Reps in reserve, double progression, trend weight, basal metabolic rate. These are the words behind your plan in Coach Timon. Here's what each one means, why it matters and what the app does with it, in plain language.
Open a training program or a nutrition plan and you get a wall of jargon. RIR 2. Rep range 8 to 10. Trend weight. Maintenance. Most people nod and skip it.
Each of those words stands for a decision in your plan, though. Once you know them, you see why your plan changed this week. They're grouped in the order you meet them: training first, then the scale, then nutrition, then the weekly check-in that ties it together. Want the bigger picture of why the app exists? I wrote that down in why another app.
RIR is how many more clean reps you could have done at the end of a set. RIR 0 means nothing left. RIR 2 means you had two more in you.
How hard a set is decides a lot of what it does. Across a series of meta-regressions, strength gains were similar over a wide range of RIR, while muscle growth improved as sets ended closer to failure. Going all the way to failure doesn't seem to add much, though: a meta-analysis of 15 studies found no clear extra growth from training to momentary failure compared with stopping just short of it. A few reps in reserve is a sensible place to train.
Most people's guesses land pretty close. In a review of 12 studies, people underestimated the reps they had left by about one on average, with big differences between studies.
In the app you log the weight, the reps and your RIR for every set. Each exercise has a target RIR, and the program uses what you log to set your weights for the next week.
Source: Robinson et al.1 2024, Sports Medicine · Refalo et al.2 2023, Sports Medicine · Halperin et al.3 2022, Sports Medicine
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A rep range is the window of reps you aim for on an exercise, for example 8 to 10. Every number inside it counts as a good set.
A range gives you room. Some days 10 reps fly, some days you stop at 8. Both are fine, and both tell the system something.
In the app every exercise has a rep range, paired with your target RIR.
Progressive overload means asking a little more of your muscles over time: more weight, more reps or more sets. Do the same workout at the same weight forever and your body has little reason to keep adapting.
You can progress by adding weight or by adding reps. In an 8-week lower-body trial with 43 trained people, both routes gave similar results for muscle growth and strength.
Double progression combines the two. You add reps first, inside your rep range. Once you hit the top of the range, the weight goes up and you work your way up from lower in the range again.
In the app: hit the top of your rep range at your target RIR and the weight goes up the following week. Say you bench 60 kilos for 10 reps at your target RIR. Next week the system sets 62.5 kilos for 8.
Source: Plotkin et al.4 2022, PeerJ
Warm-up sets are lighter sets before your working sets. They get your body and your technique ready for the heavy work.
A systematic review of 31 trials on upper-body warm-ups found strong evidence that warm-ups with heavier, dynamic loads improve power and strength. In a trial with 40 trained men, a few light reps weren't enough to get the best out of the squat and the bench press. How much warm-up you need is less clear, and the studies don't all agree.
In the app every session has a warm-up built in, with videos that show you how to warm up properly. Your warm-up sets are calculated every week from the weights you lifted the week before.
Source: McCrary et al.5 2015, British Journal of Sports Medicine · Ribeiro et al.6 2020, International Journal of Environmental Research and Public Health
Your split is how you divide your training over the week, for example full body every session or upper and lower body on separate days. Tempo is the speed of each rep. Rest time is how long you sit between sets.
In the app you choose your preferred split in the intake, together with how many days you train, how long a session can last and up to two muscle groups to focus on. Every exercise has a demo video with its tempo and rest time, plus a ready-made alternative in case a machine is busy or a movement doesn't work for you yet.
A deload is a planned period of reduced training stress. An international panel of coaches defined it as a way to reduce physical and mental fatigue, help recovery and get you ready for the next block. In a survey of 246 strength and physique athletes, they deloaded for about six days, roughly every five to six weeks, mostly by lowering volume, load and effort.
A deload means training lighter. What about a full week off? In a trial with 39 trained people, a week without any training halfway through a 9-week program gave no extra muscle growth and smaller strength gains in the lower body.
In the app the system plans a deload week automatically: when your recovery scores stay low, or at the end of a training block.
Source: Bell et al.7 2023, Sports Medicine Open · Rogerson et al.8 2024, Sports Medicine Open · Coleman et al.9 2024, PeerJ
Recovery is how ready you are to train hard again. Sleep is a big part of it. Across 69 studies, losing sleep lowered physical performance by about 7.5 percent on average.
In the app sleep is part of your weekly check-in and of how the system reads your recovery. The check-in also asks about your stress. Your steps and sleep come from your watch, ring or other wearable. Poor recovery changes your training week.
Source: Craven et al.10 2022, Sports Medicine
Your trend weight is a smoothed average of your weigh-ins. It shows where your weight is heading without the day-to-day noise.
Water, salt, carbohydrates and a short night move the scale from one morning to the next. In a European study with more than 1,400 people who were maintaining weight loss, weight swung by about 0.35 percent within a normal week, up at the weekend and down during the week. Regular weighing has been linked to better weight management and not to more depression or anxiety.
In the app your trend weight is calculated every night, so one salty dinner never moves your plan. Weighing in each morning is optional and highly recommended: the more often you weigh in, the more reliable your trend.
Source: Turicchi et al.11 2020, PLOS ONE · Zheng et al.12 2015, Obesity
Your basal metabolic rate is the energy your body burns at complete rest, just to keep you running. For most people it's the largest part of what you burn in a day.
BMR is usually estimated with a formula from your weight, height, age and sex. The Mifflin-St Jeor formula is the most likely to land within 10 percent of a measured value, although it can still be off for an individual.
In the app your calorie targets never go below your basal metabolic rate.
Source: Mifflin et al.13 1990, American Journal of Clinical Nutrition · Frankenfield et al.14 2005, Journal of the American Dietetic Association
Your total daily energy expenditure, or TDEE, is everything you burn in a day: your BMR, the energy it takes to digest your food and everything you do when you move, from training to walking to the shop.
That number moves when your body changes. In a classic study, people who kept their weight at least 10 percent lower burned about 6 to 8 kilocalories less per kilo of lean mass per day than before. That's one reason a formula based on your starting point drifts over time.
In the app the system estimates what you really burn from your food log and your trend weight.
Source: Leibel et al.15 1995, New England Journal of Medicine
Maintenance is the number of calories at which your weight stays stable. Eat above it and your weight goes up over time, eat below it and it goes down.
In the app your targets follow your trend in small steps. On the app page you can see an example: the trend stays flat for seven days, so the daily target drops by 100 kilocalories, from 2,150 to 2,050.
Macros are the three nutrients that carry calories: protein, carbohydrates and fat. Your macro split is how your calories are divided over the three.
In a meta-analysis of 49 trials, extra protein added lean mass and strength on top of training. For lean mass, the benefit leveled off at a total intake of about 1.6 grams per kilo of body weight per day.
In the app your plan is built on macros: daily targets for calories, protein, carbohydrates and fat. You choose your diet type and your macro split, or let the system do it. Logging is quick: scan a barcode, snap a photo of your plate or copy yesterday's meal.
Source: Morton et al.16 2018, British Journal of Sports Medicine
A diet break is a planned stretch, often one or two weeks, where you eat at maintenance in the middle of a longer diet.
In a trial with 61 trained adults and 12 weeks of dieting, people who took a one-week break after every three weeks (15 weeks in total) lost the same amount of fat and kept the same amount of lean mass as people who dieted straight through. They reported less hunger. In an earlier trial with men with obesity, two-week breaks led to more weight loss, although that diet took 30 weeks in total against 16.
In the app: during a longer stretch of fat loss, the app plans a diet break automatically. Your calories then go to maintenance for a while.
Source: Peos et al.17 2021, Medicine & Science in Sports & Exercise · Byrne et al.18 2018, International Journal of Obesity
Satiety is how full you feel after you eat, and how long that lasts.
In the app you can add a note to a meal and how full you felt afterwards, so hunger becomes data too.
A check-in is a short weekly moment where you report how your week went. Keeping track of your own behavior helps. Across 122 evaluations of healthy eating and activity programs, self-monitoring explained more of the differences in results than any other technique, and it worked best combined with goals and feedback.
In the app you fill in a short check-in once a week: how many days you followed the plan, how you slept, your stress and your recovery. The system reads it together with everything you logged and sets up your next week. If you followed the plan on fewer than five days, your targets stay where they are, and your weekly summary shows what will help you get back on track. That summary lands in the app and in your inbox.
Source: Michie et al.19 2009, Health Psychology
| Term | In one line | What the app does with it |
|---|---|---|
| RIR | Reps you had left at the end of a set | You log it with every set; it sets next week's weights |
| Rep range | The window of reps you aim for | Every exercise has one, paired with a target RIR |
| Double progression | First more reps, then more weight | Top of the range at target RIR: weight goes up next week |
| Deload | A planned lighter stretch of training | A deload week when recovery stays low or at the end of a block |
| Trend weight | Smoothed average of your weigh-ins | Calculated every night; your calories follow it |
| BMR | What you burn at complete rest | Your targets never go below it |
| TDEE | Everything you burn in a day | Estimated from your food log and your trend |
| Macros | Protein, carbohydrates and fat | Daily targets for each, plus calories |
| Check-in | Short weekly report on your week | Read with your log to set up next week |
RIR stands for reps in reserve: how many more clean reps you could have done at the end of a set. RIR 0 means nothing left, RIR 2 means two more. In a review of 12 studies, people underestimated the reps they had left by about one on average.
You add reps inside your rep range first. Once you reach the top of the range, the weight goes up and you start again lower in the range. In Coach Timon: top of the range at your target RIR means more weight the following week.
A smoothed average of your daily weigh-ins. It shows where your weight is heading without the day-to-day swings from water, salt, carbohydrates and sleep.
BMR is what your body burns at complete rest. TDEE is everything you burn in a day: your BMR plus digesting food plus all movement. For most people, resting expenditure is the largest part.
A period of reduced training stress, usually about a week, to manage fatigue and recover before the next block. In Coach Timon the system plans a lighter week when your recovery scores stay low.
A planned stretch at maintenance calories in the middle of a longer diet. In a trial with trained adults, diet breaks gave the same fat loss and lean mass retention as dieting straight through, with less hunger. The app can plan one during a longer stretch of fat loss.
Yes. The app plans a deload week when your recovery scores stay low or at the end of a training block. During a longer stretch of fat loss it plans a diet break, and your calories go to maintenance for a while.
Timon offers High Performance 1:1 Health Coaching, wherever you live. Coaching clients can also train with him in person in Ghent, Belgium.
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Every number in this article was checked against the original publication.
This article is information, not medical advice. If you have symptoms, are pregnant or take medication, talk to your doctor before changing anything.
I'm a High Performance Health Coach in Ghent and I built an app. Coach Timon runs on the same rules I use with my one-on-one clients and adjusts your training, nutrition, lifestyle and sleep to your own data every week. This is why I built it, who it's for and what it costs.
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During the first three to four weeks, much of what you measure may be swelling. According to a researchers' model, real muscle growth starts after about eighteen sessions. After a few months, controlled studies land on average at a little under a kilo of extra lean mass, with huge differences between people.
Read the articleYou log, the app reads your trend and moves your targets every week. Training, nutrition, lifestyle and sleep in one plan. On the waiting list you hear first when it opens.
