Learn out-of-the-saddle pedalling: when standing on a road bike pays off, what it costs (about 12 % more oxygen) and 5 steps to rock the bike smoothly.
The honest answer: out-of-the-saddle pedalling is not a trick for more efficiency but a tool for short, hard spots. Standing, you burn more energy than sitting at the same speed. Ten cyclists rode a 4 percent gradient on a treadmill at 19.3 kilometres per hour. Standing, their oxygen uptake was 31.7 millilitres per kilogram per minute, seated 28.3 [1]. That is about 12 percent more, a noticeable surcharge you pay for getting a bit more pressure onto the pedal for a short time.
Interesting: at higher intensity this difference shrinks. A study with ten riders at 50 and 70 percent of maximal aerobic power showed that economy remained worse when standing, but the gap got smaller at higher intensity [2]. A third study with 13 elite-level riders even found no significant difference in energy cost, but 4.3 percent higher mechanical cost when standing because the bike sways and rolling resistance rises [3].
Standing is more expensive, but not as expensive as many think. And it pays off when it is used briefly and on purpose.
Bottom line: if you master out-of-the-saddle pedalling, you use it for steep ramps, the acceleration after a corner and short relief for your backside. Realistically it takes some weeks until you can let the bike rock calmly beneath you (experience value).
Before standing up, shift one or two gears harder. Standing you lack the support of the saddle, and a gear that is too easy lets the crank spin through. Hold the hoods or tops loosely and keep your elbows slightly bent.
Milestone (practice): you shift before standing up, not only once you are standing.
Stand on the pedal on the downstroke and lift your backside about a hand's width above the saddle. Your centre of mass moves slightly forward.
In out-of-the-saddle pedalling the bike tilts slightly to the side of the pushing foot in the rhythm of the strokes, while your body stays calm above it. Letting the bike swing strongly sideways wastes energy: mechanical cost rose by 4.3 percent when standing, mainly through bike sway and higher rolling resistance [3]. The goal is a small, calm rocking.
Milestone (practice): 30 seconds out of the saddle on a climb with torso and handlebars staying calm.
Sit back down on the downstroke at the end of the section and then shift one gear easier. Only then does cadence not collapse. Switch between sitting and standing deliberately rather than leaving it to chance.
Use it on steep ramps, for the acceleration after a corner and for short relief. Because the difference shrinks at higher intensity [2], it pays off mostly when it gets hard.
Milestone (practice): 3 climbs in a row where you alternate sitting and standing without your speed collapsing.
When standing, the centre of mass moves forward [3] and the rear wheel is loaded less. On wet or loose surfaces it spins sooner. Stay in the saddle there. Before every ride check that pedals, chain and gears run tight and clean, because a chain breaking while standing can throw you forward abruptly.
I found no reliable study on out-of-the-saddle pedalling and knee pain. All that is known is that patellofemoral syndrome, pain at the kneecap, is the most common overuse diagnosis in road cycling [4]. If your knee hurts when standing, stay seated and have your position checked. This guide explains and motivates, it does not replace supervised training or medical assessment.
Try the "pendulum check": ride 30 seconds out of the saddle and watch the front tyre. If it moves more than a hand's width sideways, your bike is rocking too much. Imagine pushing the pedals down and letting the bike hang beneath you like a pendulum rather than actively pulling it to the side.
No. Standing, riders used about 12 percent more oxygen than seated at the same speed on a climb [1]. The difference gets smaller at higher intensity [2]; a study on elite riders found it not significant but found higher mechanical cost [3]. Out-of-the-saddle pedalling is a tool, not an efficiency gain.
On short, steep ramps, for the acceleration after a corner or for brief relief. Since the surcharge shrinks at higher intensity [2], it makes most sense when it gets hard anyway. That is the conclusion from the studies, not a fixed rule.
Usually one to two gears harder than seated. A gear that is too easy lets the crank spin through. This is practice standard; there is no fixed measured value for it.
Some rocking is normal. Movements that are too large raise rolling resistance and mechanical cost, 4.3 percent more in elite riders [3]. Keep your torso calm and your arms loose.
Sprinting on a Road Bike: Position, Gear and Timing for Maximum Acceleration