Not even close to the most efficient gait. The videos I've been watching, they are using their hands plantigrade rather than digitigrade. They should be on their fingertips or knuckles, not their palms, and be wearing something like boxing gloves with cleats to protect their knuckles rather than their palms.

Their gaits are nearly symmetric: opposite limbs are contacting the ground at about the same time, much like a horse's trot rather than its gallop. Their asses are always high in the air, and their heads down; they are running like raccoons.

If you look at canine or feline running gaits, they rarely have more than one foot on the ground at any one time. Whenever one foot hits the ground, the other three are moving forward. They are making extensive use of the flexibility of their spine to lengthen their effective stride.

I noticed the runner used a bipedal start off traditional running blocks. Head down, legs bent, crouched forward, held back behind the line with straight arms. If you watch a dog, cat, horse, etc, as it starts to run, it is digging in with all four limbs, not just the hind legs.

I think in a quadrupedal race, the runner would want to be able to pull themselves forward with their arms as well as push themselves forward with their legs. That doesn't make sense for a bipedal runner, as that extra performance off the line comes with the penalty of extra upper body mass through the entire race. But a quadrupedal runner is going to need that mass/strength through the entire race.

I'd think they would want a modified starting block for their hands as well as one for their legs.