Notes from the coaching floor

The 220 minus age formula was never real science, and it misses a lot of people by 10 to 20 beats. Here is what is off, and what to use instead.

Does cardio blunt your strength and muscle gains? The molecular basis is real, but the everyday impact is much smaller than the fear suggests.

trainwell's FAQ says cancel anytime, no questions. Its terms say no refund for the term you've paid, up to three months on the quarterly plan. Both are true.

trainwell's FAQ says $149 a month, a landing page says $179, and its signup code shows a price test. What your price depends on, and how to pin it down.

Your heart runs about 10 beats slower in the pool at the same effort, so land zone 2 numbers read too easy. Here's how to gauge zone 2 while swimming.

Peloton Personal Trainer is trainwell's coaching inside Peloton, $99.99 a month on top of your membership, and Peloton says the workouts are asynchronous.

Cancel in the app's billing portal or at account.trainwell.net, a few days before renewal. What cancelling does, what it doesn't, and the Peloton exception.

trainwell is $149 a month billed every three months, so the charge is $447 and a year is about $1,788. The trial, the Peloton price, the history, what you get.

No, not as standard. trainwell's own blog says coaching is app-based and live workout sessions are scheduled separately. Here is what you get instead.

Carrying a loaded pack pushes an easy walk into zone 2 without a jog's impact. Here's the energy-cost science, the bone claim, and how to start safely.

An 8 percent grade at 3 mph costs about twice the oxygen of flat walking, so you reach a jog-level effort with no landing impact. The settings and the caveats.

The mortality data has a clear shape: big gains in the first hours, a plateau near 300 minutes a week. Here's how much zone 2 you actually need.