Begin with a few minutes of easy movement, then practice the first exercise through progressively heavier warm-up sets. Keep those sets light enough that they prepare you for the working sets without exhausting you.
Notice whether a familiar warm-up load feels unusually difficult. Record that observation if it affects your choice of working weight, and distinguish warm-ups from hard sets in the log.
What a warm-up is actually for
The claim you will see most often is that warming up prevents injury. Be careful with that one. It is plausible and widely believed, and the research behind it is not strong enough to hand you as a guarantee, so a page that sells you a warm-up as insurance is overselling.
Here is the version you can rely on: a warm-up makes the first working set feel and perform like the third one. Muscle and joint tissue behave differently a few degrees warmer, the movement pattern gets a rehearsal, and your nervous system stops treating a heavy bar as a surprise. The practical result is that your first working set stops being the throwaway set.
That is worth ten minutes on its own. If injury risk drops too, good, but you do not need that claim to justify the habit, and you should not build a training decision on it. Anything that actually hurts is a conversation with a clinician, not a warm-up problem.
The two halves of a warm-up routine
| Part | What it is | How long |
|---|---|---|
| General | Easy cardio or unloaded movement: bike, rower, brisk walk, leg swings, arm circles, bodyweight squats | 5 minutes |
| Specific | Ramp sets of the first exercise, light to just under your working weight | 3–5 minutes |
The general half is interchangeable. Pick whatever is free and get slightly out of breath; the machine you use is not a variable worth thinking about. This is also the whole warm-up if today is an easy session. The running guide covers why five minutes of brisk walking is enough before an easy run, since the first slow interval finishes the job.
The specific half is not interchangeable, and it is the half people skip. Ten minutes on a bike does very little to prepare you for a heavy squat, because it never asks your hips, knees and spine to hold that position under load. Only squatting does that.
The ramp: how many sets, and how heavy
Work up in two to four jumps, keeping reps low as the weight climbs so the ramp never becomes training in its own right. A workable default for a top set of five:
| Ramp set | Load | Reps |
|---|---|---|
| 1 | Empty bar or ~40% of the top set | 5–8 |
| 2 | ~60% | 5 |
| 3 | ~80% | 3 |
| 4 (heavy days only) | ~90% | 1 |
Those numbers are a common coaching starting point rather than a precise prescription: adjust the number of jumps to the load. A 95 lb squat needs two ramp sets; a 405 lb squat needs five. Two rules generalize better than the percentages: the jumps get smaller as the weight gets heavier, and the reps come down as the load goes up, so you arrive fresh rather than pre-fatigued.
You only need the full ramp for the first exercise of a session. Once you are warm, the second and third movements need a single lighter set at most, and accessories usually need nothing. The busy schedule guide makes the same point from the other direction: general warm-up filler is the first thing to cut when you are short on time, and the ramp sets are the last.
Should I stretch before lifting?
Not the way most people mean it. Long static holds (sitting in a stretch for 30 seconds or more) are best saved for after training or for their own session. Held long enough, they can leave a muscle transiently weaker, which is the opposite of what you want two minutes before a heavy set.
Move instead. Dynamic stretching before a workout means taking the joints you are about to load through their range under control: leg swings, hip circles, bodyweight squats to depth, band pull-aparts before pressing. Ten reps of each, no holding.
The exception is a position you cannot reach at all. If your ankles will not let you squat to depth, a targeted stretch or a mobility drill before the session is a reasonable trade. The squat guide covers ankle mobility as one of the four faults that show up under load. General flexibility work still belongs in its own slot, where it is not competing with a top set.
How long should a warm-up be?
Ten minutes covers most sessions: five general, five specific. Push it to fifteen if the weather is cold, you sat at a desk all day, you are over 40, or today's top set is genuinely heavy. Pull it back to five if you are doing light accessory work or a session that starts easy anyway.
What should not happen is a warm-up long enough to become a workout. If you are spending twenty-five minutes on activation drills before touching a bar, that time is coming out of the training that actually drives the result, and the sets per week guide is about the sets that count, not the ones that precede them.
The ramp is a measurement, not a formality
By the time you finish your last ramp set, you already know what kind of day this is. The 80% set that normally moves like a warm-up feels like real work, or it flies up faster than it did last week. That is information about today (your sleep, your food, the week's accumulated fatigue) and it arrives before you have committed to a number.
Most people notice it and then ignore it, because there is nowhere to put it. Rating it fixes that. If you use RPE, your last ramp set has an honest rating like any other set: a 3 when things are normal, a 6 when they are not. A ramp set two full points harder than usual is the clearest early signal you will get that today's top set should come down.
ChatRPE can act on that in the moment, because the ramp and the working sets are in the same conversation:
"Ramped up to 225 for 3 on squats, felt like an RPE 6: normally that's a 3 or 4. Top set was supposed to be 275 for 5. What should I actually do?"
And it can act on it across weeks, because you can say the whole thing in one message afterwards and it becomes structured entries: exercise names, each set's weight and reps, and the effort you reported on each. The workout log guide covers that plain-language path, and between sets you can say it out loud instead of typing, which the hands-free guide covers.
One detail that keeps the log honest: name your ramp sets as warm-ups when you log them. They belong in your history as evidence about how you felt, and they do not belong in your weekly hard-set count. A hard set is one taken close to failure, which a ramp never is. Keeping the two distinguishable is what lets you ask for a working-set count later without your warm-ups inflating it.
"Squat day, top set is 275 for 5. Walk me through a warm-up: five minutes easy, then ramp sets up to my working weight. Log the ramp separately from my working sets, and after the last ramp set I'll tell you how it felt so you can pick the top set."
Run the warm-up as a live session
Ask ChatRPE to run a warm-up as a live session with an ordered list of drills and timers. The guided workout guide explains how to advance the steps and use iPhone timer alerts.
On iOS the start phrase carries the kind of session with it, so a stretching or mobility session opens straight from Siri without unlocking the phone. And a warm-up run this way archives itself into your history like any other session, so "how often do I actually do the mobility work I keep saying I'll do" becomes a question with an answer.
Track what skipping it costs you
You do not have to take any of this on faith, including the parts of it that are general coaching advice rather than facts about you.
Pick one number that reflects how the session went (how the first working set felt, or your rating on a matched top set) and log a note when you skipped the warm-up. Over a couple of months, ask for those two things on one chart. ChatRPE can put two saved metrics on a single view, on separate axes when their scales differ, so "rushed warm-ups" and "first-set RPE" can sit side by side. The custom data tracking guide covers inventing a metric like that from nothing.
Two caveats so you read the result properly. This is your own n of one, so a pattern is a reason to keep doing something rather than proof of a mechanism. And the coach's numeric summaries run over a recent window of entries rather than your entire archive, with any reported trend being a first-half-versus-second-half comparison rather than a statistical test: name a date range when you are looking back months, and let the chart settle it.
From a ritual you skip to a ramp that tells you something
A warm-up gives you information before you commit to the working load. Keep a note when it changes that decision.
Frequently asked questions
How do I warm up before a workout?
Five minutes of easy general movement to raise your temperature and loosen up, then two to four ramp sets of the first exercise you are about to do: light, then moderate, then just under your working weight, with reps dropping as the load rises. Roughly ten minutes in total. Later exercises in the same session need one lighter set at most.
What is a good warm-up routine before lifting weights?
Bike, row, or walk briskly for five minutes, then do movement drills for the joints you are about to load: leg swings and bodyweight squats before squatting, band pull-aparts and light presses before benching. Then ramp the first lift in two to four jumps. Keep the whole thing under fifteen minutes.
Should I stretch before lifting or after?
After, mostly. Long static holds before a heavy set can leave a muscle transiently weaker, so save them for the end of the session or a separate slot. Before lifting, stretch dynamically: controlled movement through the range you are about to use, without holding anything. A short targeted stretch is still fair game for a position you genuinely cannot reach.
How long should a warm-up be?
About ten minutes for a normal session, up to fifteen when it is cold, you have been sitting all day, or the top set is heavy. Five is enough for light accessory work. If your warm-up regularly runs past twenty-five minutes it has stopped being preparation and started competing with the training.
Does warming up prevent injury?
The evidence is not strong enough to promise that, and anyone who tells you otherwise is going beyond what is known. What a warm-up reliably does is make your first working set feel and perform better, which is a good enough reason on its own. Persistent pain is a clinician's question, not a warm-up's.
Do warm-up sets count toward my weekly volume?
No. A hard set means one taken close to failure, and a ramp set is deliberately nowhere near it. Log them anyway (they tell you how the day was going) but keep them labelled as warm-ups so your working-set count stays clean.
Can an app tell me how to warm up for today's session?
That is the useful version of the question, and it needs your history to answer. ChatRPE builds the ramp from the working weight you are actually about to lift, walks you through it as a live session if you want, and takes your rating on the last ramp set into account when it picks the top set. Meet ChatRPE and let the warm-up start earning its ten minutes.