How heavy should I lift?

On Ep. 82, Nikkiey says you don't need to lift astronomical amounts. The question is how much you can lift, not what someone else is posting. She gives two ways to find your weight. The first is the feel test: the last three reps should make you push. If you're cruising through rep 10, or even the last five, pick up something heavier. The second is a numbers approach: do two or three heavy reps, put them into an online one-rep-max calculator, and plan your weeks from percentages of that max. This also works if you train alone and can't safely max out.

On Ep. 18 she explains how to adjust within a session. Use your first set to gauge the day. If 10 reps felt easy, go up five pounds, or 10 if five isn't enough. Don't jump 20 to 50 pounds, because your form will fall apart. The weight you want leaves the last reps hard, with maybe two or three more in the tank at good form. On Ep. 281 she adds that over time you should be raising your weights, often by five to 10 pounds every week or two depending on the exercise. Doing the same workout you did six months ago won't change much.

If fear of injury is what holds you back, Nikkiey says on Ep. 281 that this is often a story rather than a fact. Women in their late 40s, 50s and 60s can and should lift heavy, building up gradually and with good form. If you have a past injury, train within what you can do safely.