The presenter looked terrified as he took the plunge on the wire on London’s Southbank which is suspended 35 metres off the ground.
He failed to keep his cool as he was sent hurtling along the zip which is said to be the fastest in the world with those riding it reaching speeds of up to 30 miles an hour.
Alex looked nervous as he stood in his harness at the top of ride shortly and tentatively made his way down the steps before taking off.
“Oh my god, oh my gosh!” Alex was heard exclaiming as he walked down before screaming as he took off.
The moment got even better as Alex’s harness appeared to turn and he seemed to be careening down the zip wire backwards.
“I’m going backwards!” he shouted as he tried to calm down his nerves by singing.
The broadcaster appeared to loose momentum as he ended up awkwardly in the middle of the wire and concluded: “And that’s how you do it.”
He held onto the harness with one hand and a selfie sick filming his hilarious descent.
Alex was not the only member of the Good Morning Britain team member to take to the zip wire, news reporter Richard Gaisford also had to do it after mocking Alex earlier on in the show.
Compared to Alex’s plunge, Richard remained cool as he flew through the air and gave a running commentary of his flight through the air.
The scenes come in contrast to the more serious segments today, one of which saw Eamonn Holmes clash with a guest over big game hunting.
Good Morning Britain airs weekdays on ITV at 6am.