Insight into muscle activity during deep water running.
OBJECTIVE
The purpose of this study was to compare muscle activity and patterns during deep water running (DWR) and treadmill running (TMR) at equivalent levels of RPE.


METHODS
Subjects (n = 7, 26.3 ± 4.3 yr, 158.2 ± 9.9 cm, 61.0 ± 6.6 kg) performed DWR and TMR at RPE values of 11 (fairly light), 13 (somewhat hard), and 15 (hard). Surface EMG was used to evaluate muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GA) with average EMG calculated across a 30-s window. Five cycles of data were extracted from smoothed EMG profiles on the basis of the selection of distinct RF peaks. These cycles were reduced to create ensemble muscle activity patterns per condition. Average EMG for each muscle was analyzed using a repeated-measures ANOVA with Bonferroni's post hoc tests.


RESULTS
TA and GA muscle activity magnitudes during DWR were significantly lower than during TMR (mean decrease of 72%-86%, P < 0.05) for any RPE level. BF and RF muscle activity magnitudes were either not different or tended to be lower during DWR than TMR for matched RPE (P = 0.051 and P = 0.121, respectively).


CONCLUSIONS
Whereas TA and GA muscle activity magnitudes were each clearly lower during DWR than TMR regardless of RPE, higher levels of intensity (RPE 15) during DWR can be used to elicit similar muscle activity levels as lower intensity (RPE 11) TMR.
Masumoto
Kenji
K
Department of Kinesiology, University of Nevada, Las Vegas, NV 89154-3034, USA.
Delion
David
D
Mercer
John A
JA
D000328:Adult; D000704:Analysis of Variance; D004576:Electromyography; D006801:Humans; D007101:Immersion; D007866:Leg / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013848:Thigh / Q000502:physiology; D014867:Water; D055815:Young Adult
D014867:Water