Twenty-four-hour rhythms of muscle strength with a consideration of some methodological problems

Effects of time-of-day on neuromuscular function in untrained men: Specific responses of high morning performers and high evening performers

“…The present study was designed to investigate the effects of the time of day on the neuromuscular performance of thigh muscles and possible mechanisms behind the inter-individual differences in the diurnal fluctuations in strength performance. In the total group of participants, so far the largest experiment sample in this area of research, our results were consistent with the previous studies with smaller sample sizes investigating knee extensor muscles (Araujo et al, 2011;Callard et al, 2000;Deschenes et al, 1998;Guette et al, 2005a;Nicolas et al, 2005;Onambele-Pearson & Pearson, 2007;Racinais et al, 2005;Sedliak et al, 2008;Sedliak et al, 2011;Teo et al, 2011), since maximal force was significantly greater (~4%) in the evening compared to the morning. The uniqueness of the present study including a large group of participants, however, Diurnal rhythms in maximal strength performance lays in the fact that the high morning performance and high evening performance types were separated from the neutral types and compared with each other.…”

“…It has been previously shown that the sleep deprivation might temporally change performance patterns, however, Bambaeichi et al (2004) found that the diurnal fluctuations in muscle strength did not change after partial sleep loss. Moreover, the time awake (associated with fatigue) and sleepiness has been shown to influence the time-of-dayspecific performance (Araujo et al, 2011;Carrier and Monk., 2000;Edwards et al, 2007), as performance efficiency on a specific task may decrease over the day because of the amount of hours since awakening (Carrier and Monk, 2000).…”

“…The ability to generate force depends on both peripheral and central mechanisms. Peripheral mechanisms include muscle contractility and metabolism, morphology of muscle fibers and local muscle temperature (Araujo et al, 2011;Edwards et al, 2013;Reilly and Waterhouse, 2009).…”

Morphological, molecular and hormonal adaptations to early morning versus afternoon resistance training

“…In a person unaccustomed to morning exercise, voluntary and artificially evoked muscle strength (maximum and explosive),has been repeatedly reported to be on average 5-10% lower in the morning hours compared to the rest of the day (e.g., Araujo et al, 2011, Callard et al, 2000, Castaingts et al, 2004, Coldwells et al, 1994, Deschenes et al, 1998, Gauthier et al, 1996, Giacomoni et al, 2005, Guette et al, 2005a, Mora-Rodrıguez et al, 2012, Nicolas et al 2005., Sedliak et al, 2008. This phenomenon has been termed as "morning neuromuscular deficit" due to the fact that that inputs from the central nervous system are, at least partly, an important source (for a review see Sedliak 2013).…”

Does Lowering Evening Rectal Temperature to Morning Levels Offset the Diurnal Variation in Muscle Force Production?

“…The observation of a significant diurnal or circadian rhythm seems to be somewhat dependent on factors such as time on task, motivation of subjects to perform, and their familiarity with the tasks to be performed Giacomoni et al, 2005). The exact mechanisms for this observed diurnal variation in muscle performance are as yet unknown but have been attributed to peripheral or muscle-related variables (contractibility, metabolism, and morphology of muscle fibers and local muscle temperature), which can be influenced by hormonal and ionic muscle process variations (Araujo et al, 2011;Bambaeichi et al, 2005;Reilly & Waterhouse, 2009;Tamm et al, 2009), and/or central/neurological factors (central nervous system command, alertness, motivation, and mood; Castaingts et al, 2004;Giacomoni et al, 2005;Racinais et al, 2005;Racinais, 2010). Input from the body clock and proteins and peripheral clocks-that is, an endogenous component to the daily variation in muscle force production-has been suggested to be important, although evidence relating to this is limited (Sargent et al, 2010;Zhang et al, 2009).…”