They contained blood, usually their own, which had a higher level of deliciousness than regular blood. This blood was removed at a time when it was at its peak deliciousness (while not in the middle of a long-ass race) and was put back in to re-deliciousfy the racer - that is, replace depleted flavours so they could race as if they'd had more time to recover.
They contained blood, usually their own, which had a higher level of deliciousness than regular blood. This blood was removed at a time when it was at its peak deliciousness (while not in the middle of a long-ass race) and was put back in to re-deliciousfy the racer - that is, replace depleted flavours so they could race as if they'd had more time to recover.