Showing papers by "Cassiano Merussi Neiva published in 2014"

Rating of perceived exertion as a tool for prescribing and self regulating interval training: a pilot study

Abstract: The aim of the present study was to analyse the usefulness of the 6-20 rating of perceived exertion (RPE) scale for prescribing and self-regulating high-intensity interval training (HIT) in young individuals. Eight healthy young subjects (age = 27.5±6.7 years) performed maximal graded exercise testing to determine their maximal and reserve heart rate (HR). Subjects then performed two HIT sessions (20 min on a treadmill) prescribed and regulated by their HR (HR: 1 min at 50% alternated with 1 min at 85% of reserve HR) or RPE (RPE: 1 minute at the 9-11 level (very light-fairly light) alternated with 1 minute at the 15-17 level (hard-very hard)) in random order. HR response and walking/running speed during the 20 min of exercise were compared between sessions.No significant difference between sessions was observed in HR during low- (HR: 135±15 bpm; RPE: 138±20 bpm) and high-intensity intervals (HR: 168±15 bpm; RPE: 170±18 bpm). Walking/running speed during low- (HR: 5.7±1.2 km · h -1 ; RPE: 5.7±1.3 km · h -1 ) and high-intensity intervals (HR: 7.8±1.9 km · h -1 ; RPE: 8.2±1.7 km · h -1 ) was also not different between sessions. No significant differences were observed in HR response and walking/running speed between HIT sessions prescribed and regulated by HR or RPE. This finding suggests that the 6-20 RPE scale may be a useful tool for prescribing and self-regulating HIT in young subjects.

Burnout and playing position: a study of Brazilian soccer players.

Abstract: IntroductionCurrently, there is great concern to provide adequate working conditions not only for the sake of productivity but also for the health, quality of life, and future of workers. Thus, occupational stress, which may have negative effects on health, well-being, and job performance, is a recent topic of study (Maslach & Leiter, 2008; Sarafino, 2008; Taylor, 2009).Maslach and Jackson (1981, p. 99) defined burnout as "a syndrome of emotional exhaustion and cynicism that occurs frequently among individuals who do human service work". When people feel burnt out, they believe that they have exhausted their psychological resources and developed cynical and negative attitudes toward others and a negative view of themselves. Therefore, "workers feel unhappy about themselves and dissatisfied with their accomplishments on the job" (Maslach & Jackson, 1981, p. 99). Furthermore, burnout appears to be correlated "...with various self-reported indices of personal distress, including physical exhaustion, insomnia, increased use of alcohol and drugs, and marital and family problems" (Maslach & Jackson, 1981, p. 100).Burnout characteristics in athletes are similar to those experienced by professionals who work in direct and frequent contact with other people and involve the perception that personal resources are insufficient or inadequate to cope with stress. As a result, people develop negative attitudes, behaviors, and feelings that lead to practical and emotional problems in the workplace. Many authors consider the several reports of elite athletes who abandon their sport at the peak of their careers to be examples of the effects of the excessive stress in sports (Arce, Francisco, Andrade, Arce & Raedeke, 2010; Hill & Appleton, 2011; Ivarsson, 2008; Raedeke, 1997; Lemyre, Roberts & Stray-Gundersen, 2007; Lemyre, Hall & Roberts, 2008).Burnout in sports is primarily considered to be a response to chronic stress characterized by performance decreases, sport devaluation, and physical and emotional exhaustion. Media reports of the "negative sport experiences of a series of high-profile athletes" (Cresswell & Eklund, 2006a, p. 219) have stimulated research interest in this subject. In turn, these researchers have proposed that the negative experiences of these athletes are similar to the burnout in other professions (Cresswell & Eklund, 2006a; 2006b).Professional exhaustion in athletes has three key aspects: 1) emotional and physical exhaustion due to the excessive demands imposed by training sessions and competition; 2) a reduced sense of self-realization accompanied by the perception that objectives are unattainable; and 3) devaluation and a lack of interest in the sport (Raedeke, 1997; Lemyre, Hall & Roberts, 2008; Gustafsson, Hassmen, Kentta & Johansson, 2008).With regard to the three burnout subscales (emotional exhaustion, depersonalization, and dissatisfaction with one's performance), depersonalization appears to be least applicable to athletes due to the contextual differences between sports and the service industry. Given that depersonalization assesses devaluation and indifference toward one's career, it may measure the development of negative attitudes towards sports involvement in athletes (Raedeke, 1997).Although the relationship between athletes and coaches is important, it does not seem to be the determining factor for burnout. Therefore, sports burnout must be defined in terms of the key element of their jobs: performance (Raedeke, 1997). Professional exhaustion in athletes may be due to training and competition demands as well as associated with the perception of poor performance regarding skills and achievements (Hill & Appleton, 2011; Kimberley, Bartholomew, Ntoumanis, Ryan, Jos, Bosch & Thogersen-Ntoumani, 2011; Raedeke, 1997). However, social support seems to be an important factor in protecting athletes from burnout (Cresswell, 2009). …

Estudo do comportamento cortisol, gh e insulina apos uma sessao de exercicio resistido agudo

Abstract: INTRODUCAO: Muitos trabalhos tem estudado o comportamento hormonal nos exercicio resistido, entretanto poucos relacionam os hormonios cortisol, GH e insulina. OBJETIVO: Estudar os ajustes das concentracoes plasmaticas dos hormonios cortisol, GH e insulina em exercicios resistidos de mesma intensidade com relacao a massas musculares distintas. METODOS: Dez voluntarios, com 20,3 ± 4,2 anos, 74,1 ± 10,2 kg de peso, 177,2 ± 4,6 cm de estatura e 23,8 ± 3,2 kg/m2 de IMC, realizaram uma sessao de leg press (LP) e supino reto (SR) com quatro series com 10 repeticoes a 70% 1 RM com tres minutos de intervalo. Foram coletadas amostras de sangue para dosagem das concentracoes plasmaticas de cortisol, GH e insulina em repouso (Pre) e em 0' (Rec. 0'), 30' (Rec. 30') e 90' (Rec. 90') de recuperacao. RESULTADOS: As concentracoes plasmaticas de cortisol foram significativamente reduzidas ao final da recuperacao em LP (2,20±0,37 ng/dl para 1,33±0,38ng/dl) em relacao a pre-dosagem. As concentracoes de GH e insulina elevaram-se significativamente durante a recuperacao. GH em LP foi significativamente maior em Rec. 0' (2,75±3,29 ng/ml para 9,60±5,32 ng/dl) do que em pre. A insulina elevou-se significativamente em Rec. 30' em LP (14,70±7,92 ulU/ml para 21,66 ± 8,61 ulU/ml) e em SR (6,17 ± 2,99 ulU/ml para 19,70 ± 13,8 ulU/ml) em relacao a pre. As concentracoes plasmaticas de insulina pre em LP foram significativamente superiores a SR (14,70 ulU/ml e 6,17 ± 2,99 ulU/ml). CONCLUSAO: O exercicio resistido promoveu diferentes ajustes nas concentracoes hormonais de cortisol, GH e insulina durante o periodo de recuperacao.