What is vertical oscillation?
In running, vertical oscillation, or VO for short, is the distance the centre of body mass travels vertically (up and down) at each stride. The downwards VO is equal to and is a consequence of the upwards VO.
Is vertical oscillation good or bad?
Excessive VO is bad for sure however zero VO is also a sign of inefficient running technique, meaning you are probably reaching ahead of your body (with your landing foot) to avoid falling, probably touching down with heel first.
All I can say is, to minimise or optimise vertical oscillation you must correct your running technique.
How bad is excessive vertical oscillation?
Over a long course of running, it is like climbing up a tall building in addition to running your running course.
For instance, if you run a [full] marathon (42.2km or 26 miles) in 4 hours at average cadence of 180 strides per minute, and you only have 1cm (0.393 inch) excessive VO, the total vertical distance you excessively climb up during the race is:
4 (hours) x 60 (minutes) * 180 (spm) * 0.01 (meter) = 432 meters or 1417.32 feet or 472.44 yards
It is pretty much like climbing up Steinway Tower in New York City as well as running your marathon race.
Which phase of VO is more expensive, upwards or downwards?
Of course upwards because going against the gravity is more costly.
The [vertical] length of the downward phase is equal to and actually the consequence of the upwards one. When it is higher than what it should be, the runner has to deal with a greater force at landing due to falling from a higher height. It may not sound concerning at first, especially because the deviation from the optimum amount is about a centimetre or two, but the longer the running course the higher wasted energy and the higher chance of injury. That is why excessive VO is bad. It hurts both ways, up and down.
Does running cadence (strides per minute) affect vertical oscillation?
It does but it is a crucial point to understand that cadence is a by-product of running, not something to be actively involved with. For instance, the golden 180 spm might be achieved while there is still an excessive vertical oscillation.
How to optimise or minimise vertical oscillation in running?
Correct running technique is the solution for minimising vertical oscillation. Excessive vertical oscillation is caused by excessive movements during each running stride, mainly by pushing off the ground which is very common amongst runners. Apart from recreational runners, there are even some elite runners who push off the ground without knowing about the inefficiency of doing so.
There are inefficient running techniques in which VO is minimised. For instance, reaching ahead of the body minimises vertical oscillation but it causes more issues:
- Reaching ahead (over-striding + landing ahead of the body) exerts excessive pressure on knees and other body parts (some physiotherapists relate ITBS to over-striding).
- By not landing under the body (or close to the vertical line passing the centre of body mass), the runner does not benefit from elasticity of tendons by preserving the energy in them during landing. This energy is released in the next stride when we need to adjust our height to fall again, simply meaning saving energy or the so called efficiency.
How is vertical oscillation handled in Pose running?
As far as pushing off the ground, active landing, and over-striding are eliminated in Pose Method of Running, vertical oscillation is down to its minimal possible range, which is mostly based on the range of stretch of some tendons in our legs.
In Pose method, falling forward is the only source of propulsion. To be able to fall again after landing, we have to go back to the same height. Adjusting height is done unconsciously. A portion of this height adjustment is done by the release of energy preserved in our leg tendons. This simply means efficiency.