Why do these two stations cause the most damage to race times?
Burpee broad jumps and wall balls share one characteristic that no other Hyrox station has to the same degree: they elevate the heart rate faster and higher than any other movement in the race. Both involve repeated ground-to-standing or standing-to-ground transitions with explosive effort on every rep. Both require the cardiovascular system to sustain near-maximum output for multiple minutes. Both punish athletes who arrive unprepared with a disproportionate time loss.
The burpee broad jumps occur at station four, after four kilometres of running and three previous station sets. The body is already significantly fatigued. The burpee broad jump demands a full ground-to-standing jump on every rep. Eighty metres of these at any meaningful pace produces a heart rate spike that compounds directly into the subsequent run. Beginners who go hard on station four consistently run kilometre five the slowest of the race.
The wall balls occur at station eight, the final station. One hundred repetitions of a squat-to-throw to a target two and a half metres high. The shoulders are fatigued from the ski erg, the farmers carry, and the sandbag lunges. The legs are fatigued from everything. And the wall ball demands both simultaneously for a hundred reps. Athletes who arrive at station eight without specific wall ball conditioning break their sets early, rest for longer than planned, and spend significantly more time on the final station than the race plan assumed.
Common misconception: burpees in the gym prepare you for burpee broad jumps in Hyrox. Standard burpees and burpee broad jumps are different movements. A standard burpee finishes with a vertical jump. A burpee broad jump finishes with a maximal horizontal broad jump covering as much forward distance as possible per rep. The broad jump component requires specific practice to maximise distance per rep, which directly determines how many total reps are needed to cover eighty metres.
Similarly, wall ball practice in a fresh state in the gym does not replicate the wall ball demand after seven other stations. Practising wall balls after a simulated race sequence is the only training stimulus that specifically prepares the body for wall balls at station eight intensity. Athletes who train wall balls only fresh will almost always be surprised by how much harder the movement is at the end of a Hyrox race.