The WRU chairman is leading a team of 16 to the top of the Tanzanian peak to help raise £100,000 for the NSPCC's Full Stop campaign.
But after two days of climbing the 46-year-old Pickering admitted that he and his colleagues were "absolutely knackered".
Speaking from their campsite nearly half-way up Kilimanjaro on Friday, Pickering hinted for the first time that he feared not everyone in the team would make it to the summit.
"Everyone was in a pretty jovial mood when we left, but as we flew into Tanzania the size of the task ahead of us hit firmly between the eyes," explained Pickering.
"We were cruising at 17,000 ft and yet we still had to look up to the snow covered peak of Kilimanjaro - it was an awesome sight. That instantly turned what many of us thought was going to be a bit of a jaunt into a far more serious exercise.
"There is an easy way to climb Kilimanjaro, but our leader, Lt Col Dicke Davis, chose the army route for us and that meant we spent the first day clambouring virtually on our hands and knees through the rain forest.
"We did nine solid hours to reach our camp. At the end of it we just put up our tents, went straight to bed and didn't even contemplate eating.
"I don't think I have ever been so exhausted in my life. Even JPR Williams found it tough going!
"It took us two days to reach 2,180 metres and the worry is that with fresh snowfall at the peak in recent days the climb is only going to get harder and colder.
"But we haven't come all this way, or put in so much training, to be beaten by this moutnain. We are all determined to push ourselves to the limits to raise the final £30,000 we need to break through the six-figure fund-raising barrier."
Pickering and co were told by Lt Col Davis just before they left last Monday that they faced a diffiuclt task because their route had to be changed following a series of recent deaths on their origianl path.
"Three people had been killed recently taking our initial route up the mountain so we were forced to factor that into our planning. There was a problem with some rock falls and we decided to alter our plans accordingly," said Lt Col Davis.
"We are still aiming to reach the summit (19,335 ft or 5,895 metres)in five days. It is turning out to be exactly what I promised them all - the most physically demanding activity that 99% of them have ever undertaken in their lives.
"To be honest, I'm not sure that everyone is going to make it to the top, although that our collective goal. We started as a group and we want to end as a group.
"As well as being physically challenging, there are also moments of potential high risk and danger. This is no easy ride and as we climb higher so the risk of altitude sickness will come into play."
While temperatures are high at the bottom of the mountain, by the time the climbers reach the summit the evening temperatures can plummit well below zero.
Principality Stadium will host the UEFA Champions League Final in six weeks' time. WRU chairman Gareth Davies, Football Association of Wales chief executive Jonathan Ford and Ambassador Ian Rush joined young sports fans at the trophy arrival at the venue to celebrate the magnitude of the event on Saturday 3rd June (kick-off 19.45).
British and Irish Lions captain Sam Warburton is looking forward to bringing together players from Ireland, Scotland, England and Wales for the biggest challenge of their careers - a series against world champions, New Zealand.
For the fifth year running, Wales referee Nigel Owens will be in charge of proceedings at Judgement Day V at Principality Stadium. It promises to be 'extra special' for the Wales' favourite ref, as he will be making his 150th appearance in the league.
There will be no shortage of inside knowledge from Bowl Finalists Caerphilly and Amman United when they face each other on Sunday at National Finals Day. Caerphilly hooker Rhys Cleverly knows the Principality Stadium pitch better than most as a matchday groundsman, while Amman United can look to Wales' record try scorer Shane Williams for some helpful advice.
Two hundred and 40 teams competed in the inaugural Urdd WRU 7s held at Pencoed last week with Welsh internationals Steff Andrews and Jasmine Joyce impressed with the talent on display, as was Urdd chief executive, Sioned Hughes.
The countdown is on for Judgement Day V as tickets for the big day at Principality Stadium soar through the 50,000 mark. Players and coaches alike are bursting at the seams to play in the double header with Dragons coach Kingsley Jones claiming there is a 'real buzz' about the event.
WRU TV went behind the scenes when the four regions got together to test their skill set for the BBC's Scrum V Live rugby show, at the WRU National Centre of Excellene in the build up to Judgement Day V. Blues' Matthew Morgan was one of the stars of the show while the Dragons' Cory Hill proved a surprise package...the full set of results will be revealed on tv screens on matchday
Wales assistant coach Richie Pugh is confident his side can cause a few headaches in the Hong Kong Sevens this weekend. In a tough group, Wales kick off their campaign against New Zealand on Friday before playing Japan and Fiji, who are chasing their third consecutive Hong Kong title, on Saturday.
Bedwas had to overcome a stubborn Carmarthen Quins side before winning the Foster's Challenge Cup final in Bridgend with a 23-18 victory. Bedwas captain Nicky Griffiths pays tribute to his side who have claimed the club's first piece of silverware in the modern era.
Team coach Brett Davey is aiming to keep his unbeaten run in cup finals at Principality Stadium intact when his side take on Amman United in the WRU Bowl final, after he guided Caerphilly to a 20-14 win against Cilfynydd in the semi-finals.
Penallta are hoping to go one step further than last season when falling to Bedlinog in the WRU Plate Final. After a titanic struggle against Nant Conwy, they have given themselves a great chance, after a hard fought 18-13 semi-final victory.