Fig. 9. Stride frequency vs mass-specific work per stride (W_c) for galloping horses (coloured lines). Data were categorised into 1 m s^–1 speed bins, and linear regression lines (solid lines) and 95% confidence intervals (broken lines) have been plotted. Each colour represents data from a 1 m s^–1 speed bin. Calculated work per stride and stride frequency from figures and data from Wickler et al. (Wickler et al., 2005) measured from trotting horses are also presented (black data points). As data are categorised into speed bins, moving from left to right represents an increase in incline.