A warm-up before lifting has two parts: general movement to raise your heart rate and loosen you up, then specific warm-up sets to prepare your body for the weight you're about to move. The whole thing takes 10-15 minutes.
Most beginners skip it or rush it. Both make your first working set feel worse than it should.
why warming up matters
Your first working set of the day is asking a lot of your body. Your core temperature is lower than it will be mid-session. Your joints haven't been taken through a full range of motion. Your nervous system hasn't rehearsed the movement pattern you're about to load.
A warm-up addresses all three. Body temperature rises. Joints move through their full range. Your nervous system runs through the motor pattern before the weight gets heavy.
The payoff is practical: your first set starts cleanly. You feel the difference in the first rep. The warm-up also gives you a read on the day. Some sessions you walk in sharp. Some days everything feels heavy from the start. The warm-up tells you which kind of day it is, before the stakes are high.
the two parts of a warm-up
general warm-up (5 minutes)
This part gets your heart rate up, your blood moving, and your body temperature rising. Five minutes on a treadmill at a slow jog, a stationary bike, or a brisk walk does the job.
The target is warm: maybe slightly flushed, breathing a little harder than normal. Five minutes is enough.
If you'd rather skip the cardio machine, dynamic movement works just as well:
- Arm circles (10 each direction)
- Hip circles (10 each direction)
- Leg swings front-to-back (10 each leg)
- Lateral leg swings (10 each leg)
- Bodyweight squats (10-15 reps)
- Inchworms (5)
Pick whichever you'll actually do. Both accomplish the same thing.
specific warm-up sets
This is the more important part. Before your first heavy exercise, you do several sets at progressively higher weights, working up to your actual training weight.
Here's an example for someone squatting 135 lb for 3 sets of 5:
- Empty barbell (45 lb): 5-8 reps, very easy
- 75 lb: 5 reps
- 105 lb: 3 reps
- Working sets at 135 lb: 3×5
And here's an example for someone bench pressing 95 lb for 3 sets of 8:
- Empty barbell (45 lb): 5-8 reps
- 65 lb: 5 reps
- 80 lb: 3 reps
- Working sets at 95 lb: 3×8
Each warm-up set prepares you for the next one. By the time you reach your working weight, the load should feel like the next step in a sequence.
Start with the empty barbell even if it feels absurdly light. It's your best opportunity to check your form, your bar path, and your setup before the weight makes any problems harder to correct.
how many warm-up sets you need
How many sets you need scales with how heavy you're going.
- Up to 100 lb working weight: 1-2 warm-up sets
- 100-200 lb: 2-3 warm-up sets
- Above 200 lb: 3-4 warm-up sets
Keep reps low as the weight climbs. At 80-90% of your working weight, one or two reps is enough. The goal is activation. Keep warm-up volume small so your working sets still feel fresh.
Bar speed is a useful signal during warm-up sets. If the bar is moving slowly and you're grinding even at 70% of your working weight, you may need an extra set or two before loading up. If it's moving fast and crisp, you're ready.
Rest between warm-up sets can be short: 60-90 seconds. Use the time to load the next weight and settle before the next set.
do you warm up for every exercise
Only for the first exercise in each muscle group.
If your session opens with squats, warm up for squats. If leg press comes next, your legs are already warm. One ramp-up covers the session for that muscle group.
Same logic applies across every group. If you train push/pull/legs, warm up for the first pressing movement on push day, the first pulling movement on pull day, the first leg exercise on leg day. Everything else in the session benefits from that same heat.
One exception: if you take a long break mid-session, maybe 20 minutes or more, your muscles will cool down. In that case, a few light sets before your next exercise are worth doing.
stretching before you lift
Dynamic stretching is useful before a session. Long static holds are better saved for after.
Dynamic stretching means moving through a range of motion: leg swings, hip circles, shoulder rolls, arm swings. These take your joints through the ranges they'll need during your session. A few minutes of dynamic movement works well as your general warm-up, or on top of it.
Static holds (a 30-second hip flexor stretch, a held quad stretch) are more effective after your session, when your muscles are warm and pliable. Holding a stretch before heavy lifts can temporarily reduce force output in the stretched muscle, with the largest drop in performance when the hold runs longer than 45 seconds. Save them for the end.
what to do when you're short on time
Do the specific warm-up sets and skip the general warm-up.
The specific warm-up is what directly prepares your joints and nervous system for the exercise you're about to do. The general warm-up supports it, but when time is short, the specific sets matter more.
If you're still working out your session structure and don't know which exercise to start with, here's a guide to getting your first workout in order. The warm-up becomes obvious once you have that framework.
what to log
Log your working sets. Warm-up sets are preparation. Track your working sets only.
Your working sets are the ones at your actual training weight, doing the reps your program calls for. Those drive your progress over time. Arc tracks every working set so when you come back next session, you know exactly where you left off and what comes next. The warm-up gets you there.
Sources
- Simic, L., Sarabon, N. & Markovic, G. (2013). Does pre-exercise static stretching inhibit maximal muscular performance? A meta-analytical review. Scandinavian Journal of Medicine & Science in Sports, 23(2), 131-148. pubmed.ncbi.nlm.nih.gov/22316148
know exactly what you're warming up for
Arc builds your training plan and logs every working set. You walk in with a plan and leave knowing exactly where you stand.
