Table 2.

Intraclass Coefficients (ICCs) for the Comparison of Fitness Tests in Performers (n = 238) Over Time

Time Points	Test
	Dynamic Balance Lefta	Dynamic Balance Righta	Handgrip Left	Handgrip Right	Vertical Jump	Pull-Upsa	Harvard Step	60-Second Jump
Baseline versus 6 mob	0.23	0.06	0.86	0.86	0.92	0.90	0.58	0.49
Baseline versus 12 mo	0.25	0.29	0.89	0.89	0.88	0.87	0.56	0.39
Baseline versus 18 mo	0.23	0.24	0.85	0.81	0.89	0.84	0.46	0.34
6 mo versus 12 mo	0.50	0.38	0.88	0.90	0.93	0.94	0.67	0.72
6 mo versus 18 mo	0.44	0.35	0.84	0.83	0.94	0.91	0.60	0.66
12 mo versus 18 mo	0.45	0.51	0.88	0.84	0.94	0.94	0.64	0.75
Baseline to 18 mo	0.35	0.31	0.87	0.85	0.92	0.90	0.59	0.53
(95% confidence interval)	(0.28, 0.43)	(0.23, 0.41)	(0.84, 0.90)	(0.82, 0.88)	(0.89, 0.94)	(0.86, 0.93)	(0.52, 0.65)	(0.46, 0.60)
6 mo to 18 mo	0.46	0.42	0.87	0.86	0.94	0.93	0.63	0.71
(95% confidence interval)	(0.37, 0.55)	(0.33, 0.52)	(0.83, 0.90)	(0.82, 0.89)	(0.90, 0.95)	(0.89, 0.96)	(0.56, 0.69)	(0.66, 0.76)
6 mo to 18 mo,c performers who provided appropriate effort only (n = 215)	0.42	0.46	0.86	0.85	0.93	0.91	0.62	0.71

^a ICCs based on log-transformed data because of heteroscedasticity.

^b ICCs for each pairwise comparison are provided in the first 6 rows for transparency reasons only; confidence intervals are omitted to improve clarity.

^c Comparison to assess possible learning effects. The 95% confidence intervals were calculated using the bootstrap percentile method.²²