How to Save Your Muscles From Aging

Summary

This video script challenges the misconception that heavy weightlifting is solely for bodybuilders and athletes, emphasizing its importance for everyone to prevent muscle mass loss with age. It explains muscle fiber types, the nervous system's role in motor unit recruitment, and how heavy resistance training and explosive exercises can stimulate fast twitch fibers, crucial for maintaining strength and foot speed as we age.

Takeaways

• 🏋️ Heavy resistance training is beneficial for everyone, not just bodybuilders or athletes, as it helps in preserving muscle mass.
• 🔢 Starting in our 30s, we can lose 3-5% of muscle mass per decade, which increases to up to 10% per decade after 50.
• 💪 Heavy resistance training is more effective at preserving muscle mass compared to other forms of exercise.
• 🧬 Muscles are made up of muscle fibers, which are classified into fast twitch and slow twitch fibers, with the former being more susceptible to loss with aging.
• ⚡ Fast twitch fibers contract with more force and velocity but fatigue quickly, while slow twitch fibers are more resistant to fatigue and ideal for endurance activities.
• 🧠 The nervous system recruits muscle fibers in a specific sequence, starting with slow twitch fibers and then fast twitch as the load increases.
• 🏃‍♂️ Explosive exercises, like sprinting or jumping, can also engage and stimulate fast twitch muscle fibers due to their requirement for speed.
• 📈 To maintain and improve fast twitch fibers, 10-15 working sets per muscle group per week are recommended, with a heavy load that allows only 4-8 repetitions.
• 🚴‍♀️ Endurance athletes and those with active lifestyles may still benefit from incorporating heavy resistance training to stimulate underused fast twitch fibers.
• 🤔 Concerns about muscle size from heavy training are unfounded, as strength gains can be achieved without significant hypertrophy.
• 👴 Preserving fast twitch fibers can help maintain foot speed and agility, potentially reducing the risk of falls and injuries in older age.

Q & A

Why should individuals include heavy resistance training in their exercise routine?

Heavy resistance training is essential because it helps preserve muscle mass, which is crucial as we age. Starting in our 30s, we can lose up to 5% of muscle mass per decade, and this loss accelerates in our 50s. Heavy resistance training is particularly effective at preserving muscle mass compared to other forms of exercise.

What is the difference between fast twitch and slow twitch muscle fibers, and why are they important for muscle mass preservation?

Fast twitch muscle fibers contract with more velocity and force and have a greater diameter, but they fatigue quickly. Slow twitch fibers contract with less velocity and force but are fatigue resistant and ideal for endurance activities. As we age, we lose a greater proportion of fast twitch fibers compared to slow twitch fibers, which is why heavy resistance training is important to stimulate and preserve these fibers.

How does the nervous system's recruitment of muscle fibers influence muscle mass loss with aging?

The nervous system recruits muscle fibers in a specific sequence. It first activates slow twitch fibers and then fast twitch fibers as the load increases. This recruitment pattern means that fast twitch fibers, which are more prone to loss with aging, are less frequently engaged in everyday activities and lighter forms of exercise, contributing to their decline.

What is the All or Nothing principle in muscle contraction, and how does it relate to motor units?

The All or Nothing principle states that when a motor neuron fires, all the muscle fibers it controls contract at full force. This principle is important because it allows for force modulation during activities. Each muscle is divided into multiple motor units, each controlled by a different motor neuron, which helps in modulating force based on the activity.

How can heavy resistance training be incorporated into an existing exercise routine?

Heavy resistance training can be added to a routine by including exercises that involve heavy loads, such as weightlifting, where the weight is heavy enough to allow only four to eight repetitions. This can be spread throughout the week or lumped into one day, depending on the individual's preference and schedule.

What is the recommended number of working sets per muscle group per week to maintain and improve fast twitch fibers?

The recommended number of working sets per muscle group per week to maintain and improve fast twitch fibers is about 10 to 15 sets. These sets should involve heavy loads that allow for only four to eight repetitions.

Can heavy resistance training cause muscles to become too big, and if so, how can this be avoided?

Heavy resistance training does not necessarily cause muscles to become too big. While it increases strength, it does not significantly contribute to muscle hypertrophy or size increase unless the training volume is significantly increased with more repetitions and sets. For those concerned about muscle size, focusing on strength training with moderate volume can help avoid excessive muscle growth.

How can explosive exercises be incorporated into a workout routine to engage fast twitch fibers?

Explosive exercises can be incorporated into a workout routine by including activities that require fast and powerful movements, such as sprinting, vertical jumps, or medicine ball throws. These exercises engage fast twitch fibers by requiring quick and forceful contractions.

What is the significance of foot speed in relation to muscle fiber preservation and aging?

Foot speed, which is largely influenced by fast twitch fibers, is significant for maintaining agility and balance as we age. Preserving these fibers through heavy resistance training can help maintain foot speed, potentially reducing the risk of falls and injuries, such as hip fractures, which are common and detrimental in older adults.

How does the Nutrisense Continuous Glucose Monitor (CGM) relate to the discussion on heavy resistance training?

The Nutrisense CGM is a device that monitors blood glucose levels, which can be impacted by various factors, including exercise. In the context of heavy resistance training, it can provide insights into how such training affects blood glucose levels, which could be useful for optimizing athletic performance and recovery.

Outlines

00:00

🏋️‍♂️ The Importance of Heavy Resistance Training

This paragraph introduces the concept that heavy weightlifting is not just for a select few athletes but should be incorporated into everyone's routine. It challenges the notion that lighter weight training, long-distance running, or yoga are sufficient. The speaker, Jonathan, emphasizes the importance of preserving muscle mass against the natural aging process, which leads to significant muscle loss. The paragraph sets the stage for a discussion on why heavy resistance training is superior for maintaining muscle mass, particularly focusing on the role of muscle fibers and how they respond to different types of exercise.

05:02

💪 Understanding Muscle Fibers and Aging

The second paragraph delves into the physiological aspects of muscle fibers, distinguishing between fast twitch and slow twitch fibers. It explains that fast twitch fibers are more forceful but tire quickly, while slow twitch fibers are more resistant to fatigue. The paragraph highlights that muscle mass loss with aging disproportionately affects fast twitch fibers, which is a critical factor in the decline of physical performance. The speaker uses the biceps brachii muscle as an example to illustrate how muscle fibers work and the importance of heavy resistance training in preserving them. Additionally, the paragraph introduces the concept of motor unit recruitment and hints at the role of the nervous system in this process.

10:03

🧠 Motor Unit Recruitment and the Role of the Nervous System

This paragraph explores the nervous system's role in motor unit recruitment, which is essential for understanding muscle fiber engagement during exercise. The speaker uses a creative pencil analogy to demonstrate how motor units are activated in sequence based on the load, with slow twitch motor units being recruited first, followed by fast twitch units as the weight increases. The paragraph explains the All or Nothing principle of muscle contraction and emphasizes the need for heavy resistance to stimulate fast twitch fibers. It also touches on explosive exercises as an alternative way to engage these fibers, providing a foundation for the subsequent discussion on exercise choices.

15:04

🏃‍♂️ Preserving Fast Twitch Fibers Through Strength and Explosive Training

The fourth paragraph discusses the importance of engaging fast twitch fibers to prevent muscle mass loss associated with aging. It suggests that incorporating strength training with heavy loads and explosive exercises into one's routine can effectively stimulate these fibers. The speaker clarifies that this type of training does not necessarily lead to significant muscle hypertrophy, alleviating concerns about 'getting too big.' The paragraph also introduces the concept of foot speed, linking the preservation of fast twitch fibers to the prevention of falls in older age, thereby highlighting the practical benefits of heavy resistance and explosive training beyond aesthetic or athletic gains.

Keywords

💡Heavy Resistance Training

Heavy resistance training refers to exercises that involve lifting weights heavy enough to challenge the muscles, typically resulting in muscle fatigue after a few repetitions. In the video, it is emphasized as an essential component of any fitness routine to prevent muscle mass loss, especially as we age. The script mentions that this type of training is more effective at preserving muscle mass compared to other forms of exercise.

💡Muscle Fibers

Muscle fibers are the individual cells that make up skeletal muscles, capable of contracting to produce movement. The script distinguishes between fast twitch and slow twitch muscle fibers, highlighting that fast twitch fibers are more susceptible to atrophy with age and that heavy resistance training is crucial for their maintenance.

💡Fast Twitch Fibers

Fast twitch fibers are a type of muscle fiber that contracts quickly and forcefully but fatigues rapidly. The video explains that these fibers are more likely to be lost as we age, contributing to a decrease in muscle mass and strength. The script uses the example of lifting heavy weights to illustrate how these fibers can be engaged and preserved.

💡Slow Twitch Fibers

Slow twitch fibers are muscle fibers that contract more slowly, with less force, but are resistant to fatigue, making them ideal for endurance activities. The script notes that while these fibers are less prone to loss with age, a balanced approach to exercise is still necessary to maintain overall muscle health.

💡Motor Units

A motor unit consists of a motor neuron and the muscle fibers it innervates. The video script uses the concept of motor units to explain how the nervous system recruits muscle fibers during exercise, with heavy resistance training being particularly effective at engaging fast twitch motor units.

💡All or Nothing Principle

The All or Nothing Principle states that when a motor neuron fires, all the muscle fibers it controls contract at full force. The script explains this principle in the context of motor unit recruitment, emphasizing the importance of having multiple motor units to modulate force during activities.

💡Nutrisense

Nutrisense is a sponsor mentioned in the script that offers a continuous glucose monitoring (CGM) program. The script discusses how the CGM device and app can help monitor blood glucose levels and how factors like exercise can impact these levels, providing insights into athletic performance and recovery.

💡Muscle Mass Loss

Muscle mass loss refers to the natural decline in muscle tissue that occurs with age, especially noticeable from the 30s onwards. The video script discusses the statistics of muscle mass loss and how heavy resistance training can help combat this process.

💡Hypertrophy

Hypertrophy is the increase in muscle size due to the growth of muscle fibers. The script addresses concerns about heavy resistance training leading to unwanted muscle size increases, clarifying that the focus should be on strength rather than hypertrophy for most individuals.

💡Explosive Exercises

Explosive exercises are high-intensity activities that involve quick, powerful movements, such as sprinting or jumping. The video script suggests incorporating these exercises into a training routine to engage fast twitch fibers and add variety to workouts.

💡Foot Speed

Foot speed refers to the quickness and agility of the feet, important for both athletic performance and balance in daily life. The script connects the preservation of fast twitch fibers with maintaining foot speed, potentially reducing the risk of falls in older age.

Highlights

Heavy resistance training is beneficial for everyone, not just bodybuilders or athletes.

Long-distance running and lighter weight training may not be sufficient to maintain muscle mass.

Muscle mass declines significantly from the 30s onwards, with a more rapid decrease after 50.

Heavy resistance training is more effective at preserving muscle mass than other forms of exercise.

Muscles are composed of muscle fibers, including fast twitch and slow twitch types.

Fast twitch fibers are more forceful but fatigue quickly, while slow twitch fibers are endurance-oriented.

Aging leads to a disproportionate loss of fast twitch fibers compared to slow twitch fibers.

The nervous system's recruitment sequence explains why fast twitch fibers are more affected by aging.

Nutrisense CGM helps monitor blood glucose levels and understand their impact on health.

Motor units and the All or Nothing principle are key to understanding muscle fiber recruitment.

Heavy loads and explosive movements are necessary to engage fast twitch muscle fibers.

Incorporating strength training can help maintain fast twitch fibers and prevent muscle mass loss.

Only 10 to 15 working sets per muscle group per week are needed to maintain fast twitch fibers.

Heavy resistance training does not necessarily lead to significant muscle hypertrophy.

Preserving fast twitch fibers can improve foot speed and potentially reduce the risk of falls in older age.

Explosive exercises can be creatively incorporated into routines for variety and fun.

Endurance athletes can benefit from dedicated strength training days to engage all muscle fiber types.

Transcripts

Have you ever thought that heavy  weightlifting is only for bodybuilders,  

power lifters or certain types of  athletes? Well, in today's video,  

we're going to find that this is definitely not  the case and no matter who you are you should  

likely be including some form or variation of  heavy resistance training into your routine.

Now, you still might be pushing back  and saying "wait a minute Jonathan,  

I do things like consistent long distance running,  

throw in some weight training throughout the week  but it's of a lighter weight or lighter load,  

maybe even throwing in some yoga in  there". Well, still probably not enough.

We'll talk about why this is by taking a look  at the muscles, discussing aging and of course,  

talk about how we could add this type of training  to a current routine or even a new routine.  

It's going to be an important one, so, let's  jump right into this anatomical awesomeness.

[Intro]

So, first let's start with the "why". Why do these  skeletal muscles require heavy resistance training  

and therefore why should all of us participate  in this? Well, maybe you've heard some alarming  

statistics that starting in our 30s, we can lose  anywhere from three to five percent of our muscle  

mass per decade but when we get to our 50s, we can  lose as much as 10% of our muscle mass per decade.  

That's quite alarming and kind of scary to think  about but you might also be thinking "well wait,  

can't we combat that or at least slow that  process down through exercise?" and the answer  

is yes and that's one of the main points of  this video but many of the other forms of  

exercise just aren't as effective at preserving  muscle mass like heavy resistance training is.

So why is heavy resistance training better at  preserving muscle mass than the other types of  

exercise? Well, the answer to that lies in how  muscles actually work. So, let's use the biceps  

brachii muscle as our example here but keep  in mind we can apply this information to any  

of the other skeletal muscles that we would  be working out or exercising but if we were  

to take a look at this whole biceps muscle, the  whole muscle is going to be made up of thousands  

of string like cells called Muscle Fibers and  you could just even call them muscle cells.

So, if I use those terms interchangeably  we're talking about the same thing but these  

muscle fibers have an amazing ability  to contract and when they contract,  

this would cause a pulling on the  bone via the tendon and that would  

move your skeleton in certain directions  depending on what muscle you're contracting.

Now, another thing that's important  that we talk about with these muscle  

fibers is that if we analyze the  muscle fibers within this muscle,  

we would see that some of them are classified  as fast twitch muscle fibers and others are  

classified as slow twitch muscle fibers and this  is definitely important to our muscle mass story.

So, why do the different fiber types matter  when it comes to a reduction in muscle mass  

as we age? Well, let's go over some of the  characteristics of these fiber types and then  

we'll bring that together. The fast twitch muscle  fibers, as the name implies, contract with more  

velocity and more force and tend to have a greater  diameter when compared to the slow twitch fibers.

Now, one of the dry backs of the fast twitch  fibers is that they fatigue rather quickly  

and we do have to acknowledge to all the  anatomy and physiology Geeks out there  

that we could further classify or subdivide the  fast twitch fibers but that's for another time.

The slow twitch fibers contract with less  velocity, less force and have a smaller  

diameter but they are fatigue resistant; they're  great for endurance type activities. So again,  

how does this relate to reduction of muscle mass  as we age? When we have this reduction of muscle  

mass, it's not like the mass reduction is uniform  between the fiber types and what I mean by that is  

it's not like 50% of that reduction in muscle mass  comes from the slow twitch if the other 50 comes  

from the fast twitch. It is actually much more  biased to the fast twitch fibers meaning we lose a  

much greater proportion of the fast twitch fibers  as we age as compared to the slow twitch fibers.

So, this probably raises another question for  you; why do we lose such a greater proportion  

of the fast twitch fibers versus the slow twitch  fibers with aging? Well, a big part of this answer  

has to do with the sequence in which the nervous  system recruits the slow twitch fibers versus how  

it recruits the fast twitch fibers and this  will also help us to understand why certain  

activities do a better job at recruiting  or engaging those fast twitch fibers.

So, let's get into this by talking about  the nervous system, motor recruitment  

and pencils[00:04:09] but real quick I  want to talk about this cool device on  

the back of my arm by saying thank you to  the sponsor of today's video Nutrisense.

Nutrisense is a continuous glucose monitoring  program that monitors your blood sugar levels  

which are more appropriately referred to  as your blood glucose levels. It does it  

through this nifty little device called a  Continuous Glucose Monitor or CGM that goes  

on the back of your arm or for you anatomy  nerds out there, on the posterior brachium.

The CGM then easily syncs with the  nutrisense app which allows you to  

monitor your blood glucose levels throughout  the day and see how things like food, sleep,  

exercise and even how stress impacts your blood  glucose levels. For me, it was very interesting  

and a lot of fun to do little foods experiments  to see which types of foods might spike my blood  

glucose levels. Probably not a big shocker what  that ice cream was going to do but it was also  

awesome to see how exercise, like stimulating  those fast twitch muscle fibers could affect  

those blood glucose levels which could help  provide valuable Insight on things like how I  

might time certain food types to optimize  athletic performance and even recovery.

The Nutrisense CGM program also comes  with helpful advice from a dietitian,  

which means I can help you understand your glucose  numbers, provide some accountability and also help  

you find that ideal personalized diet. That first  month of the dietitian is actually free and then  

just fifty dollars a month after that. So, if  you're interested in trying this amazing program  

and getting one of these nifty little CGMs, check  out the link on the screen and use the discount  

code "HUMAN25". We'll also include that link as  well as the information in the description below.

So, how does the nervous system and motor unit  recruitment help us to better understand why we  

lose a greater proportion of fast twitch fibers?  And what in the world did I mean by pencils? Well,  

here are the pencils and this is  representing a full muscle like  

the biceps. You can totally tell that it  resembles the real biceps but really we're  

just using this to help us understand  motor unit and motor unit recruitment.

So, pretend this is a whole biceps  like a cross section through it. Each  

of the pencils is representing an  individual muscle fiber. The ones  

that I colored with black sharpie are  representing the fast twitch fibers,  

the ones that I didn't color in black sharpie  are representing the slow twitch fibers.

Now, I do want to just mention that we could  go through individual muscles throughout the  

body and we would see that each muscle has  a different proportion of fast twitch versus  

slow twitch and even between individuals we  could see a difference in those proportions.

Now, we could make the argument that a  muscle that has a higher proportion of  

fast twitch fibers might be at greater  risk of reduction but let's not focus  

too much on that and just focus on the  principle of how these different fiber  

types are recruited and that'll also help  us with activity choice with exercise.

So, to do this we need to define what a motor  unit is. A motor unit is the motor neuron and  

the muscle fibers that it controls.  Now, two important things with this:  

one that we understand that each muscle is  subdivided into multiple motor units. So,  

for example this little grouping of fast  twitch fibers would be its own motor unit  

and then we could come over here and say this  grouping of slow twitch fibers would be its  

own motor unit and each one of those motor units  would be controlled by a different motor neuron.

The other reason why this is so important is  because there's this thing called The All or  

Nothing principle and what the All or Nothing  principle says is that when that motor neuron  

fires or sends the signal, every muscle fiber that  it controls will contract at full force and so,  

think about how important that is now  to have individual motor units or the  

whole muscle broken down into multiple motor  units because think of the opposite - what  

if we had one motor neuron controlling  every single muscle fiber per muscle? So  

like one giant motor unit per muscle. You  could see that that would be a big problem  

for the signal being sent into that muscle  because every time that motor neuron fired,  

every single muscle fiber of the muscle will  contract and we'd be contracting at full force  

with every single muscle and that would  be a problem with force modulation, right?

But because we have these muscles  broken down into individual motor units,  

it really helps us to modulate force based upon  the activity we're engaging in or if you know,  

I'm lifting a probe versus a very heavy  weight. So, let's actually use this example  

of me lifting the probe or curling the probe as  compared to say like curling a heavier weight.

Now, I do want to mention or at least clarify  because I kind of alluded to this earlier that  

the motor units are going to be subdivided into  fast twitch motor units that you can see and  

even slow twitch motor units. So maybe a slow  twitch motor unit here, slow twitch motor unit  

over there but we're not going to have this mixing  and matching within the motor units - fast twitch  

motor units slow twitch motor units. And what  we find is that when we start to lift a weight  

or engage the muscles, the first motor units  that we recruit are the slow twitch motor unit.

So, let's say I've got a 10 pound weight and I  start to curl it, I'm likely only going to need  

my slow twitch motor units to move that weight.  Let's say I increase it to 15 or 20 pounds,  

I'll recruit some more of those slow twitch  motor units and I'm going to continue to do  

this until I've exhausted all of my slow  twitch motor units, meaning I've recruited  

all of them and if I continue to increase  the weight, then I'll start tapping in and  

recruiting the fast twitch motor units in  sequence as I continue to increase the load.

So, this gives us the idea of why we need  some level of heavy resistance to actually  

even stimulate and engage those fast twitch  motor units or fast twitch muscle fibers and  

one of the other things that we can do because we  can get creative beyond just doing heavy lifting,  

we could also engage these fast twitch muscle  fibers and recruit these fast switch motor units  

by doing things that are fast and explosive.  Think like a vertical jump or a full-fledged  

sprint and one quick thing I want to address about  our little pencil muscle model here is that you  

actually don't have a motor unit that is this  small, meaning a motor neuron only controlling  

like five or six muscle fibers, that's just,  again for a learning device here, the motor units,  

FYI and the biceps are more like one motor  neuron controlling over a thousand muscle fibers.

So, now we have a pretty good idea as to why these  fast switch fibers are mostly contributing to this  

overall loss of muscle mass as we age and in many  cases, they're contributing to pretty much all of  

it when we're comparing that to the slow twitch  fibers. Now, you probably have come up with some  

ideas about activities or exercises that we could  choose from to help stimulate or at least preserve  

some of these fast twitch fibers and we're  definitely going to talk about those exercises in  

just a second but I do want to approach this from  like a lifestyle approach or a lifestyle example.

Let's say we had a person in their 50s or 60s and  they're actually relatively active; they're doing  

chores around the house, maybe they're working  out in the yard doing gardening yard work,  

you can see that a lot of those activities would  recruit and stimulate those slow twitch fibers but  

the majority of household activities or activities  of daily living don't really require recruitment  

of those fast twitch fibers and so, if this person  isn't also incorporating like a strength training  

routine into their week, you could see how  those fast twitch fibers could go for extended  

periods of time without being stimulated thereby  contributing to that loss over time and as we age.

And let's take this a little bit further -  let's say we have someone who's doing more  

than just the activities of daily living,  they also have an exercise routine and  

some of their exercise choices could be like  steady state cardio at a moderate intensity.  

They're working but they could still hold  a conversation while they're running or  

cycling or maybe they picked yoga or  maybe someone also picked something  

like a form of resistance training but  lighter loads with higher repetitions.

Now, let me be clear, there is nothing wrong with  these exercise choices. There's obvious benefits  

to them, things like cardiovascular improvements,  improvement in mobility and flexibility and even  

improvements in muscular endurance. So, if  you like doing these types of exercises,  

continue to do them. It's just that we could  sprinkle on some addition exercise choices  

to give us some amazing benefits to helping  preserve and maintain these fast twitch fibers  

and another cool thing is that it actually  takes much less than most people think.

The amount of work required to maintain and  even make improvements in the strength of  

these fast twitch fibers is about 10 to 15  working sets per muscle group per week. Now,  

that's not a lot in my opinion and some  of the data is even showing that this  

could be as little as 10 working  sets per muscle group per week.

Now, the amount of load or weight that  we would need for this type of training  

is a weight that's heavy enough that you could  only lift like four to eight repetitions. Now,  

once we start getting to that seven to  eight range and crossing beyond that,  

we're getting to this strength versus hypertrophy  cross over here and so, a lot of people who really  

want to focus on strength will even increase  that weight to where they could only do it  

maybe like two to six repetitions. The point is  it has to be a relatively heavy load for you.

Now, what's interesting about this is that  we could spread these working sets throughout  

the week in a creative way or some people will  actually lump them into one day. For example,  

the endurance athletes will often do a dedicated  strength training day for their legs because  

they've got so many other things going on with  their legs with endurance training because they're  

on their feet running or cycling but again,  you can get pretty creative with all this.

Now, I do want to acknowledge another thing  with the endurance community that yes there are  

naturally days where you increase the intensity  because you increase the speed of the run and you  

can start pulling in some of those fast twitch  fibers as the speed increases in the run or if  

you're on a bike but there's still going to be a  percentage of those fibers that we're likely not  

tapping into, so again the benefit of this  High Resistance strength training is going  

to be there or we could also get a little  bit creative with some explosive exercises.

Including explosive exercises into this type of  training is where it really gets fun in my opinion  

because it even opens up the doors wider for more  variety and more fun while you're exercising and  

working out. So, remember when we mentioned how we  recruit the muscle fibers one of the main ways was  

to increase the load and the more load we add the  more we have to recruit those fast twitch fibers.

The other way was to do something as fast or  as explosive as possible like a full-fledged  

sprint or a vertical jump. So, you could  get creative with these 10 to 15 working  

sets where maybe on one day you did a  squad[00:14:08] or a squat variation of  

heavy weightlifting of five to eight sets  and then another day you decided to do box  

jumps which would work those same muscle  groups in this explosive manner but kind  

of change the variety and have some  fun with different exercise choices.

For the upper body you could do bench press  one day and then on another day you could do  

explosive medicine ball throws against a  wall right in front of you. And so again,  

a lot of fun, things that you  can kind of mix and match to  

kind of test your abilities and have  some fun with this type of training.

So, let's wrap this up with two thoughts.  Well, one of them is more of a concern  

because some people are concerned that this type  of training might get their muscles too big. Now,  

some of you are out there probably thinking  "Well, why wouldn't you want your muscles to  

get big?" well, there are plenty  of people who are not under that  

umbrella and think "Okay, I don't want big  muscles. Can I get these strength benefits  

without getting huge?" if you will and  the answer is yes. This form of training,  

this type of strength training or true strength  training doesn't cause a huge adaptation as far  

as hypertrophy or an increase in muscle size.  You can get great increases in strength without  

increasing the size of the muscle very  much, again with this type of training.

People who are trying to build muscle as far  as size, they call this hypertrophy again,  

they're going to need a lot more volume  than 10 working sets throughout the week;  

increased repetitions and increased sets Etc. So,  

for those of you who are concerned about  that, don't worry too much about that.

The other thing I want to mention and talk  about is foot speed. And what do I mean by  

foot speed? Foot speed is definitely important  from an athletic perspective but I want to focus  

on it from the perspective of aging and let  me bring it up like this - maybe some of you  

have had a parent or grandparent or another  loved one who's tripped and fallen later in  

their life and a lot of the times this can be  very detrimental especially if they break a  

bone. You often hear about how bad it is  when someone breaks a hip later in life.

Remember we're talking about all these fast  twitch fibers that are contributing to this  

loss of muscle mass as we age and these are  the fibers that can contract with the most  

velocity contributing to our speed. When  we trip when we're in our 20s or even 30s,  

a lot of the times we have the foot speed to catch  

ourselves with our feet without actually  falling onto our hands or anything else.

So, what if we were able to help preserve  these fibers and therefore the speed later  

in into life and help reduce the risk  of falls and tripping and you could do  

this again by recruiting these fast-fitch  fibers with heavy lifting you could even  

have somebody do things like doing Hopscotch  type activities in the gym or you're having  

them bounce their feet or move their feet  from box to box as quickly as possible  

helping to preserve that foot speed and again,  potentially helping to reduce the risk of falls.

And thanks for watching everyone.  Hopefully I learned something new and  

useful from watching this video. If you're  interested in checking out Nutrisense,  

that link is in the description below and let's  engage those fast twitch muscle fibers of our  

forearm and hand muscles so that you can quickly  click the like and subscribe button as well as  

type like the flash in the comment section. Yes,  that was nerdy. We'll see you in the next video.