findings indicate that unpredictable working conditions highly challenge expert firefighters who need adequate fitness levels to meet the requirements of their work. Practically, to enhance the fitness level of firefighters, specific interval training programs should include a wide variety of tasks requiring different intensities and decision-making strategies.

Social isolation has adverse effects on mental health, physical exercise, and dietary habits. This longitudinal observational study aimed to investigate the effects of mood states and exercise on nutritional choices, on 176 college students (92 males, 84 females; 23 ± 4 years old) during the COVID-19 lockdown. During 21 days, nutrition and exercise were daily monitored, and the mood states assessed. A factor analysis was used to reduce the number of nutritional variables collected. The relationships between exercise, mood and nutrition were investigated using a multivariate general linear model and a mediation model. Seven factors were found, reflecting different nutritional choices. Exercise was positively associated with fruit, vegetables and fish consumption (p = 0.004). Depression and quality of life were, directly and inversely, associated with cereals, legumes (p = 0.005; p = 0.004) and low-fat meat intake (p = 0.040; p = 0.004). Exercise mediated the effect of mood states on fruit, vegetables and fish consumption, respectively, accounting for 4.2% and 1.8% of the total variance. Poorer mood states possibly led to unhealthy dietary habits, which can themselves be linked to negative mood levels. Exercise led to healthier nutritional choices, and mediating the effects of mood states, it might represent a key measure in uncommon situations, such as home-confinement.

Puberty influences both the performance and the hormonal responses to exercise-related stress. We evaluated the distribution and the correlation between pubertal characteristics and the salivary cortisol (sC) and testosterone (sT) responses to acute physical exercise in young male athletes (13.4 +/- 2.1 yr, n = 110). The mean pre-exercise nmol . L (-1) sC and sT concentrations were 19.08 +/- 4.32 and 0.34 +/- 0.15 and increased to 21.27 +/- 5.51 and 0.41 +/- 0.16 after a 90-min training session (p < 0.01). The sC concentration at rest was positively correlated with chronological age (p < 0.01) and negatively correlated with fat % (p < 0.05), whereas significant negative correlations of DeltasC and DeltasC% after exercise with age, pubertal stage and mean testis volume (p < 0.05) were observed. The sT increase after exercise was correlated with chronological age, pubertal stage and pre-exercise sT levels (p < 0.01), whereas the DeltasT and DeltasT% of increase were negatively correlated with chronological age and resting sT levels (p < 0.05 and p < 0.01). In the present study, we observed the presence of high inter-individual variability of different biological parameters (anthropometry, pubertal stage, hormones, etc.) within athletes selected by chronological age in the same class and the presence of significant correlations between chronological age, puberty and the steroid hormone responses to physical exercise. Our data suggest the need for different criteria in exercise prescription and selection of young athletes and in the evaluation of stress reactivity at puberty.

The aim of this study was to evaluate the effects of a simulated firefighting intervention on salivary alpha-amylase (sA-A), free cortisol (sC), anxiety (STAI), and profile of mood states (POMS) in 20 male firefighters (age 32 +/- 1 years, VO(2peak): 43 +/- 5 ml/kg per min). During the 12-min firefighting intervention (ambient temperature: 13 +/- 1 degrees C; relative humidity: 63 +/- 1%), individuals spent 63 +/- 28% of the time working at heart rate (HR) >85% of individual HR(max), [La] (peak) 9.2 +/- 2.9 mM and ratings of perceived exertion 16 +/- 2. At 30 min post-intervention significant (p < 0.001) increases in sA-A (174%) and sC (109%) were found with regard to values recorded before and after 90 min of the firefighting intervention. Since no differences emerged between pre-intervention and post intervention for STAI and POMS values, the hormonal changes were attributable to the intense physical stress of the simulated intervention. Further research is needed during real firefighting activities, where high emotional stress may also be present.

This study aimed at verifying whether chronic participation in soccer training has a beneficial effect (p < 0.05) on the improvement and the maintenance of interlimb coordination performance across the lifespan and whether coordination is moderated by strength and power performances. Forty young (12 +/- 1 yr), 42 adult (26 +/-5 yr), and 32 older (59 +/- 11 yr) male soccer players and sedentary individuals were administered in-phase (IP) and antiphase (AP) synchronized (80, 120, and 180 bpm) hand and foot flexions and extensions, handgrip and countermovement jump (CMJ) tests. Regardless of age, soccer players always showed better performances (handgrip: 383 +/- 140 N; CMJ: 28.3 +/- 8.7 cm; IP: 55.2 +/- 12.9 s; and AP: 31.8 +/- 25.0 s) than sedentary individuals (handgrip: 313 +/- 124 N; CMJ: 21.0 +/- 9.4 cm; IP: 46.7 +/- 20.2 s, and AP: 21.1 +/- 23.9 s). With respect to IP and AP performances, a hierarchical model (p < 0.0001) emerged for CMJ, explaining 30% and 26% of the variance for IP and AP, respectively. In contrast, handgrip did not provide increments in the explained variance. Results indicate that chronic soccer training is beneficial to develop strength, CMJ, and interlimb synchronization capabilities in children, to reach higher levels of proficiency in adults, and to maintain performance in older individuals. The predicted role of CMJ on interlimb coordination indicates that a fine neuromuscular activation timing is central for both jump and coordinative performances. In practice, to induce higher attentional control and executive function in open skill sport athletes and to better prepare players to cope with the demands of their match, coaches should modulate complex motor behaviors with increasing velocity of execution and are strongly recommended to make use of technical and tactical drills that focus on the player's agility under time pressure to induce higher attentional control and executive function.