Irisin in Blood Increases Transiently after Single Sessions of Intense Endurance Exercise and Heavy Strength Training

Abstract

PurposeIrisin is a recently identified exercise-induced hormone that increases energy expenditure, at least in rodents. The main purpose of this study was to test the hypothesis that Irisin increases acutely in blood after singular sessions of intense endurance exercise (END) and heavy strength training (STR). Secondary, we wanted to explore the relationship between body composition and exercise-induced effects on irisin, and the effect of END and STR on muscular expression of the irisin gene FNDC5.MethodsNine moderately trained healthy subjects performed three test days using a randomized and standardized crossover design: one day with 60 minutes of END, one day with 60 minutes of STR, and one day without exercise (CON). Venous blood was sampled over a period of 24h on the exercise days.ResultsBoth END and STR led to transient increases in irisin concentrations in blood, peaking immediately after END and one hour after STR, before gradually returning to baseline. Irisin responses to STR, but not END, showed a consistently strong negative correlation with proportions of lean body mass. Neither END nor STR affected expression of FNDC5, measured 4h after training sessions, though both protocols led to pronounced increases in PGC-1α expression, which is involved in transcriptional control of FNDC5.ConclusionThe results strongly suggest that single sessions of intense endurance exercise and heavy strength training lead to transient increases in irisin concentrations in blood. This was not accompanied by increased FNDC5 expression, measured 4h post-exercise. The results suggest that irisin responses to resistance exercise are higher in individuals with lower proportions of lean body mass.

Increased FNDC5 is associated with insulin resistance in high fat-fed mice

“…2014; Nygaard et al. 2015). In order to ameliorate the acute effects of exercise, mice in the current study were removed from exercise wheels 24 h before sacrifice.…”

“…2014; Nygaard et al. 2015). This increased energy expenditure is proposed to be mediated by increased browning of WAT via increased UCP1 levels (Bostrom et al.…”

Time-Dependent Changes in Increased Levels of Plasma Irisin and Muscle PGC-1<i>α</i> and FNDC5 after Exercise in Mice

“…Acute exercise has been shown to enhance the secretion of irisin in both mice Liu et al 2015) and humans (Löffler et al 2015;Nygaard et al 2015). The secretion of irisin reached a peak and then returned to baseline levels (Norheim et al 2014;Kraemer et al 2014).…”

Actualizaciones Sobre "Irisina" La Nueva Mioquina

“…2015, demostraron que una sola sesión de ejercicio podría aumentar las concentraciones de Irisina circulante, y por lo mismo evaluar la respuesta aguda de un ejercicio de resistencia de tipo interválico de alta intensidad y de un ejercicio de fuerza intenso. Lo que se determinó fue que en ambos protocolos de ejercicio la concentración de Irisina en sangre aumentó (60). Estos hallazgos confirman lo planteado por otros autores que postulan que la Irisina es una mioquina inducida por el ejercicio y que su aumento es transitorio (61,62).…”