Here’s the medical logic behind it:
When an arterial wall is damaged, an enzyme called thromboxane A2 alters the expression of a surface protein in platelets, to encourage them to aggregate. Aspirin stops the production of the precursors to thromboxane, and prevents that process from occurring.
There is a drawback, in that many of the enzymes involved in this process are also a part of the systemic inflammatory response, which is ultimately what drives supercompensation from the small-scale damage of training. There is evidence that aspirin may impair portions of pathways known to be central to getting swole as fuck.
Baby aspirin seems to hit a sweet spot, where it inhibits platelet formation to reduce platelet aggregation, but won’t shut down the inflammation needed for hypertrophy.
In regular practice, low-dose aspirin isn’t universally recommended to all patients aged 60+ without a specific risk profile anymore. There was never great evidence for that regime anyway, but the prospective harm was so low that the trade-off seemed beneficial. After decades of millions of people taking it, the risk of bleeds and GI issues began to outweigh the perceived prophylactic effect. Now, it’s recommended to premillennialism with previous heart conditions or certain other elevated risk factors.
For someone on gear, blood pressure, blood lipids, and hematocrit can become problematic, and they all contribute to the class of negative cardiac outcomes baby aspirin can address. Enteric coating can ameliorate the GI issue, and unless your liver is trashed to shit already, 81 mg isn’t going to do anything.
TLDR - cheap, effective where it counts, and unlikely to do harm. Worth a shot, at least.