Purpose:
The study aimed to compare and correlate the power, height, eccentric and concentric force development rate of 3 sequential attempts of countermovement jump (CMJ) and the respective muscle response in beach and indoor volleyball athletes.

Methods:
The sample involved high-level hard court indoor volleyball (HCIV, n = 7) and high-level sand court beach volleyball (SCBV, n = 6) athletes. They performed 3 CMJs (1^st CMJ vs. 2^nd CMJ vs. 3^rd CMJ) to determine the height, eccentric force development rate (EFDR), concentric force development rate (CFDR), power, and lower limbs muscle electrical activity.

Results:
Difference was demonstrated between HCIV vs. SCBV players in 3^rd CMJ EFDR (–270.2 ± 31.6 N/s vs. –214.3 ± 38.7 N/s). In HCIV, 1^st CMJ was different from 2^nd CMJ and 3^rd CMJ in EFDR (–239.0 ± 27.3 N/s vs. –285.6 ± 40.2 N/s and –270.2 ± 31.6 N/s), CFDR (87.8 ± 24.4 N/s vs. 89.6 ± 25.7 N/s and 75.0 ± 23.6 N/s), and power (2341.8 ± 342.3 W vs. 2433.9 ± 327.2 W and 2411.0 ± 358.5 W). In SCBV, 2^nd CMJ was different from 3rd CMJ in EFDR (–267.1 ± 45.2 N/s vs. –214.3 ± 38.7 N/s). In 2^nd CMJ, the left gluteus presented lower electrical activity than the left medial gastrocnemius, and HCIV revealed a difference between the response of the right and left gluteus in 3^rd CMJ.

Conclusions:
Our analysis demonstrated ca. 70% of good or excellent intra-class correlation between the beach and indoor groups.