Table 3. Alterations after 12 weeks of Functional Training (FT, n=16), Traditional Training (TT, n=14) and Control Group (CG, n=15) in the maximum isometric strength, rate of force development and endurance of trunk muscles. Values presented as means and standard deviations.

	Pre-test	Post-test	Δ (%)	ES	Main Effect (group)	Main Effect (time)	Interactions (time x group)	Contrast of adjusted mean values
Trunk Flexors Force (N)
FT	229.85 ± 58.9	281.14 ± 65.0	22%	0.87	p=0.855	p=0.045	p=0.566	p=0.002 *
TT	235.15 ± 84.4	261.36 ± 93.8	11%	0.31				p=0.108
CG	239.19 ± 59.01	252.15 ± 68.18	5%	0.22				p=0.361
Flexors’ RFD (N/s)
FT	16.0 ± 7.4	29.45 ± 17.21	84%	1.81	p=0.994	p=0.001	p=0.415	p=0.001 *
TT	18.65 ± 11.55	26.39 ±15.0	42%	0.67				p=0.033 *
CG	20.22 ± 8.77	25.51 ± 12.7	26%	0.60				p=0.09
Flexors’ Endurance (s)
FT	72.37 ± 66.94	86.18 ± 69.5	19%	0.21	p=0.294	p=0.621	p=0.221	p=0.001 *
TT	90.28 ± 81.61	100.07 ± 83.67	11%	0.12				p=0.008 *
CG	53.3 ± 46.4	57.73 ± 50.65	9%	0.10				p=0.127
Trunk Extensors Force (N)
FT	262.8 ± 72.0	306.55 ± 78.56	17%	0.61	p=0.401	p=0.135	p=0.426	p=0.003 *
TT	258.32 ± 97.1	288.10 ± 76.4	12%	0.31				p=0.059
CG	261.28 ± 61.46	257.1 ± 58.8	-1%	-0.06				p=0.788
Extensors’ RFD (N/s)
FT	24.58 ±10.4	28.59 ± 9.6	16%	0.40	p=0.023	p=0.169	p=0.665	p=0.050 *
TT	25.96 ± 9.0	30.44 ± 14.7	17%	0.49				p=0.003 *
CG	21.18 ± 6.65	21.42 ± 9.6	1%	0.04				p=0.927
Extensors’ Endurance (s)
FT	106.62 ± 52,.9	121.00 ± 65.1	13%	0.27	p=0.010	p=0.509	p=0.918	p=0.017 *
TT	120.85 ± 73.3	128.7 ± 70.1	6%	0.10				p=0.226
CG	79.26 ± 46.5	81.3 ± 44.7	3%	0.04				p=0.819

* p ≤ 0.05 (statistical significance pre- to post-test).Data analyzed from a two way ANCOVA (3-group x 2 times), ES; (Effect size); N (Newtons); RFD (Rate of force development); s (seconds);