Hybrid Training?
Is this weight training? Is this cardio? The answer likely lies somewhere in between. High-rep sets with reduced loads can accumulate volume for strength development, but also give the auld ticker a good workout too. Here I'm taking 141.5kg (312lbs/22st) for 10 reps in 25s for a hybrid strength training/HIIT set. These sets leave me breathless with jelly legs, similar to how I feel after a HIIT session on a stationary bike. I complete 10-12 sets like this every week and think that they contribute to maintaining a fairly decent level of cardiovascular fitness while also adding to my strength-building efforts.
If you've not seen it before, the Trap Bar used here is a useful bit of kit. Unlike the barbell deadlift where the centre-of-mass is pushed out in front, the hexagon shape of the Trap Bar allows you to stand inside the centre-of-mass, reducing stress on the lower back. I still highly recommend traditional barbell deadlifts and squats for strengthening the lower back (got rid of my own back issues this way), but the Trap Bar provides an option for adding more weekly volume to bigger muscle groups without increasing fatigue for the lower back.
I'm using it here in the capacity of a squat alternative, even though it looks suspiciously like a deadlift, it's still hitting the target of a good leg workout. I've used it in the past for overhead pressing (no need to move your chin out of the way), and squat jumps with it can be quite fun. It also simplifies some of the technical complexities of the barbell deadlift, making it a good option for beginners with decent coverage of both squat and deadlift bases.
More info on the Trap Bar: https://www.strongerbyscience.com/trap-bar-deadlifts/