Associations between wellness and internal and external load variables in two intermittent small-sided soccer games

The purpose of this study was to test the associations between wellness and internal and external load variables during two intermittent small-sided games (SSGs). Ten male amateur soccer players (age: 19.8±1.6 years; experience: 8.3±2.1 years; height: 177.4±3.8 cm; weight: 71.7±4.2 kg) voluntarily participated in this study. The 5 × 5 format was played in 3 × 6 min and 6 × 3 min regimens. Muscle soreness (DOMS), stress, fatigue, and sleep quality were rated before each session. Perceived exertion (RPE); mean heart rate (HRmean); total (TD), jogging (JD), running (RD), and sprinting (SD) distances; player's training load (PTL); and total accelerations (TAc) were monitored during SSGs. In the case of the 3 × 6′ regimen, large negative correlations between DOMS and TD (−0.68, [−0.89; −0.20]), JD (−0.66, [−0.89; −0.17]) and SD (−0.63, [−0.88; −0.12]) were found, and very large negative correlations between DOMS and PTL (−0.84, [−0.95; −0.53]) were found. Very large (−0.73, [−0.91; −0.30] and large (−0.61, [−0.87; −0.09]) negative correlations between DOMS and HRmean and PTL, respectively, were observed during the 6 × 3′ regimen. Regarding the associations between load variables, during the 6 × 3′ regimen, RPE was very largely correlated with TD (0.77, [0.37; 0.93]), JD (0.70, [0.25; 0.90]) and largely correlated with TAc (0.67, [0.19; 0.89]). In the 3 × 6′ regimen, large correlations were found between RPE and SD (0.62, [0.10; 0.87]) and TAc (0.61, [0.09; 0.87]). Overall, PTL was nearly perfectly correlated with TD (0.96, [0.86; 0.99]) and JD (0.94, [0.81; 0.98]), very largely correlated with TAc (0.87, [0.61; 0.96]), and largely correlated with RD (0.72, [0.29; 0.91]). The results of this study suggest that wellness status may influence workload in SSGs; in particular, DOMS may be moderately-to-largely detrimental to both internal and external load variables. Moreover, it was confirmed that RPE is moderately-to-largely correlated to objectively measured external load variables.