Research
What the research says about training and food.
30 questions, each with a short answer and how strong the evidence is. Every answer links to the full article with its sources.
Training 15
Sets, reps, effort, progression and recovery.
Coming back after a break
A break of a week or two costs you very little. After a few months you restart lighter, with about 10 to 30% less weight and fewer sets, and build back up over 2 to 4 weeks. Strength you built before comes back faster than it first took to get it. Mitta does not lower your target for a break, so you choose the restart weight yourself.
Do you need to train to failure?
No. Training to failure means you do a set until you cannot complete another rep with good form. Studies comparing it with stopping a rep or a few short of failure find little or no difference in muscle or strength gained, as long as the total work is similar. Most sets can end with 1 to 3 reps in reserve.
Does cardio kill your gains? Lifting and cardio in the same week
No, not for most people. A 2022 meta-analysis of 43 studies found that adding cardio to weight training did not reduce muscle growth or maximal strength. It did slow gains in explosive strength, mostly when both were done in the same session. If you do both on one day, lift first, and keep hard cardio away from heavy leg days where you can.
How long should you rest between sets?
For most lifters, 2 to 3 minutes on heavy compound lifts and 60 to 90 seconds on lighter isolation work is a good default. Longer rests tend to help strength, and for muscle size the differences are small once you rest more than about a minute. Rest long enough that your next set is not held back by the last one.
How many reps should you do?
For muscle size, a wide span of rep ranges works, from heavy sets of 8 or fewer to light sets of more than 15, as long as the sets are hard. For maximal strength, heavier sets do better. A range of 6 to 12 reps covers both goals well, which is why most plans live there.
How many sets per muscle per week?
Studies link more weekly hard sets per muscle with more muscle growth, but each extra set adds less. A broad, workable range is about 8 to 20 sets per muscle per week, starting at the low end and adding a few sets at a time. The right number depends on your experience and how well you recover.
How often should you train each muscle?
For muscle growth, how often you train a muscle matters less than how many hard sets you do for it in a week. Twice a week is a sensible default, because it lets you spread your sets over two sessions. For strength in a specific lift, practising it two or three times a week tends to help.
RIR vs RPE: what’s the difference?
RIR counts how many reps you had left when a set ended. RPE rates how hard the set was on a scale of 1 to 10. In strength training the two are tied together: RPE 10 means no reps left, RPE 9 means one, RPE 8 means two. They describe the same effort, so pick whichever you find easier to judge.
What counts as a hard set?
A hard set is a work set that ends close to failure: roughly 0 to 3 reps in reserve. Warm-up sets do not count, and neither does a set that felt easy. There is no exact cutoff in the research, so treat it as a rule of thumb. Mitta counts every finished set that is not a warm-up.
What is estimated 1RM, and how accurate is it?
Estimated 1RM is the heaviest weight you could lift once, worked out from a set of several reps instead of a max test. The common Epley formula multiplies your weight by 1 plus the reps divided by 30. It works well for sets of up to about 10 reps, and gets less reliable above that.
What is progressive overload, and how do you do it?
Progressive overload means asking a little more of your muscles over time, so they keep a reason to adapt. You can add weight, add reps or add a set. For most people the simplest way is double progression: add reps at the same weight until you reach the top of your rep range, then add weight.
What is RIR, and how do you estimate it?
RIR stands for reps in reserve. It is the number of reps you could still have done when you ended a set. If you stop at 8 reps and could have done 10, you had 2 in reserve (RIR 2). Most people guess within a rep or two when the set is close to failure, and further off when it is not.
What to do when you stop progressing
A plateau is when your numbers stop improving over several sessions, not after one bad day. Check the basics first: how hard you really train, how much you train, how you eat and recover. Then change one thing at a time: the rep range, the exercise, or a lighter week.
Linear progression vs double progression
Linear progression adds weight every session and keeps the reps fixed. Double progression adds reps at the same weight first, and adds weight only when every set reaches the top of the rep range. Linear works for beginners for a while, then stalls. Double progression is slower per session but lasts much longer.
What is a deload week, and when do you need one?
A deload is a short period of lighter training, usually one week, meant to ease fatigue before you build up again. Many lifters plan one every 4 to 6 weeks. You can also take one when your numbers stall or you feel worn down. You keep training, with fewer sets and more reps left in the tank.
Food 7
Protein, calories and how to spread them.
How accurate is photo logging?
Photo logging is useful, but not exact. In studies, logging from images tends to come out lower than what people really eat, mostly because portions are hard to judge from a picture. That is also true for writing food down by hand. In Mitta, the photo only suggests foods and portions; the nutrition values come from food databases, and you check every item before anything is logged.
How much protein do you need to build muscle?
If you lift weights and want to build muscle, aim for about 1.6 to 2.2 grams of protein per kilogram of body weight per day. At 80 kg that is 128 to 176 g. Below that range you may leave some gain on the table. Above it, studies find little or no extra muscle.
How your food targets are calculated
Mitta starts with the Mifflin-St Jeor formula for your resting burn, multiplies it by your daily activity and training days, and adds or takes off a fixed amount for your goal. Protein is 2.0 g per kg of body weight (2.2 when you are losing fat), fat 0.9 g per kg, and carbs fill the rest. With Pro, the target is then corrected with your own intake and weight trend.
Should you eat more on training days?
You can, but you do not have to. For building muscle or losing fat, what you eat over the whole week matters more than how it is spread. Moving some carbs from rest days to training days can make hard sessions feel better and rest days feel lighter. Keep protein the same every day.
Why your targets move with your training
With Pro, your carb target goes up by 15% on days with strength training and down on rest days, so your weekly average stays the same. Protein and fat do not change. Hard sessions get more fuel, rest days get a little less, and what you eat over the week still matches your goal. You can turn it off.
How many calories do you need to build muscle?
Eat a little more than you burn. Reviews suggest a surplus of about 10 to 20% above maintenance, with a weight gain of 0.25 to 0.5% of your body weight per week for beginners and intermediates. Experienced lifters should stay at the lower end. Start with an estimate, then let your weight trend tell you whether to eat more or less.
What a calorie floor is, and why we have one
A calorie floor is the lowest daily target Mitta will set: 1,500 kcal for men and 1,200 kcal for women and everyone else. Eating less than that without guidance makes it hard to get enough nutrients, to train well and to recover, and losing weight faster than about 1% of your body weight a week costs more muscle. Mitta also never lowers your target while you are already losing faster than that.
How Mitta decides 8
The rules behind the targets in the app.
How Mitta sets your lift target
Your lift target comes from fixed rules, not guesswork. Mitta looks at your last session with that exercise, the rep range in your plan, the smallest weight step and your experience level. Hit the top of the range on every set and the weight goes up one step. Otherwise you add a rep, and after two weak sessions in a row the weight comes down about 10%.
How we count weekly sets
Mitta counts a finished work set as 1 set for the main muscle of the exercise and half a set for each helping muscle. Warm-up sets and sets you did not finish are not counted. So 3 sets of bench press give chest 3 sets, triceps 1.5 and shoulders 1.5.
How your experience level changes your plan
Your experience level changes five things in Mitta: how many sets you start with, how close to failure you train, when the weight goes up, how long a training block runs, and how many numbers you see. Beginners get fewer sets, more reps in reserve and faster jumps in weight. You pick the level when you start, and Mitta suggests moving up when your history says you are ready.
Training with hypermobility
Strength training is part of the usual advice for people with hypermobile joints, not something to avoid. The guidelines start with control and stability, keep joints out of their end range under load, and build up slowly. If you tell Mitta you are hypermobile, it picks more machines and cables, keeps sets at 8 reps or more, leaves an extra rep in reserve and starts with a little less volume. It does not diagnose anything.
How training blocks and the lighter week work
A training block is a set of weeks where you get a little closer to failure each week, usually 4 to 6, followed by a lighter week. Mitta starts at 3 reps in reserve and works toward 1 or 2. In the light week you keep the same weight, do half the sets and stop with 3 to 4 reps in reserve. Light weeks do not count towards your next target.
How we decide what counts as evidence
Every article here carries one of four labels: Strong, Moderate, Weak or Expert opinion. The label says how much we trust the main claim, and a short note says why. The rules for the labels are our own editorial choice, not a scientific standard. We loosely follow how evidence is graded in medicine, where trials count for more than opinion and studies that disagree count for less.
Our safety limits
Mitta has a few fixed limits on food targets. A calorie floor of 1,500 kcal a day for men and 1,200 for women and everyone else. A daily target that moves at most 200 kcal per check-in, and at most once every 14 days. No lower target while you are already losing more than 1% of your body weight a week. The coach has extra rules on top. You must be 18 or older.
Why a lift target can go down
A target goes down when you miss the bottom of the rep range in two sessions in a row. Mitta then takes about 10% off the weight, rounds it to a weight step, and sets the target at the bottom of the range. The idea is to get clean reps again and build back up, instead of repeating a weight that has not worked twice.
How we rate evidence
Strong: several good studies point the same way. Moderate: good studies, but fewer of them, or with mixed results. Weak: early or limited research that could change. Expert opinion: what experienced coaches do where research is thin. How we decide what counts as evidence.
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