The B-skip in running drills: after the knee lift, extend the leg explosively forward, then pull it actively back under the body. Build-up, mistakes and safety.
The honest answer up front: the B-skip is an A-skip where, after the knee lift, you extend the leg explosively forward and then pull it actively back under the body. That is how the running-drill collection of the Swiss Federal Office of Sport (BASPO) with Swiss Athletics describes it: in the B-skip the leg is extended explosively forward after the knee lift, "like a B" [1]. In plain words: first knee up, then throw the leg forward, then pull the foot back under you as if with a rope.
What is it for? The source names an economical, energy-saving running technique and coordination as the goal [1]. The pull-back, the "pawing", connects to the pull run, which trains active push-off and the posterior chain of calf, hamstring and glutes [4]. Does the B-skip make you measurably faster? There is no study on that. Research supports the principle behind the pull-back indirectly, though: in a study of 14 runners, braking forces rose when the foot landed farther in front of the hip [5]. The foot should not be "placed" forward but pulled actively back under the body [3].
Who is the B-skip for? For runners who master the A-skip securely and want to train coordination further. If you still wobble in skipping, stay there: a clean A-skip brings you more than a half B-skip. BASPO advises starting with simple exercises and building hard ones slowly anyway [2].
How hard is it? The B-skip is more demanding than the A-skip. In experience terms you need several weeks. The names of the skip family are interpreted slightly differently by coaches; here the BASPO description applies.
Start with a few A-skips so the rhythm of two hops and tap sits [1]. Milestone: 20 meters of A-skip without a rhythm break.
After the knee lift you extend the lower leg forward [1]. The extension is explosive, but the knee does not slam through hard (practice hint). The torso stays upright.
From the extension you pull the foot actively backward under the body [4]. The foot lands under the body [3]. This is the pawing movement: you "scrape" the ground toward you.
As in the A-skip you hop twice on the stance leg while the other leg does the cycle [1]. Breathe evenly.
20 to 30 meters, then jog back easily, 2 to 3 repetitions [2]. Milestone: 3 clean passes without losing pace or posture.
Film yourself from the side and count how many passes you manage before the pull-back fades. If you leave the foot in front already on the second pass, that is your signal to shorten the distance. Running drills may also come at the end of a session to train clean technique when tired [2], but only if you master the exercise securely. After each session, write down in one sentence what felt better than last time. That makes progress visible when your time does not change at once.
A skip with two hops on one leg in which the other leg is extended explosively forward after the knee lift [1].
In the A-skip the knee angle stays tight, in the B-skip the leg is extended forward [1].
It trains active push-off and the posterior chain [4]. The foot should land under the body [3].
BASPO advises 10 to 20 minutes of running drills per session, 20 to 30 meters per exercise, 2 to 3 repetitions [2]. Do not add too many exercises at once.
Power Skip (Hopserlauf): A Strong Push-Off in a Tam-Da-Tam Rhythm