The day arrives and we check out of the hostel. Both of us are unusually struggling to manage our usual quota of free pancakes for breakfast. Pre-match nerves or the street vendor papas fritas from the night before? We're not sure.

We walk down to the tour office and meet the others on the trip and the guides. We all wait for over an hour for the office to open. Not a great start. We get in expecting to pick up all the gear we're borrowing for the trip but we find the office bereft of gear and we're a little puzzled.

We're introduced to our guide Silveirio and are told that our taxi van is waiting for us a block up the road. We find the van and all our gear in. Next job is to sort it out. Boots, trousers, crampons and gaitors are strewn over the pavement as the guides and tour operator decide who needs what. Our gear isn't passed to us just thrown into the van and we get in. Should be interesting to see what we get.

There are five of us in our van. Manu from Japan who is along for just the first day and Hege (Norway) and Oscar (Bolivia) who like us are on the 3 day summit attempt.

The taxi takes us on a neck wrenching 2 hour drive through El Alto to the base camp refuge. The hut is pretty good and with lunch inside us we set off to the glacier for some winter skills and ice climbing. The walk to the glacier is easy but with the altitude our lungs are quickly working overtime.

We practice ascending and descending steep ice until the guides are happy we've all got it, then top rope some vertical ice and head back for dinner.

The next day we make the 3 hour trip up to high camp. The major problem with this is we're carrying all our gear and the high refuge is at 5100m. The going is slow and we stop to rest many times knowing that there is no rush. The gravel and rocks turn into snow which has no steps kicked into it and resembles a groomed piste. The decision to wear our trainers was ill-advised and the slippy conditions ensure the going is tougher than necessary. We meet the group who attempted the summit that morning. All the 2 day attemptees had failed but the 3 day group had faired better. This gave us some confidence that it was possible.

We reach the high hut with our lungs ready to give in and our heads pounding with headache. We have lunch and dinner interspersed with a snooze and set about trying to sleep knowing we're up at 12 midnight for the summit.

Midnight comes and we both get up surprisingly quickly, get our gear sorted and have a breakfast consisting of water for me, coca tea for Helena and a breadcake each. We step out of the hut into a moonlit night, great conditions, and set off in formation Silveirio, Helena and then me. It is cold but the gear we have seems to the doing the job and we quickly start to warm up. Our pace is slightly quicker than we expected and we make it the first rest stop at 5500m on time.

By this time the mental games of such an effort had already started in my head. Thoughts of giving up or it's too hard were already gnawing away at my resolve. To combat these persuasive demons I would just concentrate on the thwack, crunch, crunch of my ice axe and crampons. Counting the blows 1, 2, 3 over and over again. We came to a steep section of soft powdery snow which we zig-zagged up. The gradient and snow condition was such that we were starting to get nervous of avalanche or a slip as kicking steps into the instable snow didn't give us much confidence. We reached to top of the steep section with much relief but also in the back of our minds knowing we would have to return this way.

The track eased now and we had less use for our ice axes. Slowly we plodded gently up and around the mountain to meet the summit ridge. The altitude though didn't ease up and we were constantly battling the demons who promised sleep, rest and warmth back at the hut.

Clouds came in turned off our natural moonlight. The shadows now provided even more doubts as we discussed what we thought were large cornices above us and how close we were to the black holes on our left and right.

Snow started to descend as we met teams in front returning from their night summit success. With congratulations and words of encourage we marched on slowly and weary of the turning conditions.

This section up to the summit ridge was where I had my worst moments. Feeling heavy legged, lungs working overtime but unable to satisfy my needs. My heart beat pounding and throbbing through a headache behind my forehead. I just concentrated on Helena's heels in front trying to keep in time with her rhythem whilst counting my own footsteps in sets of one hundred. I think I counted to one hundred eight or nine times before we reached the summit ridge.

After a good rest which seemed like only a few seconds we started the steep climb to the ridge. With only 88m of ascent left I started to feel sure we would make it, Helena however was struggling. Once on the ridge with rather steep drops either side we needed to rest more often than before. Sometimes only a few steps would seperate our rests. Helena seemingly needing them more than I right now. Silveirio patient but at the same time constantly egging us on must have had doubts. We all knew the conditions were still getting worse. Although the sun was starting to make an appearance on the horizon the soft powdery snow was still falling and with every new flake our chance of returning safely deminished.

With only a few yards left we stopped again when it seemed easier to continue and finish this hard slog. With some extra motivation from our guide we kicked on and exhausted sat on the summit of Huayna Potosi at around 6:45am.

Quickly we took a few photos and conscious of Helena's symptoms and the still falling snow we started back down the ridge. I was leading now and path although easy to follow was trickier with the new snow. Off the ridge and on to easier ground the white out conditions made the track disappear at times and I was struggling to keep to it. It's never easy is it?

Once we were down a few hundred metres conditions improved. We left the cloud and snow behind and could now take in the beauty of the layered ice shelves, the crevasses and rolling snow fields.

We made it back to the high camp at around 9am. Food was available but neither of us could eat a thing. We took on some water and started to sort out our gear ready for the two hour trip back down to mountain to the base camp. The walk back was hard and very slow and we struggled to maintain a pace above that of a snail, too tired to realise what we'd achieved, just thinking about a bed and sleep.