Table 6. Risk of bias in randomized controlled trials. Study Randomization process Deviations from intended interventions Missing outcome data Measurement of outcome Selection of reported result Overall RoB (Abat et al., 2016) Low risk Some concerns Low risk Some concerns Some concerns Some concerns (Bahr et al., 2006) Low risk Some concerns Low risk Some concerns Some concerns Some concerns (Demir Benli et al., 2022) Low risk Some concerns Low risk Some concerns Some concerns Some concerns (Beyer et al., 2015) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Biernat et al., 2014) High risk Some concerns Low risk Some concerns Some concerns High risk (Breda et al., 2021) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Cannell et al., 2001) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Cunha et al., 2012) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Frohm et al., 2007) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Habets et al., 2021) Some concerns Some concerns Low risk Some concerns Low risk Some concerns (Jonsson and Alfredson, 2005) Some concerns Some concerns High risk Some concerns Some concerns High risk (Knež and Hudetz, 2023) Low risk Some concerns Low risk Some concerns Some concerns Some concerns (Knobloch et al., 2007) Some concerns Some concerns High risk Some concerns Some concerns High risk (Knobloch et al., 2008) Low risk Some concerns Some concerns Some concerns Some concerns Some concerns (Kongsgaard et al., 2009) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Langberg et al., 2007) High risk Some concerns Low risk Some concerns Some concerns High risk (Lee et al., 2020) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Malliaras et al., 2013) Low risk Low risk Low risk Low risk Low risk Low risk (Niering and Muehlbauer, 2023) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Radovanović et al., 2022) Some concerns Some concerns Low risk Low risk Low risk Some concerns (Rompe et al., 2007) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Rompe et al., 2009) Low risk Some concerns Low risk Some concerns Low risk Some concerns (Ruffino et al., 2021) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Stergioulas et al., 2008) Low risk Some concerns Some concerns Low risk Some concerns Some concerns (van Ark et al., 2016) Low risk Some concerns Some concerns Some concerns Some concerns Some concerns (Verma et al., 2022) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns (Visnes et al., 2005) Low risk Some concerns Some concerns Some concerns Some concerns Some concerns (Young et al., 2005) Some concerns Some concerns Low risk Some concerns Some concerns Some concerns