No abstract

The immune system's response against SARS-Cov-2 seems crucial to control viral infection, since this system is homeostatic, dynamic and promotes immunoprotection of the organism through the activation of the innate and adaptive immune system via activation of cellular and chemical complexes that recognize, neutralize, metabolize and eliminate heterologous substances, with or without tissue damage. An obesogenic microenvironment can further increase the risk of disease complications, and cause a more virulent viral strain and a more lethal virus. Moreover, physical inactivity as well as poor eating habits impairs the body's energy metabolism and immune cells due to low-grade chronic inflammation. Studies suggest that light to moderate exercise, as well as mild calorie restriction, as an effective approach to relieve obesity and therefore an interesting strategy to strengthen the immune response during the outbreak of COVID-19, while a vaccine is not developed. Some studies have been shown significant findings in favor of High intensity interval training (HIIT) protocols when compared to moderate intensity exercise, showing how immunological system responds to vigorous to high intensity training. However, HIIT has a lower cost of time, reducing the time/efficiency ratio, that is, a lower cost of time with similar or even better benefits to higher volume exercise programs. Let us not forget: "time is the most precious asset we have".

Background: Physical exercise programs are typically composed of activities directed to the development of different physical abilities, usually stimulated in the same session. Objective: The aim of the study was to determine the effect of one session of aerobic exercise at high intensity to 1% and 10% gradient on the height (HJump) and kinematics of the depth jump (PExc - eccentric, concentric phase PCon, and contact time – CT). Methods: Twenty-five moderately trained men (VO2Max 53.2 ± 4.3 mL.kg-1.min-1) attended five visits in the laboratory. Familiarity with the procedures in depth jump, VO2Max measures and their velocity associated (VVO2Max), and time to exhaustion performance (TLim) were performed at two initial visits. Results: On the three subsequent visits, the volunteers were subjected to three maximum depth jumps before and 10 min after the following conditions: (1) running intervals at high intensity of 10% gradient (R10%), (2) at 1% gradient (R1%), and control condition (CON). The order of conditions was determined randomly. A running condition did not induce significant changes from HJump (R1% 1.1% vs 1.0% R10%) when expressed as percentage difference from the CON condition. The PExc, PCon, and CT also did not change after running sessions (P> 0.05). None of the intervals running strategies were able to generate significant change in height and kinematics of the vertical depth jump. Conclusion: The prescription of the running at VVO2Max in 1% or 10% gradient does not seem to lead to concurrent effect, is suggested to ensure the concomitant development of maximal aerobic power and explosive strength.

Background: For decades the literature has been investigating the ideal dose-response regarding the frequency, intensity and volume of training that optimize the increase in muscle strength and power in athletes and non-athletes. Objective: Evaluate the effects of strength training from a nonlinear (NLP) and non-periodized (NP) model on muscular peak power in soccer players. Methods: Twelve male junior football players from a professional team in Cabo Frio (Brazil) were recruited and randomly divided into two groups (6 in each group). The groups were randomly divided into: G1 - (Body mass: 64.7 ± 6.5 kg; Height: 172.3 ± 5.8 cm; % fat: 5.1 ± 2.7; Age: 17.5 ± 1.0 years) performed RT with NLP model; G2 - (Body mass: 66.1 ± 4.7; Height: 177.1 ± 6.1 cm; % fat: 5.1 ± 1.2, age: 17.6 ± 0.5 years) performed RT with NP model. Both groups are subjected to 12 weeks of training. PNL strength training consisted of weight training sessions on alternate days, 3 times a week, the rest intervals were 120s among the exercises and included 10 exercises. NLP distribution was as follows: Day 1 (3x4-6 maximum repetitions [RM] with rest intervals of 120 sec between sets); Day 2 (3x8-10RM with 60-90 rest intervals between sets); and day 3 (3x12-15RM with rest intervals of 60 sec between sets). NP training performed the same duration, weekly frequency, exercises and number of sets (3 sets 8-10RM and 60-90 sec rest intervals). Before and after NP and NLP training, muscle peak, speed and agility were evaluated. Results: The ANOVA with mixed model showed no significant interaction between group and moment (F(1,10) = 0.133; p=0.72), and no significant main effect for group (F(1,10) = 0.032; p=0.86) in muscular peak power. There was a significant main effect for moment (F(1,10) = 14.872; p=0.003), where were  showed that Post-training presented higher values of muscular peak power compared to Baseline (p= 0.003). Conclusion: It is concluded that both training organization models are effective and can be used to develop peak muscle power.

Background: The inclusion of gymnastic-based movements in workout routines in many exercise training programs, generally called mixed modality training (MMT), and even in many competitions, is increasingly common. In contrast to artistic gymnastic competitions, MMT workouts aim to complete as many movements as quickly as possible, which tends to deform the movement pattern proposed by artistic gymnastics. Execution of the MMT workouts with more of the gymnastics-based style (i.e., based on the gymnastics movement pattern) could improve performance in exercises with a high-level complexity, such as the "ring muscle up" (RMU). Thus, this study aimed to analyze the kinematic aspects of RMU, performed by a former gymnast both with and without the gymnastics based style. Methods: A former gymnast with a successful transition to MMT, carried out RMU using two movement patterns: 1) close to the classical artistic gymnastics pattern ("Front uprise"), and 2) close to that used by many athletes not from gymnastics. The athlete performed RMU, three times with each proposed movement pattern. Images were captured using a high-speed digital camera. Hip and ankle displacement, velocity and acceleration were recorded and analyzed. Results: The execution of RMU was faster and the hip vertical displacement was greater when RMU was carried out with a gymnastics-based style, while ankle displacement path, peak velocity and acceleration were lower. Conclusion: The use of a gymnastics-based style to carry out RMU seems to be advantageous from the biomechanical point of view, favoring the performance of RMU.