I’m not sure of the reason why but, I’ve experienced the same thing that you are talking about. My opinion is that, at least for me, it seems to be related to the rep range performed. Years ago, I mostly concentrated on the 10-12 rep range and would experience DOMS like crazy. Now that I mostly stay in the 1-5 rep range, I never seem to get any, regardless of the number of sets performed or the weight lifted. Thus, I think that these higher rep ranges must elicit a greater lactic acid response in the tissues than heavier weights done at a lower rep range. Just my humble opinion[/quote]
Wow, that actually makes perfect sense because when I used to lift years ago it was in the 8-10 rep range but since getting serious about lifting this past 3 months I’ve been using 5 rep sets in all my compound movements. I never for one moment thought about how rep range could be a factor in DOMS… but it definitely makes sense now.
Thanks for the heads up!
It’s a combination of both. Higher reps = more muscle microtears = more to inflame and cause soreness during repair, and capillary density from cardio and conditioning is a veeeery big determinant for soreness as well, because the capillary density gives you greater nutrient flow and oxygen flow so the oxygen debt is not as prolonged, and neither is the build-up of metabolic byproducts. Better circulation = less soreness for a variety of reasons.
The other variable is frequency of training (which plays into conditioning and cardio, but from the weights side). If you only hit a movement or body part 1 time a week the recovery process is very slow and never pushed. If however you start squatting 4-5 days a week and get to push your recovery abilities up, your body responds with better nutrient transport and increased capillary density to keep up with the constant work demands. This is maybe not quite as pronounced as doing cardio, but it is one reason olympic weightlifters almost never get sore (of course the eccentricless action of dropping the bar helps a ton too).