The warm-up that works, and how long it takes

A warm-up before lifting is three parts, and none of them is stretching. Three to five minutes of light cardio, the day's dynamic movements, then three ramp-up sets on the day's first heavy lift, climbing from 40 percent to 80 percent of the working weight. Run back to back it takes five to eight minutes depending on the day, and it ends with a working set that is the first hard work you have done all day, not the second.

What should a warm-up before lifting actually consist of?

Three steps in a fixed order: light cardio to raise your temperature, dynamic movement to prime the joints and muscles about to get loaded, and ramp-up sets that build to your working weight on the first heavy lift only. Nothing in it should feel like training. By the time you touch the first working set, the warm-up's job is done.

The ramp-up percentages are the same on every day. Here is what they come out to for a lifter whose working squat is 225 lb:

The next set after that is the working set at 225 lb, at the day's actual target reps. It is the first set of the day that is genuinely hard.

Why start with light cardio?

Light cardio comes first because a warmer muscle produces more force, faster. Raising muscle temperature speeds up nerve conduction and the chemical reactions inside the muscle fiber, and for short-duration efforts that translates directly into output: a review of the thermal effects on the neuromuscular system found that a 1°C rise in muscle temperature improves short-duration force production by roughly 2 to 5 percent (Racinais and Oksa, 2010). A systematic review of 32 controlled warm-up studies found active warm-ups, of the kind that raise temperature rather than just stretch, improved subsequent performance in 79 percent of the outcomes measured (Fradkin, Zazryn, and Smoliga, 2010).

Three to five minutes is enough because the goal is temperature, not fatigue. Muscle temperature rises quickly with continuous, easy movement on a bike, a rower, or a jump rope, and it plateaus well before you have broken a real sweat. Past that point, more cardio is not warming you up any further. It is just spending reps and minutes you would rather have on the bar.

Why dynamic movement instead of static stretching?

Dynamic movement, not a held stretch, is what belongs immediately before lifting, because static stretching has a measurable, duration-dependent cost to the force you can produce right after it. A systematic review of studies on acute static stretching found little to no drop in maximal strength for holds under roughly 30 to 45 seconds, but the odds of a real strength deficit rise sharply once a single hold passes about 60 seconds (Kay and Blazevich, 2012). A separate review of the acute effects of stretching found static holds kept under about 90 seconds total, short of the point of discomfort, produced little to no impairment, while dynamic stretching before a lift showed no negative effect on performance and sometimes improved it (Behm and Chaouachi, 2011).

The effect is real, it is modest at ordinary hold lengths, and it is entirely a matter of duration. A quick 10-second stretch to check a joint is not the same exposure as a 60-second hold, and the research says so explicitly. But there is no reason to spend that budget before a lift when dynamic movement carries none of the risk and does the same job of raising readiness.

The dynamic movements are specific to the day, not a generic list:

• Pull day: arm circles, band pull-aparts, scap pull-ups.
• Push day: arm circles, band pull-aparts, scap push-ups.
• Legs day: leg swings, bodyweight squats, walking lunges, ankle rocks.
• Auxiliary day: cat-cow, dead bugs, band pull-aparts.

Static stretching still has a place in training. It just is not this one. Compound runs about ten minutes of mobility work, static holds included, after every session instead of before it. See mobility after lifting for why the order matters and what each day's cooldown targets.

Why ramp-up sets, and why 40/60/80 percent?

Ramp-up sets exist to rehearse the movement pattern under progressively real load, not to raise your temperature. Temperature is already handled by the cardio and the dynamic work by the time you reach them. Instead they tell you, that day, what the bar is actually going to feel like before it counts.

40 percent for 8 reps grooves the bar path with almost no load. 60 percent for 5 is enough weight to tell you whether the lift feels normal, heavy, or off. 80 percent for 3 is the last rehearsal before the weight gets real, and then the ramp stops. It does not climb to 90 or 100 percent, because that would just be another working set wearing a warm-up's name. The set that follows, at full working weight, is the first working set: the first hard work of the day. For how that working weight gets decided session to session, see double progression.

Why does only the first lift get ramped?

Only a day's opening lift gets ramp-up sets because by the second exercise, you are already warm. The pattern practice and the temperature work were both spent on the first lift, and nothing about the second exercise needs them repeated.

The code enforces this directly: ramp-up sets are generated only for the day's first lift, and only when that lift is rep-based and uses weight. A carry has no rep pattern to groove, since it is measured by distance, and no percentage of a working weight to climb toward, so the whole ramp-up step drops off the day it opens. On a day like that, the warm-up is two steps, cardio and dynamic movement, and takes about five minutes. On a day that opens with a rep-based barbell lift, the warm-up is three steps and takes about eight.

Does warming up prevent injury?

Probably a little, but the evidence is thinner than most fitness advice implies, so treat injury prevention as a possible bonus rather than the reason to warm up. A review of randomized controlled trials on warming up and injury concluded there was insufficient evidence to either endorse or discontinue routine warm-up as an injury-prevention strategy, though the trend in the data favored a reduced risk (Fradkin, Gabbe, and Cameron, 2006). Nobody has run the trial that proves it either way for resistance training specifically.

A warm-up reliably raises force output, improves readiness, and lets you rehearse the pattern before it matters, which is exactly what the temperature and stretching research measures. That is worth doing on its own merits. Promising it will keep you from getting hurt is a claim the research has not made yet.

What does Compound do about warm-ups?

Compound builds this exact sequence into every session, timed to the day. It reads your current working weight for the day's opening lift and computes the 40/60/80 percent ramp automatically, rounded to a plate you can actually load, 5 lb or 2.5 kg, so there is no percentage math to do standing at a barbell. The dynamic movement list is specific to the day, matched to the muscles about to get worked, not a generic stretch list.

Warm-up is on by default and can be turned off entirely in settings if it is not for you. Mid-session, a skip-cardio button ends the cardio segment on the spot, and a skip-to-lifts button jumps straight to the first lift from wherever you are, skipping whatever dynamic movement or ramp-up sets you have not gotten to yet. A warm-up that adds friction on a bad day is worse than no warm-up at all.