Abstract

Purpose. This study aimed to investigate the reliability of surface electromyography (EMG) assessed at seven muscles during three repeated 2000 m rowing ergometer sessions.
Methods. Twelve male well-trained rowers participated in a repeated measures design, performing three 2000 m rowing
ergometer sessions interspersed by 3–7 days (S1, S2, S3). Surface electrodes were attached to the gastrocnemius, biceps
femoris, gluteus maximus, erector spinae, vastus medialis, rectus abdominis and latissimus dorsi for EMG analysis.
Results. No differences existed between 2000 m sessions for EMG amplitude for any of the seven muscles (p = 0.146–0.979). Mean coefficient of variation of EMG for 6 of 7 muscles was ‘acceptable’ (12.3–18.6%), although classed as ‘weak’ for
gastrocnemius (28.6%). Mean intra-class correlation coefficient values across muscles ranged from ‘moderate’ to ‘very
large’ (0.31–0.89). Within-session EMG activation rates of vastus medialis were greater during 0–500 m and 1500–2000 m
segments, compared with 500–1000 m and 1000–1500 m (p < 0.05). Values for biceps femoris and gluteus maximus were
significantly higher during 1500–2000 m compared to 500–1000 m and 1000–1500 m (p < 0.05). The general pattern was
for higher activation rates during 0–500 m and 1500–2000 m compared to 500–1000 m and 1000–1500 m. However, there
were no between-sessions differences in EMG for any of the 500 m segments (p > 0.05).
Conclusion. Reliability of EMG values over repeated 2000 m sessions was generally ‘acceptable’. However, EMG was
seemingly not sensitive enough to detect potential changes in neural activation between-sessions, with respect to changes in pacing strategy.