Affiliations: [a] Coaching Education Department, School of Physical
Education and Sports, Ege University, İzmir, Türkiye
Note: [] Corresponding author: Ekim Pekünlü, School of Physical
Education and Sports, Ege University, Postal Code: TR 35040, Bornova, İzmir,
Türkiye. Tel.: +90 232 3425714; Fax: +90 232 3399000; E-mail:
ekimpekunlu@gmail.com
Abstract: BACKGROUND: The randomization method (RM) is used as a gold
standard for creating equal groups in most independent-group design studies. OBJECTIVE: To identify whether the fatigue index (FI)-based matching
method could be an alternative for the RM in the context of forming equal
independent study groups using relative maximal isometric squat strength
(R-MISS) recovery data as the dependent variable. METHODS: Baseline R-MISS values of 30 resistance-trained male participants were assessed. FI was
calculated during an exhaustive training intervention (ETI), including four
sets of submaximal isometric squat contractions. Maximal isometric squats were
performed 30 seconds, and 2, 4, 6, 8, 10, 12, and 14 minutes after the ETI to
assess the recovery levels of R-MISS. For the statistical analyses, low- and
high-endurance groups, and two equal-endurance groups (each including 15
participants) were retrospectively formed based on FI scores. RESULTS: The results of the repeated-measures analysis of variance revealed that
recovery moments greatly differed (8 minutes) between the high- and
low-endurance groups but were similar between the two equal-endurance groups
(difference of 2 minutes). Simulations performed using the resampling procedure
revealed that the FI-based matching method was more successful than the RM
(71.6% vs. 56.2%) in the context of forming equal study groups. CONCLUSIONS: These results indicate that the FI-based matching method
is a better alternative to the RM for preventing an unequal distribution of
participants among independent groups in R-MISS recovery-related studies.
Keywords: Comparability, fatigue index, isometric contraction, resampling, testing study assumptions
