. 2019 Feb 12;7(2):2325967118825469. doi: 10.1177/2325967118825469

TABLE 1.

Summary of Included Studies

Study	Year	n	Level	Ball Weight^a	Training Duration	Velocity Change, mph
Logan²⁶	1966	19	College	2.5-5.5 lb (pulley)	4 wk	+9.28
Brose⁵	1967	21	College	10-lb pulley, 10-oz ball	6 wk	No significant difference reported^b
Straub³⁷	1968	48	High school	7-17 oz, incremental	6 wk	No significant difference reported^b
Litwhiler²⁵	1973	5	College	7-12 oz, incremental	12 wk	+11.2
DeRenne⁸	1990	30	High school	4-6 oz, incremental	10 wk	Underweight, +4.72; overweight, +3.75
DeRenne⁷	1994	225	High school and college	4 or 6 oz	10 wk	+5 (approximate)^c
Szymanski³⁸	2011	21	High school	7 oz	8 wk	No significant difference reported^b
Yang⁴⁶	2013	24	High school	4.4 oz	10 wk	+2.1
Reinold³³	2018	38	High school	2-32 oz, incremental	6 wk	+2.2
Warm-up with weighted ball
Straub³⁷	1968	60	High school	10 and 15 oz	20 pitches	No significant difference reported^b
Morimoto³⁰	2003	8	College	4.5 and 5.5 oz	6 or 18 pitches	+3 (approximate)^c

^aA regulation baseball weighs 5 oz.

^bThe authors did not report quantitative velocity data.

^cApproximate values are used when only graphical presentations of the outcome measure were available in the report.