. 2015 Sep 23;6:260. doi: 10.3389/fphys.2015.00260

Table 3.

Surface EMG median power frequency (MPF).

Variables (% sprint 1)	Sprints				ANOVA p-value (partial eta-squared)
	4	8	9	12	Condition	Time	Interaction
RMS vastus lateralis
SL	96.1±10.0^a	94.2±13.0	97.7±10.9	94.3±11.9	0.977	0.024	0.923
MH	95.4±13.0^a	95.0±12.6	98.0±12.3	93.9±16.0	(0.02)	(0.21)	(0.03)
SH	99.2±8.4^a	93.2±10.0	94.4±13.8	92.9±14.4
RMS rectus femoris
SL	99.9±5.2^a	96.4±7.6^a ^b	98.8±8.6^c	99.0±10.6	0.186	<0.001	0.167
MH	89.6±10.9^a	88.8±8.8^a ^b	97.5±11.6^c	95.1±14.1	(0.14)	(0.42)	(0.13)
SH	94.1±10.3^a	87.6±13.1^a ^b	94.2±13.2^c	89.3±16.4
RMS biceps femoris
SL	96.2±7.2	95.9±10.9	90.0±16.4	90.1±18.7	0.208	0.046	0.509
MH	99.3±12.2	94.8±13.0	95.1±15.6	94.4±11.8	(0.12)	(0.23)	(0.07)
SH	105.1±6.1	101.7±10.8	94.2±11.2	97.1±14.9
RMS gastrocnemius medialis
SL	98.7±9.3	99.4±9.2	92.9±12.3	93.3±8.8^a	0.886	0.027	0.341
MH	94.8±7.4	92.7±10.6	96.0±11.1	95.2±11.5^a	(0.01)	(0.20)	(0.09)
SH	97.8±10.0	97.4±10.9	95.0±9.8	94.3±10.0^a
RMS gastrocnemius lateralis
SL	96.8±5.1	99.9±9.3	95.1±7.7^a	98.9±12.2	0.264	0.011	0.607
MH	97.4±6.3	94.4±11.5	94.9±12.6^a	94.1±8.3	(0.11)	(0.23)	(0.06)
SH	95.8±9.4	94.6±10.7	91.7±12.3^a	91.2±11.2
RMS tibialis anterior
SL	97.2±9.3	99.7±10.8	96.3±6.9	98.2±11.5	0.663	0.011	0.605
MH	97.5±5.9	94.5±10.1	96.3±15.8	93.3±13.9	(0.03)	(0.23)	(0.06)
SH	97.9±5.6	95.7±11.0	91.8±8.4	96.7±6.5

Mean ± SD (n = 13). The repeated-sprint exercise protocol included a first set of 8 sprints performed at sea level (SL), moderate (MH) or severe hypoxia (SH), while the second set of 4 sprints was always performed at SL.

^{a, b, and c}

significant different from sprint 1, 4, and 8, respectively (P < 0.05).