Is there any scientific evidence that suggests that cardio - steady-state or HIIT - is better (or worse) for muscle/strength gains if it’s done before or after a training session with weights? How about from your personal experience?
For instance, in the GPP days workouts. Should cardio be done before or after the weights exercise in order to maximise gainzzz?
There’s not really a consensus here to give a definitive answer for all situations. Fortunately, there is quite a bit of data in order to make a more informed decision.
In general, the type of exercise you do first benefits from having less fatigue on board. When conditioning work is performed first, time to exhaustion is increased and the sustainable pace is higher, for example. When resistance training is done first, the amount of weight lifted tends to be higher for a given exertion level and more volume can be completed prior to muscular failure. The opposite is true when the order is reversed.
As far as adaptations go, there doesn’t really seem to be a difference from a health perspective. Performance-wise, maximal strength and endurance adaptations do some to prefer prioritization to some degree.
For GPP, I don’t think it matters that much. If you were engaging in lots of structured conditioning however, I’d probably do strength training first (or in a separate session) if you were trying to maximize strength and/or hypertrophy.