This guide gives you a conversion cheat sheet, explains why gym units matter more than you would think, and shows how to avoid the small errors that make progress look like a plateau.

How many kg in a stone, and a pound?

The pound is defined as exactly 0.45359237 kilograms, a value fixed by the International Yard and Pound Agreement that took effect on 1 July 1959 (Pound (mass), Wikipedia (opens in a new tab)). A stone is 14 pounds, so one stone comes to 6.35029318 kilograms.

To convert stone and pounds to kilograms, change everything to pounds first, then multiply by 0.4536. For 12 stone 5 pounds, that is (12 x 14) + 5 = 173 lb, and 173 x 0.4536 is about 78.5 kg.

Body weight in stone

Barbell weights

Why the unit matters in the gym

The unit is not just a label. It decides what you can load. Gyms in most countries stock kilogram plates, and many in the United States stock pound plates, so the smallest jump you can make differs. A common smallest kilogram pair adds 2.5 kg in total, which is about 5.5 lb. A common smallest pound pair adds 5 lb, which is about 2.3 kg.

That is why a programme written in kilograms can be awkward to follow with pound plates. A 20 kg bar is 44.1 lb, but a standard American barbell is 45 lb, or 20.4 kg. The difference looks tiny until you are loading 100 kg and trying to hit an exact number.

Small jumps matter for progressive overload. The method works best when you can add a small increment every few weeks. Use the units your gym's plates are marked in, so each step is something you can physically load.

Body weight and training weight can use different units

There is no rule that says you must pick one unit for everything. Plenty of people in the UK and Ireland think about body weight in stone and pounds but load barbells in kilograms, and many travellers think in pounds at home and kilograms abroad.

What matters is that each log uses one unit consistently. Your lifts should all be in the unit of the plates on the bar. Your body weight should all be in the unit you weigh yourself in. If you want to see the trend, tracking progress without the scale covers using a weekly average rather than daily readings.

Four ways unit mix-ups create false plateaus

1. Mixed units in one log. Logging 100 for one session in kilograms and 100 for the next in pounds shows a drop of more than half. Keep one unit per exercise.
2. Rounding on every conversion. Convert 100 lb to 45 kg and back, and you land on 99.2 lb. Do that a few times and your numbers drift. Convert once, from the original value.
3. Treating a pound plate as a kilogram plate. The difference between 2.5 kg and 2.5 lb is more than a kilogram of load.
4. Ignoring the bar. A 20 kg bar and a 45 lb bar are close but not equal. Know which one you are using.

The fix for all four is the same: choose your units once, set them in your tracking app, and let it do any conversion rather than doing it yourself in your head.

A simple way to choose

If you are not sure which units to use, decide in this order:

1. Lifts: match the plates and the bar in your gym. If the plates say kg, log kg.
2. Body weight: use the unit your bathroom scale shows, because you will read it without thinking.
3. Programmes and recipes from elsewhere: convert them once, at the start, to your own units, and round to something you can actually load or measure. A 135 lb target becomes 60 kg on a kilogram bar, not 61.2 kg.
4. Changing your mind later: pick a quiet week to switch, note the date, and avoid comparing numbers across the switch by eye. A week of overlap is enough to see that nothing has really changed.

Other units worth knowing

Fitness tracking is full of paired units. These are the ones that tend to cause confusion.

• Height: centimetres, or feet and inches.
• Distance: kilometres, or miles. One mile is about 1.609 km.
• Liquid: millilitres, or fluid ounces. Note that UK and US fluid ounces differ slightly.
• Energy: kilocalories (kcal), or kilojoules (kJ). In the UK, food labels must include the amount of energy in both kilojoules and kilocalories (NHS, how to read food labels (opens in a new tab)). One kcal is 4.184 kJ.

If you have ever compared a recipe from a UK website with one from an American one, you have already met the problem. A good tracker lets you choose the units you want for each kind of measurement and leaves the arithmetic to the app.

How VivFit handles units

VivFit is built for every country. You can choose Metric, US or UK, or mix your own: kilograms, pounds or stone and pounds, centimetres or feet and inches, kilocalories or kilojoules, and so on. The point is that the app shows numbers the way you think about them, so you are not converting in your head halfway through a set. You can see it listed in the FAQ on the home page. VivFit is coming soon to iPhone and Android, and you can join the waitlist for launch news.

Frequently asked questions

How many kilograms are in a stone?

One stone is 6.35 kilograms, to two decimal places, because a stone is 14 pounds and a pound is 0.45359237 kilograms. As a shortcut, multiply the stone figure by 6.35. For example, 11 stone is 69.9 kg.

How do I convert stone and pounds to kilograms?

Convert the whole weight to pounds by multiplying the stone figure by 14 and adding the pounds, then multiply by 0.4536. For 12 stone 5 pounds, that is 173 pounds, or about 78.5 kilograms. Round once at the end, not at each step.

Should I use kg or lb for lifting?

Use whichever matches the plates in your gym and the way you think. Kilograms are used in most countries and in most programmes written outside the US, while pounds are common in American gyms. The two systems work equally well for progressive overload as long as you stay consistent and can load a small increment.

Is a 45 lb barbell the same as a 20 kg barbell?

Almost, but not exactly. A 45 lb bar weighs about 20.4 kg, so it is roughly 0.4 kg heavier than a 20 kg bar. That is small, but it adds up when you compare numbers across programmes or gyms, so check which bar you are using before you log a lift.

Can I use different units for body weight and lifting?

Yes. Many people log body weight in stone and pounds and lifts in kilograms. Keep each measurement in one unit, and avoid converting between them in your log, so your trends stay clean.

Sources

• Wikipedia. Pound (mass) (opens in a new tab): definition of the international avoirdupois pound as exactly 0.45359237 kg (International Yard and Pound Agreement, 1959).
• NHS. How to read food labels (opens in a new tab).

Weight still has a place, as this guide explains. It just should not be the only thing you look at, and it should never be the thing that decides how you feel about your week.

Why the scale is a poor judge on its own

Body weight moves for reasons that have nothing to do with training. Food and drink in your system, water, salt and the day of the week all push it around.

One study analysed 4,657 daily weight measurements from 80 adults. It found a weekly rhythm: weight was highest early in the week, around Sunday and Monday, began rising on Saturday and fell through the week from Tuesday. The authors concluded that weekend-weekday swings should be seen as normal rather than as signs of gain (Orsama et al., 2014 (opens in a new tab)).

Weight also cannot tell you what changed. The NHS notes that BMI, which is built from weight and height, cannot tell the difference between muscle and fat, so someone with a lot of muscle can be placed in the overweight category without much body fat (NHS, obesity (opens in a new tab)). The same blind spot applies to the scale.

Signal 1: Strength and performance

If you train, your log is your best progress record. More reps at the same weight, the same weight for easier reps, a faster route, an exercise you could not do last month: these are direct evidence that you are improving, and they are not affected by what you ate yesterday.

Write down the weight, sets and reps, and note when you hit a personal record. If you are new to structured lifting, progressive overload for beginners explains how to add a little each week. A rising estimated one-rep max is one of the most motivating graphs you can have.

Signal 2: Progress photos

Photos show changes in shape and posture that numbers miss. They are also easy to get wrong, because small differences in light and angle can look like big differences in your body.

Keep conditions identical:

• Same place and light. A spot by a window or under the same lamp, with the camera at the same height.
• Same time of day. Mornings are usually the most consistent.
• Same poses. Front, side and back, relaxed, arms by your sides.
• Same clothing. Fitted clothes you are comfortable in.
• Same schedule. Every two to four weeks is plenty. Daily photos mostly show the lighting.

Keeping progress photos private

Progress photos are among the most personal images on your phone, so decide where they live before you take the first one.

• Keep them out of your main photo library and any automatic cloud backup you do not control.
• Use a lock, such as Face ID or a PIN, on whichever app holds them.
• Share a comparison with someone only when you choose to, and think about hiding your face or any numbers first.

VivFit's Journey is built around this. Photos are locked behind your phone's unlock, thumbnails stay blurred until you tap Reveal, you can compare any two days side by side, and the share studio can blur your face and hide numbers before anything leaves the app. Journey photos are never used for ads or to train AI, and support cannot see them. The detail is in the trust section of the home page, and the privacy policy has the legal text.

Signal 3: Measurements

A soft tape measure and two or three measurements can show changes that weight hides.

1. Pick your spots. Waist (at the navel), hips at the widest point, chest, and one thigh or upper arm.
2. Measure the same way. Same landmarks, relaxed, the tape snug but not tight.
3. Measure monthly. Weekly is too noisy to read, and daily is a recipe for frustration.

The NHS gives one simple reference point for waist: keep it to less than half your height (NHS, obesity (opens in a new tab)). It is a general health guide, not a target to chase.

If measuring makes you anxious, skip it. Nothing here works if it makes you feel worse.

Signal 4: How you feel

The most underrated data is the least technical. Notice and write down, once a week:

• Energy through the day.
• How well you slept.
• Mood and stress.
• How your clothes fit.
• How you feel on stairs, carrying shopping or playing with children.

None of this is precise, but it moves in the same direction as real change. If you also use a readiness score, how to read it shows how to set it beside these feelings instead of trusting either alone.

Signal 5: Consistency

Progress is easier to keep when the thing you track is something you control. Count the sessions you completed, the days you logged food, and the nights you hit your usual bedtime. Habits you repeat for months will beat any short burst of effort, and a streak you can see is motivating without being punishing.

VivFit's weekly review summarises this in plain words: sessions done, days of food logged, your streak and one change to try next week.

If you still use the scale

You can, and plenty of people find it useful. Make it work for you:

• Weigh at the same time, ideally first thing, after the toilet and before eating.
• Use a trend, not a day. Look at the average over a week or two. Single readings mostly record water and last night's dinner.
• Know why you are weighing. If the number changes your mood for the day, weigh less often.

VivFit works with trend weight rather than daily readings, and shows weight in your own units. See tracking in kg, lb or stone for how that works.

A simple routine

When not to track

Tracking should support you. If counting, measuring or photographing makes you more anxious, preoccupied with food or critical of your body, that is a sign to stop and talk to someone. Your GP is a good first call. In the UK, the charity Beat (opens in a new tab) offers information and support about eating disorders. This is general guidance and not a substitute for professional care.

Frequently asked questions

How often should I take progress photos?

Every two to four weeks is enough for most people. Changes in body shape take time to show, and more frequent photos mostly capture differences in lighting, posture and time of day. Use the same place, light, poses and clothing so that the comparison is fair.

Does the scale matter at all?

It can be one useful data point. Body weight shifts for many reasons, including food and water, and it cannot tell muscle from fat. Used as a weekly average alongside strength, photos, measurements and how you feel, it is helpful. Used alone, one daily reading is mostly noise.

Which measurements should I take?

Waist, hips, chest and one limb, such as a thigh or upper arm, are plenty. Measure at the same spot each time, relaxed, with the tape snug but not tight, and repeat monthly. If measuring is stressful, leave it out.

Is it normal for weight to go up when I start training?

Weight can move up or down in any week for ordinary reasons, and one number cannot tell you what changed. That is why strength, photos and how you feel are worth tracking alongside it. If a change worries you, speak to a doctor.

How do I keep progress photos private?

Store them in an app with a lock rather than your main gallery, check what your phone backs up automatically, and share only on purpose. Hide your face and any numbers before sharing a comparison. VivFit's Journey locks photos behind Face ID or a PIN and blurs thumbnails until you reveal them.

Sources

• Orsama AL et al. Weight rhythms: weight increases during weekends and decreases during weekdays (opens in a new tab). Obesity Facts, 2014.
• NHS. Obesity (opens in a new tab).
• Beat. Beat eating disorders (opens in a new tab).

That one idea, written down and repeated for months, is most of what a beginner strength programme needs. The rest of this guide covers how to apply it without getting hurt, bored or stuck.

What is progressive overload?

Your muscles and nerves adapt to the demands you place on them. Lift a weight that feels hard and your body gets better at lifting it. Keep lifting the same weight for the same reps and, after a while, there is nothing new to adapt to.

"Progressive" is the important word. The increase should be small enough to manage and regular enough to matter. The American College of Sports Medicine's position stand on progression in resistance training describes it as a planned, gradual process tailored to your goals and experience, and says beginners should use loads of about 8 to 12 repetition maximum (RM) for two to three sessions a week (ACSM, 2009 (opens in a new tab)).

"8 to 12 RM" is a weight you could lift for at least 8 reps but no more than about 12 before form breaks down. In practice, you choose a weight that makes eight clean reps feel like work.

The ways you can progress

Adding weight is the famous one, but it is not the only one, and it is rarely the first to move.

Change one lever at a time. If you add weight, reps and sets in the same week, you cannot tell which one caused a stall or a niggle.

A simple method: double progression

Double progression is the easiest rule to follow, and it works for beginners because the first step is always "do one more rep".

1. Pick a rep range, for example 8 to 12.
2. Choose a starting weight where you can finish 3 sets of 8 with good form and feel you could have done a couple more reps.
3. Add reps each session. When you can do 3 sets of 12 with good form, you have earned a weight increase.
4. Add the smallest weight increase available and drop back to 8 reps. The new weight will feel harder, which is the point.
5. Repeat.

Here is how it can look for a dumbbell goblet squat:

It is slow on purpose. A couple of kilograms a month on a lower-body lift is real progress when you add it up over a year.

How heavy do you need to lift?

Heavier than a warm-up, but not as heavy as people fear. A meta-analysis of 21 studies comparing low-load and high-load training found that heavier loads produced greater gains in one-repetition maximum strength, while muscle growth was similar across loading ranges (Schoenfeld et al., 2017 (opens in a new tab)).

For you, that means two things. If you are building strength, heavier work helps. If you are mainly after muscle and only have light dumbbells at home, taking sets close to hard still counts. The 8 to 12 range is a sensible middle for most beginners, and it is easier on your joints than grinding out heavy singles.

A useful cue is "reps in reserve": finish most sets with one to three good reps still in the tank. That is coaching guidance rather than a research finding, but it keeps technique tidy and recovery manageable while you learn.

How often should you train?

For most adults the baseline is the same everywhere. The NHS recommends strengthening activities that work all the major muscle groups on at least two days a week (NHS physical activity guidelines (opens in a new tab)). The ACSM figure for beginners is two to three sessions a week. A simple split is two or three full-body sessions with a rest day between them.

More is not automatically better. Muscles get stronger while you recover, not while you lift, which is why sleep and food matter. If your energy and mood are dropping, our guide to reading a daily readiness score shows how to tell tiredness from a real need to back off. Protein is the other half of the equation, and how much protein you need covers the numbers.

Write everything down

A training log is the cheapest piece of equipment you will ever buy. Without it you will guess last week's weights, repeat them for months and wonder why nothing changes.

Record, for each exercise: the weight, the sets and reps, and one line on how it felt. You are not trying to prove anything, only to know what "one more rep" means this week.

VivFit's Train screen logs sets, weights and reps as you tick them off, flags personal records, and shows an estimated one-rep max rising over several weeks so you can see progress that does not show up on the scale.

When progress stalls

Every lifter stalls. These are the usual suspects, in order of how often they are the answer:

1. Sleep and food. Short sleep and too little food make everything harder. Check these first.
2. Too many changes at once. Go back to one lever.
3. The jump was too big. Take a smaller step, such as 1 kg instead of 2.5.
4. You need a lighter week. A common approach is to cut sets or weight by about a third for a week, then resume.
5. The rep range is stale. Try 6 to 10 or 10 to 15 for a few weeks.

Stalling for two weeks is normal. Stalling for two months means it is time to change something, not to try harder at the same thing.

Common beginner mistakes

• Adding weight every session. It works for a few weeks, then it does not. Use reps first.
• Skipping the log. If it is not written down, you will repeat last week by accident.
• Swapping programmes every fortnight. Progression needs repetition. Give a plan eight to twelve weeks.
• Letting form slide to hit a number. A rep that does not look the same as the first one does not count.
• Ignoring pain. Muscle fatigue is normal. Sharp, persistent or joint pain is a reason to stop and speak to a doctor or physiotherapist.

How VivFit applies progressive overload

VivFit's Train section builds sessions around your time, equipment and recovery, and applies progressive overload to your sessions. The plate calculator tells you which plates to load, and the plan eases off on days when readiness is low. You can see how sessions adapt on the home page, and you can join the waitlist for launch news. VivFit is coming soon to iPhone and Android.

Frequently asked questions

How fast should I add weight?

As slowly as it takes. Use the double progression rule: add reps until you reach the top of your range, then take the smallest weight jump available. On most lifts that is around 1 to 2.5 kilograms. If you cannot hold the lower end of the rep range after a jump, the step was too big.

How many reps should a beginner do?

The ACSM suggests 8 to 12 repetition maximum for beginners, which in practice means a weight that makes eight clean reps feel hard. Muscle growth was similar across heavy and light loads in the meta-analysis above, so the rep range matters less than finishing sets close to hard with good form.

Can I use progressive overload with bodyweight or dumbbells at home?

Yes. Add reps first, then slow the lowering phase, pause at the hardest point, use a fuller range of motion or move to a harder variation, such as a push-up with your feet raised. Small dumbbell increments or a backpack also work.

How long until I see results?

It varies, and anyone who gives you a date is guessing. Strength gains tend to show in your log within weeks, long before they show in the mirror. Judge progress by what you lift, how you recover and how you feel, not by one measurement.

What if I miss a session?

Pick up where you left off. One missed session does not undo anything. If you have missed a week or more, drop the weight a little for your first session back and rebuild.

Sources

• American College of Sports Medicine. Position stand: progression models in resistance training for healthy adults (opens in a new tab). Medicine and Science in Sports and Exercise, 2009.
• Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis (opens in a new tab). Journal of Strength and Conditioning Research, 2017.
• NHS. Physical activity guidelines for adults aged 19 to 64 (opens in a new tab)

The method is simple. What decides whether it survives past week two is how you handle the awkward bits: the night you are out, the recipe you cannot be bothered to cook, the half-used bunch of coriander. This guide covers both.

Why plan meals at all?

Because most of the stress is in the daily decision, not in the cooking. If dinner is already chosen and the ingredients are in the house, you remove the 6 pm scramble that tends to end in a takeaway or a snack-plate.

There is some evidence behind it. A study of 40,554 French adults found that about 57% planned meals at least occasionally, and that people who planned had higher odds of eating a more varied diet and following national nutrition guidelines more closely (Ducrot et al., 2017 (opens in a new tab)). It was an observational study, and the authors are clear that no causality can be inferred. Planning might make you eat better, or people who already eat well might plan. Either way, it makes the week easier to run.

Step 1: Look at your week first

Before you choose a single recipe, open your calendar. Mark the nights you will be out, the evenings you train late, and the days that will be rushed. A plan that ignores your real week fails by Wednesday.

Count the dinners you actually need to cook. If three nights are accounted for, plan four, not seven.

Step 2: Shop your kitchen

Check the fridge, freezer and cupboards and write down what needs using soon. Build at least two meals around those items. This is the single easiest way to cut waste, and it makes the week's shop smaller.

Step 3: Use a skeleton, not a blank page

A blank page gives you decision fatigue. Start with a skeleton and fill the gaps.

Repeating breakfasts and lunches is not boring, it is efficient. Most people eat from a small rotation anyway, so making it deliberate takes one big decision off the table every morning.

Step 4: Build each meal from the same parts

A balanced plate needs a protein food, a starchy food and plenty of vegetables. The NHS Eatwell Guide shows fruit and vegetables making up just over a third of what we eat, with at least five portions a day, and starchy foods another third, ideally higher-fibre or wholegrain (NHS Eatwell Guide (opens in a new tab)).

Choose the protein first, then add a starch and two vegetables. It is quicker than starting from recipes, and it makes it easy to hit a protein target without counting every gram. If you want a number, how much protein you need shows the sums.

Step 5: Write one list, once

This is the step that saves the most time, and the one most people do backwards. Do not make a list per recipe. Add each ingredient to a single list as you choose each meal, merging duplicates as you go.

Here is how three recipes collapse into one list:

The merged list reads "4 onions, 2 peppers, 4 carrots", not nine separate lines. Then:

1. Cross off what you have. Check the pantry for stock, oil and spices.
2. Group by section. Produce, fridge, tins and dry goods, freezer. You walk the shop once, in order, instead of doubling back.
3. Add staples last. Milk, bread, eggs, the breakfast items.
4. Keep it where you will see it. A list you can add to from your phone is a list you will use.

Step 6: Cook once, eat twice

Cook a double portion of whatever suits it: chilli, curry, soup, pasta sauce. One portion is dinner, the other is Thursday's lunch or goes in the freezer.

Food safety matters most with batch cooking. The Food Standards Agency's guidance on chilling, freezing and defrosting explains how to cool food quickly and store it safely, and it is worth reading once (How to chill, freeze and defrost food safely (opens in a new tab)).

Step 7: Take five minutes at the end of the week

Look at what was left uneaten. If the same item went in the bin twice, drop it. Then note the two meals you actually enjoyed and put them on a short "repeat list" of ten dependable dinners. After a month, planning mostly means choosing from that list.

Why meal plans fall apart, and the fixes

• It was too ambitious. Seven new recipes is a project, not a plan. Make one new recipe a week and repeat the rest.
• There was no slack. Always leave one flexible night. Plans without slack break at the first change.
• The shop was wrong. Usually the list was made per recipe and missed shared items. Merge the list.
• You got bored. Rotate the flavour, not the structure. The same chicken-and-rice base with a different sauce is a different dinner.
• Fresh food went off. Put the meals that use soft herbs, salad and fish at the start of the week, and the tinned, frozen and dried meals at the end.

How VivFit helps with this

VivFit's Kitchen puts the pieces in one place: recipes, a weekly meal plan with calories and protein per day, a grocery list that merges items from the week's meals into aisles, a pantry, and a cook mode for the stove. Because the plan sits next to your training and recovery, it can reflect how your week is going rather than treating food as a separate project. You can see how it fits together in the features overview, and the app is coming soon, so you can join the waitlist for launch news.

Frequently asked questions

How do I start meal planning as a beginner?

Plan four dinners only, and repeat breakfasts and lunches. Check the calendar, use up what you already have, and write one merged shopping list. Do it once a week at a fixed time. Add a second planned meal type only when the first feels easy.

How long should meal planning take?

About 20 minutes once you have a routine. The first few weeks take longer because you are building a repeat list of meals you like. After that, you are choosing from a short list rather than starting from scratch.

How many meals should I plan for a week?

Plan the meals you will cook, not every meal. Four dinners, two breakfasts and two lunches usually cover a normal week once leftovers, one flexible night and the odd meal out are counted. Planning less leaves room for real life.

Does meal planning help you eat better?

In one large French study, people who planned meals tended to have a more varied and better-quality diet, but the study cannot show that planning is the cause. Planning is a practical tool: it makes healthier choices easier when you are tired. It is not a guarantee about any outcome.

Do I need to plan snacks?

Only loosely. Put three to five snack items on the list that you will actually eat, such as fruit, yoghurt, nuts, oatcakes or hummus, and leave it there. Trying to schedule every snack usually backfires.

Can I meal plan on a tight budget?

Yes. Build the plan around what you already own, use frozen vegetables and tinned pulses, cook double and freeze the rest, and write one list so you do not buy duplicates. Planning mainly reduces the unplanned extras that add up.

Sources

• Ducrot P et al. Meal planning is associated with food variety, diet quality and body weight status in a large sample of French adults (opens in a new tab). International Journal of Behavioral Nutrition and Physical Activity, 2017.
• NHS. The Eatwell Guide (opens in a new tab).
• Food Standards Agency. How to chill, freeze and defrost food safely (opens in a new tab).

The rest of this guide shows you how to turn those numbers into your own target and how to spread it across a normal day, without weighing every meal.

How much protein do you need per day?

There is no single answer, because "need" depends on what you are asking. The UK reference figure is the minimum to avoid deficiency. The research on training is about getting the most from your effort. And older adults sit in a third category.

The first row is the Reference Nutrient Intake, which the British Nutrition Foundation lists as 0.75 g per kilogram per day, or 55.5 g for men and 45 g for women aged 19 to 50. It comes from 1991 Department of Health figures, and average body weights have risen since (British Nutrition Foundation (opens in a new tab)).

The second row comes from a meta-analysis of 49 randomised trials with 1,863 participants. It found that protein supplementation increased strength and muscle size during resistance training, and that total intakes above roughly 1.6 g per kilogram per day added no further gains in fat-free mass (Morton et al., 2018 (opens in a new tab)). The point where gains stopped was not sharply defined, so treat 1.6 as a sensible target rather than a cliff edge.

The third row is from the PROT-AGE position paper, which recommends that adults over 65 average at least 1.0 to 1.2 g per kilogram and more when they exercise (Bauer et al., 2013 (opens in a new tab)).

How to work out your number

Pick the row that fits you, then do one multiplication.

1. Take your body weight in kilograms. If you think in pounds, divide by 2.2; if you think in stone, multiply stone by 6.35 and add the odd pounds divided by 2.2. (More on this in our guide to tracking in kg, lb or stone.)
2. Multiply by 0.75 for a baseline, or by 1.2 to 1.6 if you train with weights regularly.
3. Round to a number you can remember.

For a 70 kg person who lifts, 1.6 x 70 gives 112 grams. In pounds the same maths is roughly 0.7 grams per pound of body weight.

Two honest caveats. The research above uses averages, and individuals vary. And a target is a target, not a daily pass mark: a week averaging 105 grams when you aimed for 112 is a good week.

VivFit sets a protein target as grams per kilogram of your trend weight and shows it as a ring in Eat, so it adjusts as your weight changes instead of asking you to redo the sums. You can see how that fits with the rest of the plan in the Eat section of the home page.

Is more protein always better?

No. The trial data point to a plateau, which means extra grams beyond the range above buy you little extra muscle. Protein also does not replace training, enough food overall or sleep.

If you have a kidney condition, or you follow a diet set by a doctor or dietitian, ask them before raising your intake. The PROT-AGE authors, for instance, note that people with severe kidney disease who are not on dialysis may need to limit protein.

What does 100 grams of protein look like?

Rounded, typical values for common portions are below. Brands and cooking methods vary, so check the pack or a food database such as McCance and Widdowson's Composition of Foods (opens in a new tab).

A day that reaches roughly 110 grams might look like this:

• Breakfast: Greek-style yoghurt with oats, a splash of milk and fruit, about 25 g.
• Lunch: tuna and white bean salad with bread, about 40 g.
• Snack: cottage cheese on oatcakes, about 18 g.
• Dinner: chicken or tofu stir-fry with rice and vegetables, about 35 g.

Nothing in that list is a supplement or a special product. If you eat plant-based, the same shape works with lentils, beans, tofu, tempeh and soya milk, though the portions are usually larger for the same protein, so it is worth checking labels for the first week.

How to hit your target without turning dinner into maths

Anchor each meal with a protein food. Decide the protein first and build the plate around it. It is easier than patching a gap at 9 pm.

Aim for roughly even meals. Spreading protein across three or four eating occasions is practical. The trials above looked at total daily intake, so do not worry about hitting a precise number at each meal.

Keep two or three fallback options. A tub of yoghurt, a tin of fish or a carton of milk covers a short day.

Plan the week, not the day. Protein is much easier to hit when the shop and the recipes are decided on Sunday. Our guide to a weekly meal plan and one grocery list walks through it.

Vary the sources. The NHS Eatwell Guide advises eating some beans, pulses, fish, eggs, meat and other protein foods, choosing lean cuts and cutting back on red and processed meat, with at least two portions of fish a week, one of them oily (NHS Eatwell Guide (opens in a new tab)).

Do you need protein powder?

You do not. The meta-analysis above looked at supplementation, so it does not show that powders beat food. Powders are a convenient way to close a gap, particularly if you train hard, have a small appetite or are short of time. If you can reach your number with yoghurt, eggs, fish, pulses and meat, you have no need to buy anything.

Frequently asked questions

Is 0.75 g per kg enough?

It is the UK reference intake for adults, set to meet the needs of most people who are not doing resistance training for muscle. If you lift regularly, are older or are trying to maintain muscle, the research above points to a higher range. For a 70 kg adult, 0.75 g per kg is about 53 grams a day.

How much protein do I need to build muscle?

Across the trials in the Morton meta-analysis, intakes above about 1.6 g per kg per day gave no extra gain in fat-free mass. That is about 112 grams a day at 70 kg. Training, total food intake and sleep matter just as much as the protein figure, so treat it as one part of the plan.

Can you eat too much protein?

The studies above found no extra muscle benefit beyond the plateau, so there is little reason to go far above it. People with kidney conditions, or on a medically directed diet, should get advice before raising intake. If you are unsure, ask your doctor or a registered dietitian.

Do vegetarians and vegans need more protein?

The reference amounts are the same, and plant foods can meet them with variety. Pulses, soya products, grains, nuts and seeds all contribute. Portions of some plant foods need to be larger for the same protein, so it helps to check labels while you are learning what your usual meals provide.

Should I count protein every day?

Only if it helps. A few weeks of logging teaches you what 100 grams looks like on your plate, and after that many people check in once a week. Counting should make food easier, not more stressful. If tracking numbers affects how you feel about eating, stop and speak to your GP or an eating-disorder charity such as Beat.

Sources

• British Nutrition Foundation. Protein (opens in a new tab).
• Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults (opens in a new tab). British Journal of Sports Medicine, 2018.
• Bauer J et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group (opens in a new tab). Journal of the American Medical Directors Association, 2013.
• NHS. The Eatwell Guide (opens in a new tab).
• UK Government. McCance and Widdowson's Composition of Foods integrated dataset (opens in a new tab).
• Beat. Beat eating disorders (opens in a new tab).

That is the whole idea. The rest of this guide is about reading the number sensibly, because a score only helps if you know what moved it and what you are going to do about it.

What is a readiness score?

A readiness score is a summary. Your phone or watch gathers a handful of signals from the night, compares each one with your personal baseline, and folds them into one figure so you do not have to inspect three charts before breakfast.

There is no standard formula. Every app weights the inputs differently, which means a 78 in one app and a 78 in another are not the same statement. The useful comparison is always you against you: this morning against your last few weeks.

Most scores draw on some mix of these inputs:

• Heart rate variability overnight, compared with your usual.
• Resting heart rate, compared with your usual.
• How long and how steadily you slept, and whether the last few nights have added up.
• Recent training load, so a hard week counts.
• A short subjective check-in: how tired, sore or stressed you feel.

VivFit's readiness score uses signals of this kind, built from whatever you choose to share from Apple Health or Health Connect plus a quick daily check-in, and it shows the reasons beside the number so you can see what moved it.

The three signals behind most scores

Heart rate variability (HRV)

HRV is the variation in the time between consecutive heartbeats. A healthy heart is not a metronome: the gaps between beats shift constantly, and that variation reflects how your nervous system is adjusting to physical and mental demands (Shaffer and Ginsberg, 2017 (opens in a new tab)).

Two things matter for reading it. First, baseline HRV differs between people with age, sex and how it is measured, so your number means little next to a friend's. Second, a single night is noisy. The same review notes that recording length, age and sex all affect baseline values, which is one more reason trends over days beat any single reading.

Researchers who study training status make a related point. A review of heart-rate-based monitoring concluded that changes should be judged against measurement error and the smallest change that is worth caring about, and that these measures work best alongside training logs and questionnaires rather than on their own (Buchheit, 2014 (opens in a new tab)).

Resting heart rate

Resting heart rate is how fast your heart beats when you are calm and still. The NHS says most adults sit between 60 and 100 beats per minute, that the fitter you are the lower it tends to be, and that athletes may be at 40 to 60 beats per minute or lower (NHS, how do I check my pulse? (opens in a new tab)).

Notice how wide that range is. What matters for readiness is your own baseline. If you usually wake at 54 and today you are at 61, that gap carries more information than whether 61 is inside the textbook band.

Sleep

Sleep is the input people understand best and manage worst. A joint consensus statement from the American Academy of Sleep Medicine and the Sleep Research Society says adults should sleep seven or more hours per night on a regular basis to support optimal health (Watson et al., 2015 (opens in a new tab)).

The word that matters is "regular". One short night usually dents a score a little. A run of short or erratic nights moves it a lot, which is exactly what it should do.

How to read the number

Start with the direction, then look at the reasons. A score that is a few points off is noise. A score that sits well below your normal for several days, with the same signals pointing the same way, is worth acting on.

Two signals pointing the wrong way together are a stronger cue than either one alone. That is a rule of thumb rather than a research finding, but it matches the advice above to read measures in combination.

Four habits that make a score useful

1. Compare weeks, not mornings. Look at the last seven days against the last few weeks. A single bad morning tells you almost nothing.
2. Measure the same way. Wear the watch the same way, at the same time, and check in at a similar point each morning. Inconsistent measurement creates movement that is not physiology.
3. Add how you feel. The score can be high while you are heavy-legged, and low while you feel fine. Your own check-in is data too, and the monitoring research above recommends pairing numbers with questionnaires.
4. Do not chase it. Going to bed anxious about tomorrow's number is worse for your sleep than a mediocre score. If tracking starts to feel stressful, switch the number off for a fortnight.

What a low score does not mean

A low score is not a diagnosis, and it is not a reason to feel behind. These measurements are estimates from consumer devices, and accuracy depends on the device, how you wear it and how much you move in your sleep.

It also does not mean "do nothing". The NHS recommends adults aim for at least 150 minutes of moderate activity a week, plus strengthening work on two or more days (NHS physical activity guidelines (opens in a new tab)). A low-readiness day can still be a walk, some mobility work or a shorter session at an easier effort. The point is to match the day, not to cancel it.

If your resting heart rate is unusually high or low for you, your pulse feels irregular, or you feel unwell, that is a conversation for a doctor, not an app.

How VivFit uses readiness

On VivFit's Today screen the readiness score sits beside the reasons for it, so you can tell whether sleep, recent training or your check-in did the moving. The rest of the plan then follows: slept badly and the session eases off, busy week and it gets shorter. You can see how a day adapts on the home page.

The same principle is behind progressive overload: you want enough challenge to keep improving and enough recovery to absorb it, and a readiness score is one way to check the balance. VivFit is coming soon to iPhone and Android, and you can join the waitlist for launch news.

Frequently asked questions

What is a good readiness score?

There is no universal good number, because scores are built from your own baseline and each app uses its own formula. A good score is one that is at or above your usual range. Learn what normal looks like for you over a few weeks and treat movement away from it as the signal.

Is HRV or resting heart rate more important?

Neither is more important on its own. Heart-rate-based monitoring works best when several measures are read together and set alongside how you feel and what you have trained. A change in HRV and resting heart rate in the same direction is more convincing than either alone.

Should I skip training when my readiness is low?

Not necessarily. A low score is a reason to consider a lighter or shorter session, more sleep or an extra rest day, depending on how you feel. Staying active still counts towards weekly activity guidelines, so an easy walk is a fair swap for a hard session.

Do I need a wearable to get a readiness score?

You need some signals. VivFit can read sleep, steps and heart data from Apple Health or Health Connect when you allow it, and the daily check-in works without any extra device. Which signals feed your score depends on what you choose to share.

Is a readiness score medical advice?

No. It is general wellness information built from estimates. It cannot diagnose or treat anything. If something feels wrong, or a number worries you, speak to a health professional.

Sources

• Shaffer F, Ginsberg JP. An overview of heart rate variability metrics and norms (opens in a new tab). Frontiers in Public Health, 2017.
• Buchheit M. Monitoring training status with HR measures: do all roads lead to Rome? (opens in a new tab) Frontiers in Physiology, 2014.
• Watson NF et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the AASM and SRS (opens in a new tab). Journal of Clinical Sleep Medicine, 2015.
• NHS. How do I check my pulse? (opens in a new tab)
• NHS. Physical activity guidelines for adults aged 19 to 64 (opens in a new tab)