- Welcome back to the Triathlon Training Explained show,

powered by TrainingPeaks, now if from time

to time you are riding indoors, perhaps

on a Turbo Trainer as I am today,

then you will have quite likely

at some point complained that it feels somewhat hard,

or maybe considerably harder than when you ride outdoors.

Your heart rate's higher, your power's lower,

your FTP maybe feels a bit out

of reach, what is going on, well you'll be pleased

to know that you are definitely not alone.

Today, I'm gonna be exploring that conundrum and be looking

at how it happens and what you can do about it.

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Now, I must admit there have been times that I've jumped

on the indoor trainer and I've wondered,

what the heck is going in with my legs?

And it can really play with your head

because effort just seems so much harder to achieve.

Sometimes, impossible whereas normally you're knocking 'em

out of the park when you're outside on the road.

So, what do we think is happening?

Well, I've been out and I've asked you just that.

Now, why is it harder, indoor training?

- Because you don't get any rest.

You have to keep going all the time.

You're not able to glide and you

have to keep it in the zone or rate area

which is much more difficult when you're on the bike.

- The thing I find hard about indoor training

is that there's no distractions,

there's no changing gears, there's no steering,

there's no needing to be aware of traffic.

So, you really have to focus on

the pain, and how much it hurts.

- I think it's because of the heat

and you don't have the wind coming against

you cooling you down, so you can easily

overheat which can make you feel

like you are putting in much more

effort than you actually are.

- It's a definite love/hate relationship

with the indoor trainer, and it

makes training a lot harder.

There's no free wheeling, coasting,

sitting behind people, there's constant

tension on the chain as you're pushing

through the session.

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- Well, there are some very good theories there,

but let's see what the science says.

Now, one theory is that it's due

to a reduced cooling effect.

See, the human body has quite

a small and finite range it can

efficiently operate in, and that's

between 36.5 and 37.5 degrees Celsius,

and this is what's considered

our normal body temperature.

Now, if we go just a fraction above that

we can start to feel a little bit off

and actually, our training like

cycling might start to feel a

bit more laboured.

If we just go about three degrees

Celsius above maybe to around

40 degrees Celsius

we can really start to feel quite bad,

and actually we can start to

experience the onset of hyperthermia.

Now, obviously when we're cycling indoors

we are stationary, but our bodies

are still creating vast amounts

of this energy to power our legs

and keep things working.

So, this is where things get really interesting

because the cells that are in our body

actually get their energy from food

and then creating and using that

through ATP molecules, and they

are then used to make our body work

and make our legs work, and we have to cycle.

Through this whole conversion,

it's actually only an overall efficiency

of around 25% that's actually used

to make our legs work.

The other 75% is, wait for it,

is lost through heat.

So, if you take a cyclist cruising along

outside at about 30 k.p.h.

Their experience, a nice wind, a nice breeze,

a bit of headwind.

That's equivalent of a big big ol' fan

around 30 k.p.h or perhaps even more

depending on the conditions.

When we're riding inside, that headwind

that breeze, it's all gone.

So, you can start to understand

how the body starts to feel

the effects of this heat, and it

starts to respond in a few ways.

Firstly, we have a slight increase in our heart rate.

Secondly, the blood starts to

shunt, and move away from our muscles

in an attempt to dissipate the heat.

So, it goes towards our skin to try to relieve

that heat out of our body,

but through doing so it's obviously

taking oxygen away from our muscles

which then might start to experience

a slight loss in power.

Another way it tries to dissipate the heat

is through sweat, and in doing so

we can end up feeling slightly more dehydrated

and again, a loss in performance.

Also, as temperatures really rise

then our head and our brain literally

cook, meaning it leads to a decrease

in motivation, concentration,

and perhaps even lowering our pain threshold.

But, of course we all know that,

that's why we use a fan.

A fan is there to essentially

recreate the wind to try to keep

us cool, to wick the sweat away

from our skin, and stop us from overheating.

What I would say, is that I know

from experience that I am pretty

much always dripping with sweat

when I get off an indoor training session,

despite having a fan.

So, perhaps it does contribute

in some way to making indoor training harder.

Now, another theory is that it's

due to being in a fixed position.

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So, without the ability to actually

move the bike, we're causing ourselves

to use more isolated muscles,

that perhaps aren't used to working quite so hard.

When we ride outside on the road,

we're able to shift our body weight around,

get a powerful bike, move the bike around.

In turn, we can start using more muscle groups,

even our upper body, our core,

as well as obviously our legs

to really help produce as much power

as possible, and actually, through

doing that we can allow some muscles

to recover and rest, whilst others

are working to overall help to

produce as much power as possible.

Another thing athletes do complain about

is that some muscles, or certain areas

of muscles might hurt.

Such as, adductors coming up the inside of the leg.

That's a real classic one because

when we're riding outdoors we

don't tend to utilise and use

those muscles quite so much.

They seem to get quite a hammering

when we're riding indoors and that

can really contribute to a slight loss in power.

What I would say is that, with

time when you're riding indoors,

you will start to train those

muscles up, condition them,

get better at using them,

and hopefully start to find

it's less slightly of an effort.

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The indoor trainer also has the

ability to suck the life out of

even the most motivated of athletes.

So, if you're riding indoors,

maybe in your garage, your dark garage

next to your lawn mower, and a bunch of tools;

Let's be honest, that is nowhere

near as motivating as riding outside

on the road, on a clear sunny day.

So, if you're not as motivated

that is going to contribute

to a loss in power.

So, what I would say is for indoor training

try to tailor your sessions specifically

for indoor training, keep them engaging

keep them interesting, keep that body guessing.

Try to make them slightly shorter, more intense.

Maybe don't do quite so many of

the longer rides indoors, otherwise

you are just going to mentally burn yourself out.

On that note, also things like Zwift, and other

virtual indoor training platforms are great

for keeping you interested, and engaged

in indoor training.

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But, the big reason I believe

comes from the indoor trainer itself,

or at least from some indoor trainers.

See, when you're cycling outside on the road

and you stop peddling, you coast,

you just keep on going,

But when you're inside on an indoor

trainer, and you stop cycling,

you pretty much come to a

stop within seconds, or at least,

on some indoor trainers.

So, what's happening is when you're outside

you have the momentum from your

own body weight, your bike weight,

and that just keeps you going

so you can free wheel, and you

can come off the gas and coast.

Whereas, inside on an indoor trainer,

you have a flywheel that's attached

to the resistance unit, and what

that flywheel tries to do is,

it tries to replicate that feeling

of riding outside on the road.

But, from experience, and we all know this,

It doesn't really do it that well.

So, what you're having to do is

work harder to try and maintain that momentum.

Because of this flywheel, it also

changes the way that we apply force

throughout the peddle strikes.

So, when we're cycling outside on the road

you may think that you're applying force

evenly and smoothly throughout

the whole peddle strike, but in actual fact

what you're probably doing is

applying force through the down stroke,

and that is also aiding the recovery

of the other leg back up to the top

of the stroke, and vice versa.

This all changes slightly when we start

to go up a hill, because we need

to apply force throughout the whole

peddle strike to maintain that momentum,

otherwise we'll either fall off our bike

or fall back down the hill, and that

is very similar to when we are riding

on an indoor trainer due to that

flywheel, and that inertia that we've

got to overcome on the flywheel,

and try to maintain that momentum.

Now, all of these factors are contributing

to what is making it harder,

and considerably harder than when we'd

ride out on the road where we've got

minimal resistance from tyres

and from wind for instance.

But, fortunately these issues are

becoming less and less, due to

advances in the flywheels.

We've got bigger flywheels on the dumb trainers

but most importantly, it's due to

these smart trainers, and direct drive trainers

as I'm using today.

So, by taking the rear wheel out

of the equation, and now including

this larger heavier flywheel,