Lifting your feet higher costs LESS energy when running

Summary

This video script addresses a common misconception in running technique: that lifting feet higher conserves energy. Using physics principles, it explains how a shorter lever (foot closer to the body) requires less energy. The script debunks this myth with 3D camera analysis, showing that relaxed running with a natural foot swing is more energy-efficient. It also touches on the importance of cadence and the biomechanics of running, concluding that the height of the foot and knee movement varies with pace and should be relaxed, not forced.

Takeaways

• 🚶‍♂️ Keeping feet close to the ground while running is a common mistake and can actually cost more energy.
• 🔍 The law of physics explains that a longer pendulum requires more energy to move than a shorter one.
• 🎭 In figure skating, bringing arms closer to the body increases spin speed, illustrating the energy efficiency of keeping limbs close to the center of mass.
• 🦿 Lifting the foot higher reduces the lever arm, making it easier and less energy-consuming compared to keeping the foot close to the ground.
• 🔄 The mechanical push of the tibia and the utilization of the stretch shortening cycle contribute to energy efficiency when running.
• 🏃‍♂️ Relaxation is key; the foot should not be actively lifted but should naturally swing up due to relaxation.
• 📏 The speaker's 3D camera measurements show that running with feet closer to the ground uses more energy than allowing the foot to swing up naturally.
• 📊 Despite a slightly higher cadence when feet are lifted, the energy cost of moving body parts is significantly lower.
• 🤔 Many recreational runners keep their feet too close to the ground, either due to muscle tension or a misconception about energy conservation.
• 🏃‍♀️ The height of the foot and knees during running should be adjusted based on pace, with faster runs allowing for bigger movements.
• 👟 The speaker emphasizes that personal preference plays a role in running style, but understanding biomechanics can help runners optimize their technique.

Q & A

Why does lifting feet and knees higher while running save energy?

Lifting feet and knees higher reduces the energy cost because it shortens the lever arm, which requires less force to move, similar to how a shorter pendulum moves faster than a longer one.

What is the role of relaxation in running technique?

Relaxation is key in running technique as it allows the foot to naturally swing up without active lifting, reducing energy expenditure.

How does the mechanical push of the tibia contribute to energy efficiency in running?

The mechanical push of the tibia contributes to better knee drive and a more efficient use of the stretch-shortening cycle, which helps save energy.

What is the 'rubber band effect' mentioned in the script?

The 'rubber band effect' refers to the energy saved from the stretch-shortening cycle, which is a phenomenon where the elastic properties of muscles help in conserving energy during movement.

How does the position of the foot relative to the center of mass affect running efficiency?

The foot moving closer to the center of mass reduces the lever arm, making it easier and less energy-consuming to move.

What does the script suggest about the relationship between cadence and energy cost in running?

The script indicates that even with a slightly higher cadence when the feet are lifted higher, the cost of moving body parts is significantly lower due to the reduced lever arm.

Why do some runners keep their feet too close to the ground?

Some runners keep their feet close to the ground because they believe it saves energy, or they are not good at relaxing, leading to resistance and higher energy cost.

How can the biomechanics of running be improved through relaxation?

By relaxing and allowing movements to happen naturally without forcing them, runners can improve their biomechanics and reduce energy expenditure.

What role does the core play in efficient running according to the script?

The core plays a significant role in efficient running by aiding in the movement of the hips and allowing for a more relaxed and natural running motion.

How does the height of the foot and knees during running relate to running pace?

The faster the pace, the bigger the movement of the foot and knees should be. It's important to adjust the height of the foot and knees according to the speed of running.

What does the script suggest about personal preference in running technique?

The script acknowledges personal preference in running technique, stating that if a runner prefers to keep their feet close to the ground, they should do so, as long as it's done with proper biomechanics.

Outlines

00:00

🏃‍♂️ Efficient Running Technique

The paragraph discusses the energy efficiency of running techniques. It explains that lifting feet and knees higher during running doesn't necessarily cost more energy, contrary to a common misconception. The analogy of a pendulum is used to illustrate how a longer lever (like lifting feet higher) requires more energy to move. The speaker then introduces the concept of 'relaxation' in running, suggesting that it's not about actively lifting but allowing the foot to naturally swing up due to the body's momentum. The speaker supports this with data from 3D camera tests, showing that running with feet closer to the ground actually uses more energy than allowing the feet to naturally lift. The paragraph concludes by addressing the potential impact of cadence on energy expenditure, hinting that a higher cadence might be a factor in the energy cost when feet are lifted higher.

05:02

📊 Debunking Common Running Myths

This paragraph continues the discussion on running technique, focusing on the misconception that keeping feet close to the ground saves energy. The speaker clarifies that this belief is not supported by the physics of motion and energy expenditure. They explain that many recreational runners keep their feet too close to the ground, either due to muscle tension or a misunderstanding of energy efficiency. The speaker emphasizes the importance of relaxation and natural movement over forced lifting of the feet. They also mention that the optimal height of the foot and knee movement varies with running pace. The paragraph ends with a call to action for viewers to like, subscribe, and consider the speaker's online course for more information on running biomechanics.

Keywords

💡Energy Conservation

Energy conservation in the context of the video refers to the concept of using the least amount of energy while running. The video explains that by not lifting feet too high, a runner can conserve energy, similar to how it takes less energy to lift an arm when it's closer to the body. This concept is central to understanding running efficiency and is illustrated by comparing the energy cost of different running techniques.

💡Lever

A lever, in the context of the video, is used to explain the physics of movement, particularly how a long pendulum or lever requires more energy to move than a shorter one. The script uses the analogy of a metronome to demonstrate this, where a longer pendulum (lever) moves slower, requiring more energy, while a shorter one moves faster and requires less.

💡Center of Mass

The center of mass is a point where an object's weight is considered to be concentrated. In running, bringing the foot closer to the center of mass is shown to be more energy-efficient. The video uses figure skating as an example, where spinning with arms out stretches the lever and slows the spin, while pulling arms in reduces the lever's length and increases speed.

💡Mechanical Push

The mechanical push refers to the force generated by the tibia during the running motion, which contributes to a better knee drive. This concept is part of the discussion on how the natural movement of the leg can assist in running efficiency, using the stretch shortening cycle to enhance performance without additional energy expenditure.

💡Stretch Shortening Cycle

The stretch shortening cycle is a phenomenon where the muscles experience a stretch followed by a shortening, which can store and release energy efficiently. The video mentions this cycle as a factor that contributes to energy savings in running, particularly when the leg movement is relaxed and not forced.

💡Relaxation

Relaxation in the video script refers to the technique of not actively lifting the feet and knees but allowing them to move naturally. This approach is contrasted with forced movement, suggesting that a relaxed gait can lead to more efficient energy use in running, as demonstrated by the 3D camera tests mentioned.

💡3D Cameras

3D cameras are used in the video to measure the energy expenditure of different running techniques. They provide a scientific method to compare the energy cost of running with feet close to the ground versus a more relaxed, higher foot movement, thus offering empirical evidence to support the video's claims.

💡Cadence

Cadence in running refers to the number of steps taken per minute. The video discusses how cadence might affect energy expenditure, noting that a higher cadence (faster steps) could potentially use more energy. However, the script reveals that even with a higher cadence when running with relaxed knees, the energy cost of moving body parts was lower.

💡Biomechanics

Biomechanics is the study of the mechanical laws relating to the movement of living organisms. In the video, biomechanics is applied to analyze running techniques and understand how different movements affect energy use. The video aims to educate viewers on the biomechanics of running to improve efficiency.

💡Pace

Pace in running is the speed at which a runner completes a race or runs a certain distance. The video script mentions that the height of the foot and knee movement should correspond to the pace of running, with faster paces allowing for bigger movements. This highlights the importance of adapting technique to the speed of running.

💡Forced Movement

Forced movement is contrasted with natural, relaxed movement in the video. It refers to the unnecessary use of muscle force to lift the feet, which can lead to increased energy expenditure. The video suggests that letting the foot 'dangle up' naturally is more efficient than forcing it upwards.

Highlights

Running technique misconception: Lifting feet and knees higher doesn't necessarily save energy.

Physics analogy: A longer pendulum requires more energy to move than a shorter one.

Figure skating example: Arms out stretch slows down spin, illustrating the energy cost of leverage.

Foot movement closer to the center of mass is more energy-efficient.

Mechanical push of the tibia and knee drive contribute to energy efficiency in running.

The 'rubber band effect' from the stretch shortening cycle aids in energy conservation.

Relaxation is key to letting the foot swing up naturally, rather than actively lifting.

3D camera measurements provide empirical evidence of energy expenditure in running.

Tests show that running with feet close to the ground uses more energy than relaxed running.

Cadence impact: Higher cadence when feet are lifted, but energy cost is lower.

The common mistake of keeping feet too close to the ground leads to inefficient running.

Efficient running involves not forcing the movement but allowing it through relaxation.

The height of the foot and knees during running should match the running pace.

Personal preference in running style should be respected, but biomechanics should be understood.

The video provides a comprehensive look into the biomechanics of running.

Encouragement to like, subscribe, and explore more content on the channel.

Mention of an online course for further learning on running techniques.

Transcripts

by not lifting my feet so much but keep

them close to the ground

I save a lot of energy

yes I get it it makes so much sense it

must obviously cost more energy to lift

your feet and knees more when you run

then do it less

just like it takes more energy for me to

lift my arm like this compared to

not lifting the arm if I don't lift my

arm no energy is used at all

seems much better than wasting muscle

power on a lift right this is a common

mistake when talking about running

technique you compare how it works when

you're standing still with what happens

when you're in motion like when you're

running we can start by looking at how

the law of physics work a long pendulum

oral lever costs more energy to move

than a shorter pendulum or a liver this

works much like an old-fashioned

metronome when the weight is placed at

the top you get a long pendulum that

moves slowly and when you move the

weight down to make the pendulum shorter

it goes faster

this is very clear also in figure

skating if you hold your arms out from

your body when you do a pirate and spin

and turn around it goes slow whereas the

period is quite fast when you bring your

hands and arms closer to your Central

Mass

if the foot comes up a little bit more

the foot moves closer to your center of

mass which makes it easier and costs

less energy than if the foot moves

closer to the ground

[Music]

thank you

and there are actually several other

things that makes a slightly higher foot

contribute to your running costs less

energy such as a mechanical push of the

tibia that will contribute to a better

knee drive and a better utilization of

the rubber band effect you get from the

stretch shortening cycle as well as

several other factors but now you might

think that lifting your feet and knees

still costs more energy than what you

save through the shorter levers the

movements closer to the center of mass

and the mechanical assistance and all

the rest but it's not at all about

actively lifting your feet and knees

instead it's all about relaxation and

letting the foot kind of just dangle up

you relax it and it will swing up it's

all about relaxation do I have any proof

that it works like this yes of course I

do with my 3D cameras I can measure how

much energy it takes to move your body

parts when you run note that I'm now

talking not at all about moving the body

up and down but only the energy it takes

to move the arms and the legs in

relation to your Central Mass adjusted

to tests one where I did not lift my

feet and knees so much but I just let my

feet move quite close to the ground on

the way forward and backwards and one

when I did the relaxation thing note the

relaxation that makes my feet swing up

by themselves and now I put these two

tests to together the darker thinner

lines is as you can see when I ran with

my feet close to the ground while the

thicker lighter lines is when I relaxed

and left my foot swing up looking at

these two figures it's easy to think

that it costs more energy to move the

body parts more that is the thicker

lighter lines where I bring my foot up

then we look at the bars that show how

much energy was used to move my body

parts the light colored bars to the left

is showing when I let my feet come up

and that bar is lower then the darker

bar on the right which is where I had my

feet close to the ground

so the fade close to the ground costs

more energy and this is a measurable

fact but what about my Cadence since it

costs more energy to move things fast

compared to slow maybe I had a higher

Cadence when I had my feet close to the

ground and that's why it costs more

energy I actually didn't think about my

Cadence at all when I did the tests but

it turns out that I had a little higher

Cadence in one of the tests but if we

look at the Cadence we can see that I

had a slightly higher Cadence when the

feet came up higher so I moved my legs

both faster and in a bigger movement

than when I relaxed my knees but the

cost of moving my body parts was

significantly lower it may sound so

logical and like common sense to save

energy by keeping your feet close to the

ground but when you measure the cost of

energy and know a bit about the law of

physics it's quite easy to see that this

is not the case the recent many

recreational Runners have their feet too

close to the ground is usually because

they use their thigh muscles to prevent

the movement some Runners because they

think that having their feet close to

the ground costs less energy and some

are just bad at relaxing and then they

put energy into resisting the movement

which leads to costing more energy to

move the foot and the leg forward again

they spend energy to get a movement that

costs even more energy it's like paying

a monthly fee to a club to get a higher

rent as opposed to not paying a monthly

fee and get lower rent at least as long

as you get the movement through

relaxation and partly on how you move

your hip and your core and you don't

actually lift your feet with muscle

Force there is a big difference between

to do a movement to force it and to

letting the movement happen just like

you learn in my online course and of

course I would like to add that exactly

how high the foot and the knees should

be depends very much on how fast you run

the faster the pace the bigger the

movement and as always you do what you

want if you like to have your feet close

to the ground when you run I think you

should have your feet close to the

ground when you run I don't care I'm

just here to tell you how the

biomechanics of running works

I truly hope you liked that video and if

you did please click the like button and

maybe also the Subscribe button and feel

free to check out all the other content

I have here on my channel and maybe you

are also interested in my online course

you'll find it at fredexilen.com