“…A total of 20 studies involved speed tests: three of them used a 20 m sprint test ( 42 , 50 , 57 ); one used a 20 m speed test ( 33 ); four used a 10 m sprint test ( 37 , 42 , 48 , 50 ); one used a repeated sprint ability test ( 37 ); three used a 10 m dash test ( 38 , 49 , 59 ); two used a 40 m dash ( 38 , 49 ); two used a 10 m speed test ( 39 , 41 ); three used a 30 m speed test ( 39 , 41 , 51 ); one used a 35 m repeated sprint test ( 40 ); four used a 30 m sprint test ( 45 , 46 , 53 , 54 ); one used a 30 m dash ( 59 ); one used a 100 m test ( 54 ); one used a 20 m starting run ( 55 ); and one study used a 40 m speed test ( 58 ). The participants in these studies included university students ( 33 , 55 ), high school students ( 50 ), professional female participants ( 37 ), amateur participants ( 41 , 42 , 46 , 52 ), semi-professional participants ( 59 ), junior participants ( 49 ), elite participants ( 48 , 57 ), and secondary school participants ( 51 ); six studies did not report the level of participants ( 38 – 40 , 45 , 54 , 58 ). Most studies showed a significant increase in speed performance after core training interventions.…”