The things you keep hearing, checked.

Real overtraining syndrome exists, and it is rare. It shows up in elite endurance athletes doing huge volumes for months. For a man lifting three times a week and walking, it is not the problem. The usual causes of feeling wrecked are five hours of sleep, not enough food, a stressful job, or too much beer. The 2013 European and American consensus on overtraining says as much: it is a diagnosis of exclusion, and most people who think they have it do not.

Do instead: keep the sessions, fix the sleep and the food first. If you are still flat after two weeks of that, take a week easy. Then carry on.

Insulin does store energy. That part is true. But the idea that carbs are uniquely fattening because of insulin has been tested in tightly controlled feeding studies, and it did not hold up. Total calories drive fat gain. The debate is genuinely live in the journals (Kevin Hall on one side, David Ludwig on the other), so anyone telling you it is settled either way is overselling.

What is not in doubt: your insulin sensitivity, how well your body handles sugar, gets better with lifting, walking, losing fat around the middle, and sleep. You do not need to fear bread to get that. You need to move.

Do instead: lift, walk after meals, lose the belly. If you are over 45 or carry weight around the middle, ask your GP for an HbA1c blood test. In the UK, 42 to 47 is prediabetes and reversible. 48 and above, confirmed twice, is type 2.

Fasting works when it works because you eat less. That is the whole mechanism. In the best-known trial (TREAT, 2020), men doing 16:8 lost no more weight than men eating normally, and they lost more muscle. The muscle bit matters more past 40, because you are already losing it slowly.

That does not mean do not fast. Plenty of men find a shorter eating window is the easiest way to eat less without counting anything. It means: if you fast, lift, and hit your protein in the hours you do eat. Three big feeds, not two small ones.

Do instead: a 12 to 14 hour overnight fast suits most people. 16:8 is fine if you keep the protein up and keep lifting. The calculator has a fasting setting that builds the day around it. Do not fast if you are on diabetes medication without talking to your GP.

Your body absorbs all of it. What is true is that muscle building from a single meal tops out at a point, and for men over 40 that point is higher than for younger men, around 30 to 40 g. Anything above that still gets used, just for other things and more slowly. This is why big feeds on a fasting day are fine.

Do instead: aim for 30 to 40 g each meal. If you eat fewer meals, make them bigger.

In healthy men, intakes up to about 2 g per kilo show no harm to kidneys in the research. The concern is real for people who already have kidney disease, which is a different situation and a GP conversation.

Do instead: if you are healthy, eat your number. If you have kidney problems, ask before you change anything.

A hard interval session once a week does not stop you building muscle. Hours of running every day might blunt it a bit, but that is not what anyone here is doing. What the cardio session does do is raise your fitness and improve how you handle sugar, both of which matter more with every year past 40.

Do instead: lift two or three times, one hard cardio session, walk daily. The full plan is on the training page.

Visible abs need body fat somewhere around 10 to 12 percent. A man starting at 30 percent who does everything right will typically drop 4 to 7 kg of fat in 12 weeks, which is brilliant, and lands him around 24 percent. That is a smaller belly and looser trousers, not a six-pack. Anyone promising the six-pack is selling something.

Do instead: measure the waist, not the abs. A centimetre off the waist per kilo lost is a fair rule. In a year on the plan, ten kilos and ten centimetres is a realistic, life-changing result. We will not fake anything past that.

It is slower, not impossible. Across 49 trials of adults over 50, lifting added about a kilo of lean mass in roughly five months on average, and strength went up 20 to 40 percent in the first three months. That strength is what you feel: carrying the shopping, getting off the floor, not being knackered by stairs.

Do instead: start. Two sessions a week. Expect strength first, size later, and never bodybuilder size. Nobody needs that anyway.