ABSTRACT
Cell swelling caused by resistance training is proposed to provide an anabolic stimulus for muscle growth and it is believed that these effects are heightened with the use of low loads. The purpose of this study was to compare the acute effects of two volume-equated resistance training (RT) protocols, low-load (LL) versus high-load (HL), on elbow flexor muscles thickness, arm circumference, and blood lactate concentration in well-trained individuals. Eight resistance-trained males performed the following two RT protocols involving unilateral elbow flexion of the dominant arm: i) LL, four sets with 50% 1 repetition-maximum [1 RM] and ii) HL, ten sets with 85% 1 RM until failure, and equated volume. Pre- and post-session measurements included muscle thickness of the elbow flexors (biceps brachii and brachialis), upper arm circumference, and blood lactate concentration. Significant pre- to post-session increases were found in both protocols for muscle thickness (F (1, 28) = 11.74, p = 0.0019), and blood lactate (F (1, 28) = 35.55, p < 0.0001); no statistically significant differences were observed between conditions, however, the magnitude of increases favored LL. Significant between-condition differences favoring LL were observed for total repetitions (p = 0.007), time under tension (p = 0.007), and training density (p = 0.007). These results suggest that LL training promotes superior post-session increases in muscle thickness, indicating that RT protocols with longer times under tension and densities are beneficial when the goal is to promote acute cell swelling.
ABSTRACT
The purpose of this study was to compare the influence of measuring the overall session rating of perceived exertion (session-RPE) at 10 vs. 30 minutes following exercise. Eight boxers completed three different standardized training sessions of different intensities (easy, moderate and hard) in a matchedpairs, randomized research design. Exercise intensity was assessed during each bout by measuring heart rate, blood lactate concentration and session-RPE. To assess the effect of measurement timing on session-RPE, RPE data were collected either 10 or 30 minutes post-exercise. There was no significant effect of measurement time on session-RPE values following easy (10 minutes: session-RPE = 1.3 ± 1.0 Arbitrary Unit (AU), %Heart Rate Reserve (HRR) = 49.5 ± 11.1, and ∆Blood lactate = -2.3 ± 16.3%; 30 minutes: session-RPE = 1.7 ± 1.0 AU, %HRR = 51.3 ± 10.8, and ∆Blood lactate = 0.7 ± 25.2%), moderate (10 minutes: session-RPE = 2.7 ± 1.6 AU, %HRR = 67.2 ± 10.8, and ∆Blood lactate = 2.2 ± 19%; 30 minutes: session-RPE = 2.5 ± 0.9 AU, %HRR = 67.2 ± 5.9, and ∆Blood lactate = 24.5 ± 17.1%) and hard (10 minutes: session-RPE = 5.7 ± 1.0 AU, %HRR = 88.1 ± 6.3, and ∆Blood lactate = 146.3 ± 87.9%; 30 minutes: session-RPE = 5.8 ± 1.9 AU, %HRR> = 83.3 ± 8.0, and ∆Blood lactate = 91.6 ± 39%) sessions. In conclusion, our findings suggest that session-RPE can be used in boxing training routines across a range of intensities and accurate measurements can be determined as early as 10 minutes after exercise. Key PointsIt is difficult to quantify and monitoring the external training load in martial arts (e.g. Aikido, Kung Fu, Judo) and physical combat sports (e.g. Boxing, Muay Thai), session RPE method appears to be a reliable method to quantifying training load in those sports.For many athletes it is impractical to wait 30 minutes after training session to provide a session-RPE. The present findings show that collecting ses-sion-RPE measures at 10 min following exercise ses-sions of various intensities (i.e. easy, moderate, and hard) provide similar values as if taken 30 min fol-lowing the session.Our data have significant practical benefit and fur-ther support the practical usefulness of session-RPE for measuring internal training load in sport.
ABSTRACT
Recentemente, a prescrição de exercícios aeróbios, bem como sua associação com os de força, têm sido recomendados pelas principais agências normativas de saúde. Sessões agudas ou treinamento crônico promovem respostas no sistema imunológico, podendo acarretar desistência, não continuidade ou queda no desempenho nos programas de exercícios, pela aumentada susceptibilidade às infecções oportunistas, principalmente infecções do trato respiratório superior (ITRS). Assim, o objetivo do estudo foi investigar as modulações decorrentes dos exercícios de força quanto à contagem leucocitária, dano, inflamação, regeneração muscular e susceptibilidade às ITRS. Foi realizada uma revisão de periódicos nacionais e internacionais nos portais científicos da Capes, Scielo, Science Direct e Highwire. Sugere-se que a leucocitose pode ter como função, preparar o organismo para uma possível demanda celular nos músculos, constituindo-se em uma forma do sistema imunológico se antecipar às necessidades de remodelagem tecidual. A infiltração leucocitária nos tecidos danificados apresenta forte relação na ativação das células satélites e queda na força, demonstrando um padrão bi-modal de recuperação. As pequenas flutuações na contagem leucocitária, especificamente nos linfócitos, após os exercícios de força, quando comparadas aos aeróbios, parecem ser respostas agudas com pouco significado clínico, sem relação com aumento nas ITRS.
Recently, endurance exercises prescription as well as its association with strength exercises, has been recommended by main normative health societies. Acute bouts or chronic training, promote responses in immune system, possibly leading to burn out, none continuity or performance decrease in exercise programs, caused by the increased susceptibility of opportunist infections, mainly upper respiratory tract infections (URTI). Thus, the objective of this study was to investigate the modulations originated from strength exercises as leucocyte counting, damage, inflammation, muscular regeneration and susceptibility to URTI. A revision of national and international periodics was carried through scientific halls such as Capes, Scielo, Science Direct and Highwire. It is suggested that leukocytosis may exert a function of preparing the organism for possible cellular demand in muscle, so that it can be a manner by witch immunological system anticipates to tissue remodeling necessities. Leucocyte infiltration in damaged tissues presents a strong bound in satellites cells activation and strength decrease, showing a bi-modal pattern of recovery. The small fluctuations in the leucocytes counting, specifically in the lymphocytes, after strength exercises, when compared with aerobic exercises, seems to be acute responses with little clinical relevance, without relation to the increase in the URTI.