A research project assessed the effects of a 10-week hiatus from resistance training on peak strength and muscle growth. The findings revealed that taking a break after 10 weeks in a 20-week strength training program had minimal impact on muscle development. Interestingly, strength levels were more effectively maintained during the break than muscle volume.
A research project carried out at the University of Jyväskylä’s Faculty of Sport and Health Sciences examined how a 10-week pause in resistance training influenced peak strength and muscle growth. The results indicated that a 10-week hiatus, occurring halfway through a 20-week training regimen, had little effect on overall development. Notably, strength was maintained more effectively than muscle mass during this period.
The study analyzed the outcomes of 20 weeks of resistance training comparing two groups: one group continued training without interruption, while the other group took a 10-week break at the halfway point.
The findings showed that both groups experienced similar advancements in maximum strength and muscle size development. Researchers attributed this comparable progress to the fact that both strength and muscle size quickly reverted to pre-break levels once training resumed.
“In the weeks following the break, progress was initially rapid, and just five weeks into retraining, participants had already returned to their pre-break performance levels,” states Eeli Halonen from the Faculty of Sport and Health Sciences, who is working on his doctoral dissertation regarding the effects of training interruptions.
“Progress for those who trained continuously for 20 weeks clearly slowed down after the first ten weeks,” Halonen further explains. “As a result, there was ultimately no discrepancy in muscle size or strength growth between the two groups.”
“Muscle memory” will be further explored at the cellular and molecular levels
The phenomenon that allows for a swift return to previous muscle size following a break is referred to as “muscle memory.”
“The physiological mechanisms that underlie muscle memory are not completely understood,” senior researchers Juha Hulmi and Juha Ahtiainen say, “and our next goal is to investigate the cellular and molecular changes in muscles that may explain this phenomenon more thoroughly.”
Peak strength is more effectively maintained than muscle volume
The study also discovered that peak strength was retained better during the break compared to muscle size.
“This could possibly be attributed to the idea that changes within the nervous system tend to be more permanent than the external changes in muscle,” Halonen explains.
According to this study and prior evidence, it appears that those who frequent the gym need not be overly concerned about taking breaks of up to ten weeks, provided their training remains consistent and progressive throughout the remainder of the year.
However, it’s important to note that participants who paused their training achieved similar results in 30 weeks as those who maintained continuous training for 20 weeks.
“While the break does slow down progress to some extent,” Halonen observes, “it’s reassuring to know that regaining pre-break levels can occur surprisingly quickly.”
This study was conducted at the Faculty of Sport and Health Sciences at the University of Jyväskylä, involving young Finnish men and women who were active but lacked prior experience in systematic resistance training.
The findings were published in the Scandinavian Journal of Medicine & Science in Sports. The research was supported by the Rehabilitation Foundation Peurunka, the Finnish Sports Research Foundation, the Academy of Finland, and the Faculty of Sport and Health Sciences at the University of Jyväskylä.
