Background: Exercise leads to a robust inflammatory response mainly characterized by the mobilization of leukocytes and an increase in circulating inflammatory mediators produced by immune cells and directly from the active muscle tissue. Both positive and negative effects on immune function and susceptibility to minor illness have been observed following different training protocols. While engaging in moderate activity may enhance immune function above sedentary levels, excessive amounts of prolonged, high-intensity exercise may impair immune function. Thus, the aim of the present review was to clarify the inflammatory effects in response to different exercise intensities. Methods: Search was performed on PubMed and was completed on July 31st, 2017. The studies were eligible if they met the predefined inclusion criteria: a) observational or interventional studies, b) conducted in healthy adults (18-65 years), c) written in Portuguese, English or Spanish, d) including moderate and/or intense exercise. Eighteen articles were included. The specific components that were examined included circulating blood levels of cytokines, leukocytes, creatine kinase (CK) and C-reactive protein (CRP). The methodological quality of the included studies was assessed. Results: Most of the intervention studies showed changes in the assessed biomarkers, although these changes were not consistent. White blood cells (WBC) had an increase immediately after intensive exercise (> 64% VO 2max), without alteration after moderate exercise (46-64% VO 2max). The results suggested an elevation of the pro-inflammatory cytokines, namely IL-6, followed by an elevation of IL-10 that were more evident after intense exercise bouts. CRP increased both after intense and moderate exercise, with peak increases up to 28 h. CK increased only after intensive and long exercising. Conclusion: In summary, intense long exercise can lead, in general, to higher levels of inflammatory mediators, and thus might increase the risk of injury and chronic inflammation. In contrast, moderate exercise or vigorous exercise with appropriate resting periods can achieve maximum benefit.

Objective: Motivation seems to be a fundamental indicator of long-term physical exercise adherence. Self-Determination Theory (SDT) argues that social environment plays a central role in the satisfaction of basic psychological needs, which might directly affect the quality of one's motivation. Individuals who appear to be more self-determined tend to persist longer at certain behaviors. Therefore, this body of work intends to analyze the relationship between motivational variables and behavioral outcomes in the exercise context, having as theoretical background the Self-Determination Theory.Methods: This systematic review was conducted through an electronic search on Web of Science, PubMed, SPORTDiscus, and PsycINFO. Data such as instruments, main predictors and results were collected from studies published between 1985 and 2018. A total of 35 empirical studies were considered for a detailed analysis.Results: Results showed the relevance of autonomy support performed by exercise professionals, as well as the major contribution that these behaviors have toward the satisfaction of basic psychological needs, besides the inherent benefits of developing more autonomous regulations. According to the literature, few studies have analyzed interpersonal thwarting behavior and the way this relates to basic psychological needs' frustration. Nether less, there seems to be a negative relationship between less self-determined regulations and exercise practice.Conclusion: Despite the existence of numerous cross-sectional studies that demonstrate positive correlations between SDT and behavioral outcomes in the exercise context, longitudinal research that analyzes all six dimensions of interpersonal behaviors and their relationship with persistence and adherence to exercise proves to be crucial. However, according to this review, interventions based on SDT appear to be fundamental when it comes to promote the maintenance of a long-term exercise practice.

Objective The present study aimed to examine the bright and dark sides of motivation, based on self‐determination theory, as predictors of enjoyment, intention to continue exercising, and exercise persistence. In addition, we analyzed the mediation role of each variable and tested the model invariance between male and female exercisers. Methods A total of 575 gym exercisers (female = 230) aged between 18 and 65 years (M = 34.07; SD = 11.47) participated in this study. All participants had at least 6 months of regular exercise practice; exercise frequency of the participants ranged from 2 to 7 sessions per week (M = 3.52; SD = 1.28) and training sessions lasted approximately 30 and 120 minutes (M = 61.54; SD = 17.64). Participants completed a multisection questionnaire assessing interpersonal behaviors, basic psychological needs satisfaction and frustration, behavioral regulations, enjoyment, and intentions to continue exercising. Exercise persistence was assessed 6 months after initial assessment using gym computer system attendance records. Several analyses, namely, confirmatory factor analysis, structural equation modeling, serial mediation analysis, and structural invariance testing, were performed to increase theoretical and empirical knowledge. Results Positive associations were observed among the bright side of motivation, enjoyment, intention to continue exercising, and persistence. On the other hand, the dark side of motivation was negatively associated with the bright side constructs, enjoyment, intention, and exercise persistence. Both measurement [χ2(370) = 1496.708, χ2/df = 4.05; B‐S P < .001, CFI = 0.907, TLI = 0.901, SRMR = 0.056, RMSEA = 0.073 (CI 90% = 0.063, 0.083)] and structural models [χ2(393) = 2484.994, χ2/df = 6.323; B‐S P < .001, CFI = 0.908, TLI = 0.900, SRMR = 0.075, RMSEA = 0.071 (CI 90% = 0.067, 0.075)] displayed acceptable fit to the data. The results also showed that basic psychological needs satisfaction, autonomous motivation, enjoyment, and intention to continue exercising were significant mediators. However, enjoyment had the highest effect on exercise persistence. In addition, structural model invariance was confirmed between male and female exercisers. Conclusion Motivational determinants have implications for predicting emotional, cognitive, and behavior‐related outcomes. Individuals should perceive exercise instructors as supportive and exercising as a fun activity to endorse long‐term exercise persistence.

Applying properly structured strategies in the warm-up and avoiding a long rest in the post-warm-up improves explosive performance. Studies tend to recommend a short active warm-up strategy (10-15 min), gradually increasing intensity (~ 50-90% of maximum heart rate), and the use of heated garments soon after the warm-up to maintain muscle temperature. However, 2 min of active re-warm-up with short-term sprints and jumps should be needed for transitions longer than 15 min (~ 90% of maximum heart rate). Last, at the half-time re-warm-up, combining heated garments to maintain muscle temperature and performing an active strategy, with explosive tasks or small-sided games for 5 min before re-entering the game, resulted in better explosive performance than 15 min of resting.

Warm-up before physical activity is commonly accepted to be fundamental, and any priming practices are usually thought to optimize performance. However, specifically in swimming, studies on the effects of warm-up are scarce, which may be due to the swimming pool environment, which has a high temperature and humidity, and to the complexity of warm-up procedures. The purpose of this study is to review and summarize the different studies on how warming up affects swimming performance, and to develop recommendations for improving the efficiency of warm-up before competition. Most of the main proposed effects of warm-up, such as elevated core and muscular temperatures, increased blood flow and oxygen delivery to muscle cells and higher efficiency of muscle contractions, support the hypothesis that warm-up enhances performance. However, while many researchers have reported improvements in performance after warm-up, others have found no benefits to warm-up. This lack of consensus emphasizes the need to evaluate the real effects of warm-up and optimize its design. Little is known about the effectiveness of warm-up in competitive swimming, and the variety of warm-up methods and swimming events studied makes it difficult to compare the published conclusions about the role of warm-up in swimming. Recent findings have shown that warm-up has a positive effect on the swimmer's performance, especially for distances greater than 200 m. We recommend that swimmers warm-up for a relatively moderate distance (between 1,000 and 1,500 m) with a proper intensity (a brief approach to race pace velocity) and recovery time sufficient to prevent the early onset of fatigue and to allow the restoration of energy reserves (8-20 min).

The main aim of the present study was to analyze the relationships between dry land strength and power measurements with swimming performance. Ten male national level swimmers (age: 14.9 ± 0.74 years, body mass: 60.0 ± 6.26 kg, height: 171.9 ± 6.26, 100 m long course front crawl performance: 59.9 ± 1.87 s) volunteered as subjects. Height and Work were estimated for CMJ. Mean power in the propulsive phase was assessed for squat, bench press (concentric phase) and lat pull down back. Mean force production was evaluated through 30 s maximal effort tethered swimming in front crawl using whole body, arms only and legs only. Swimming velocity was calculated from a maximal bout of 50 m front crawl. Height of CMJ did not correlate with any of the studied variables. There were positive and moderate-strong associations between the work during CMJ and mean propulsive power in squat with tethered forces during whole body and legs only swimming. Mean propulsive power of bench press and lat pull down presented positive and moderate-strong relationships with mean force production in whole body and arms only. Swimming performance is related with mean power of lat pull down back. So, lat pull down back is the most related dry land test with swimming performance; bench press with force production in water arms only; and work during CMJ with tethered forces legs only.

The relative contribution of arm stroke and leg kicking to maximal fully tethered front crawl swimming performance remains to be solved. Twenty-three national level young swimmers (12 male and 11 female) randomly performed 3 bouts of 30 s fully tethered swimming (using the whole body, only the arm stroke, and only the leg kicking). A load-cell system permitted the continuous measurement of the exerted forces, and swimming velocity was calculated from the time taken to complete a 50 m front crawl swim. As expected, with no restrictions swimmers were able to exert higher forces than that using only their arm stroke or leg kicking. Estimated relative contributions of arm stroke and leg kicking were 70.3% versus 29.7% for males and 66.6% versus 33.4% for females, with 15.6% and 13.1% force deficits, respectively. To obtain higher velocities, male swimmers are highly dependent on the maximum forces they can exert with the arm stroke (r = 0.77, P < 0.01), whereas female swimmers swimming velocity is more related to whole-body mean forces (r = 0.81, P < 0.01). The obtained results point that leg kicking plays an important role over short duration high intensity bouts and that the used methodology may be useful to identify strength and/or coordination flaws.

The aim of this study was to compare the effect of 3 different warm-up (WU) volumes on 100-m swimming performance. Eleven male swimmers at the national level completed 3 time trials of 100-m freestyle on separate days and after a standard WU, a short WU (SWU), or a long WU (LWU) in a randomized sequence. All of them replicated some usual sets and drills, and the WU totaled 1,200 m, the SWU totaled 600 m, and the LWU totaled 1,800 m. The swimmers were faster after the WU (59.29 seconds; confidence interval [CI] 95%, 57.98-60.61) and after the SWU (59.38 seconds; CI 95%, 57.92-60.84) compared with the LWU (60.18 seconds; CI 95%, 58.53-61.83). The second 50-m lap after the WU was performed with a higher stroke length (effect size [ES] = 0.77), stroke index (ES = 1.26), and propelling efficiency (ES = 0.78) than that after the SWU. Both WU and SWU resulted in higher pretrial values of blood lactate concentrations [La] compared with LWU (ES = 1.58 and 0.74, respectively), and the testosterone:cortisol levels were increased in WU compared with LWU (ES = 0.86). In addition, the trial after WU caused higher [La] (ES ≥ 0.68) and testosterone:cortisol values compared with the LWU (ES = 0.93). These results suggest that an LWU could impair 100-m freestyle performance. The swimmers showed higher efficiency during the race after a 1200-m WU, suggesting a favorable situation. It highlighted the importance of the [La] and hormonal responses to each particular WU, possibly influencing performance and biomechanical responses during a 100-m race.