Timed Carries/Isometrics vs High Rep Sets

Coach Thibs,

I was wondering which you think would be better for size gains, reading up on the articles it highlights the use of isometrics as being good for hypertrophy and strength gains, but my question is;

If you was to carry on working a body part towards the end of a workout (i.e shoulders, arms, back), would a few sets of higher reps (e.g 6-8)or using a few sets of timed carries/isometrics be more effective for strength and/or size (e.g. 30 secs work, 30 secs rest with heavier weight as opposed to 1 min on and 1 min off)?

Thanks in advance,
Jake