The talk test, forever
The most useful piece of training equipment this month is a sentence. If you can say a full one out loud while running, you are building your aerobic base. If you can only manage a word or two between breaths, you are racing, whether you meant to or not.
Lab testing for training zones costs a few hundred dollars. The talk test tracks the same boundary closely enough for almost everyone, costs nothing, and works on a bike, a rower, a hill or a run club Tuesday. Coaches have used it for decades because it keeps honest people honest at the exact moment their ego suggests ten seconds faster.
Field equipment for this week: one sentence, spoken to nobody. We stock everything else.