[Reporter] That is not rain delicately, beautifully dripping into a puddle.
That is the sweat of ambition
from the brutal heat training technique of Canada's rowing team.
The women's eight working out in the so-called erg dome.
Heat forced in, humidity soaring.
And yes it is as miserable as you're probably imagining.
It did not look fun.
Yeah, it's painful.
It's tough, it's quite gross to think about your body sweating out three to four litres of water
but it's real.
But we kind of get into a grind, get into that flow state
and it makes it a lot easier looking around the room and seeing all your teammates
working just as hard as you and knowing we have a common goal is pretty powerful.
Japan is so notoriously hot that the summer olympics of 1964 were moved to October.
This summer's games could very well be the hottest olympics ever recorded.
So preparing means understanding each athlete reacts differently to the heat
and there are ways to get used to it, mitigate it.
First though you have to measure it.
You swallow this pill.
I took mine this morning at around six in the morning.
[Reporter] In fact they've all had that pill, that isn't really a pill.
It's a thermometer.
The woman who distributes it takes all the measurements, crafts all the plans
and crucially cranks up the heat is physiologist Wendy Peffect.
She has to determine the line between training hard and treading into dangerous territory.
Humidity is expected to be anywhere between 70 and 90 percent
so what that does is it shuts down our most effective heat loss avenue
which is evaporation of sweat
So if your organs get too hot what happens to you?
You shut down
and so the body is always going to preferentially pick safety
you're trying as hard as you can to thermoregulate
but at some point if if you're unable to do that the body just completely shuts down.
[Reporter] When you see these women in Japan
know that before they get into their boat they will have been wearing ice vests, ice socks.
Slushy packets will be tucked into their uniforms.
And long before Tokyo they've been working on adaptation
which is what that thermometer pill they swallow is really all about.
And then you scan them somehow.
Yep so we've got little monitors and it's telemetric so it just transmits the data onto the monitor.
[Reporter] The goal is to make sure this kind of exercise imposes a type of thermal stress on their bodies
for about 45 minutes
at a core temperature of 38.5 degrees, about a degree and a half more than normal.
So if we have an athlete that heats up really quickly then we know that we can back off on
the work that they're doing so that we don't overcook them.
Forgive my crude question here but does the pill just get absorbed or?
It gets voided when they're done.
[Reporter] The precision of it all seems to be working.
Measurements of their effort and heart rates and how they feel show they are adapting.
An adaptation is really the only option now.
Hello Adrienne and The National.
And the national sailor Sarah Douglas who knows the sun and abnormally hot waters
will work against her.
is just one of many Canadian athletes earning sweat bragging rights
showing off their effort on social media.
She's been working out in an altitude chamber converted to a hot house in Toronto.
Halfway through my 40 minute bike I'm sweating.
Hot, it is 33.6 degrees celsius and 65 percent humidity.
[Reporter] Those working out like this routinely notice their heart rates dropping
as they get accustomed to it.
That will help.
Canadian Brent Lacitas is counting on it.
It's going to be quite hot, quite humid in Tokyo.
[Reporter] He's a wheelchair racer who's been to four paralympics.
His strategy for his events in Japan is a DIY heat chamber.
I'm going to be getting a humidifier that grocery stores use
so a fairly strong one and set that up inside my garage along with a heater.
[Reporter] For some paralympians in particular heat is even more challenging
because depending on their disability sometimes the capacity to sweat is diminished.
All distance athletes really are vulnerable.
41-year-old Melinda Elmore is a marathoner who competed in Athens in 2004.
Now she's off to Tokyo or rather Sapporo.
The marathon has been moved more than 800 kilometres north
in the hopes of cooler temperatures but danger still lurks.
In our minds as athletes we want to always do things at our very best in our best pace
and our best speed but the heat is legitimately a factor
and we need to back off 10 or 15 seconds a kilometre to adjust for the the pace.
How can you do that in the middle of an Olympic marathon?
When you look at the results in Doha, the world championships in 2019.
They were on the race at midnight.
The field was on average 15 slower than their personal best paces going in.
So then field will naturally adjust to that
and if you don't then you're going to pay a really heavy price.
[Reporter] Her plan to get ready is to do what doctors usually tell the rest of us not to do.
She trains at high noon in the interior of British Columbia.
Okay hang on one second Malindi our signal's breaking up a lot here.
Even just talking about the heat there in the heat is hard.
The computer's having some trouble keeping cool.
[Reporter] But we managed a few more moments to talk water
because to miss a drink station during this Olympic marathon would be serious.
So Malindi trains for the pickup bottles always on the right side
always a problem when you're left-handed.
[Reporter] Is there a level of stress to that act
especially given how important it is given the heat.
Oh yeah 100 percent, especially if people make sudden movements
it's really easy to trip and fall or have kind of a collision
and so you do have to be really strategic about how to actually get your bottle.
You know you can't go another 5k and not have your bottle
if you if you happen to miss the water station.
The countries privileged enough to have the training staff and resources
to prepare for the heat, it's hard enough.
So imagine those nations that don't, safety will be a serious war.
Is there part of you surprised that these games are happening in this month in Japan?
I guess a little bit.
I think with the way that the world is going now
and with what's happening with climate change, any summer olympics on any given day
it could be temperature extremes and so I think athletes and coaches need to be prepared for that.
[Reporter] They are trying, just like every aspect of the Tokyo games.
What the world is about to watch will be a test and rife with risk.