The effects of detraining and retraining periods on fat-mass and fat-free mass in elite male soccer players

Abstract

The aim of the study was to examine the effects of a detraining period (DTP) (i.e., off-season) with an individually prescribed training program, and a retraining period (RTP) (i.e., pre-season) combining soccer and flywheel-based strength training on fat-free mass (FFM) and fat-mass (FM) in 10 elite professional male soccer players. The present study used a controlled repeated-measures research design to investigate the changes in FFM and FM using dual-energy X-ray absorptiometry. Whole body %FM increased (effect size (ES) = 0.87 ± 0.46) and FFM reduced after DTP (ES = −0.30 ± 0.19), returning to values comparable to the end of the previous season after RTP. At regional levels, arms, legs, and trunk %FM increased (ES = from 0.42 to 1.29) while trunk-FFM was reduced (ES = −0.40 ± 0.26) after DTP, returning to the values observed at the end of the previous season after RTP. Legs-FFM did not change after DTP, with a substantial increase after RTP in comparison with pre-season values (ES = 0.34 ± 0.29 and 0.53 ± 0.36 for the right and left leg, respectively). Despite the small sample size of the present study, the findings indicate that elite soccer players can be allowed 2 weeks of rest during a five-week DTP, since the changes in %FM and FFM were relatively small, and FM and FFM returned to the optimal initial values for competition after the proposed RTP during the pre-season.

Dual Careers of Athletes During COVID-19 Lockdown

“…It is possible to speculate that these conditions resemble or even exacerbate off-training physical behaviors of athletes (Sperlich and Holmberg, 2017 ; Izzicupo et al, 2019 ). Studies on vascular, metabolic, and muscular adaptations to unloading (e.g., uninterrupted sitting and bed rest) as well as on post-injury conditions (Milsom et al, 2014 ) or the detrimental effects of the off-season (Suarez-Arrones et al, 2019 ) allow some speculations. Findings indicate that prolonged and uninterrupted sitting is associated with body fatness in highly trained athletes (Júdice et al, 2014 ); acute lower limbs dysfunction in healthy young subjects (Padilla and Fadel, 2017 ); increased sympathetic and renin–angiotensin system activity (Young and Leicht, 2011 ), plasma fibrinogen (Izzicupo et al, 2020 ), hematocrit, hemoglobin, and red blood cell count and a reduction in plasma volume (Howard et al, 2013 ); modified glucose and lipid metabolisms (Bergouignan et al, 2009 ; Stephens et al, 2011 ); changes in muscle size and architecture and tendon mechanical properties (De Boer et al, 2007 ; de Boer et al, 2008 ); muscle loss (Miles et al, 2005 ); and reductions in muscle strength, power, and rate of force development (Mujika and Padilla, 2001 ; De Boer et al, 2007 ; Bosquet et al, 2013 ; Rejc et al, 2018 ).…”

UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research

“…There are different time points throughout the season where players may need to manipulate their intake to illicit changes in fat mass (FM) or skeletal muscle mass (fat free soft tissue mass (FFSTM)). 156 This may occur during preseason or during injury where nutrient intake may need to be altered to the needs of physical output. 157 This relationship is very important to the athlete's health and performance as it is often not reflected in BM measurement alone.…”

Inertial flywheel knee- and hip-dominant hamstring strength exercises in professional soccer players: Muscle use and velocity-based (mechanical) eccentric overload

“…The magnitude of this overload is largely dependent on previous experience with this technology as was shown by Tous-Fajardo et al [ 25 ], and the experience with these devices is crucial to optimize training. Previous studies using flywheel technology have shown benefits such us improved performance [ 24 , 28 , 29 ], chronic adaptations on muscular strength, power and gains in lean mass [ 28 – 30 ], higher force and power production combined with low energy expenditure [ 28 ] or reduced hamstring injuries in professional soccer players [ 11 , 22 , 28 ]. It should be noted that with the use of this flywheel technology a familiarization process is required and there is a lack of standard procedures for exercise loading prescription and limited evidence with elite athletes [ 28 ].…”