Before thinking about tackling a trek to the summit of Kilimanjaro you do need to consider what is involved in the challenge. Exodus classify it a Grade C/D walk and say "The summit attempt is D grade because of the high altitude and the level of physical effort needed. Many clients find the summit day the toughest physical challenge of their life. The rest of the trek is C grade more as a consequence of the high altitude and extended wilderness camping than the difficulty of walking."
We have to say that we did not find this trek as demanding as others we have done. Yes, the final day is challenging but the very slow speed, expert leadership and support of team members all help. If anything the psychological anxiety in the few days before the summit was the biggest pressure.
On the other hand, individuals' reaction to altitude is very difficult to judge and can even vary from day to day. We were both fortunate not to have suffered physically from altitude at any point. However, one of our group did suffer the classic signs of altitude sickness and had to descend at the end of day 4. To have attempted to continue was simply not a viable or safe option.
One final word of warning - beware of jokers like our chief guide, Makeke! When we arrived at Stella Point, some 45 minutes from the summit, and had a hot drink he started singing 'Let's Twist Again' ... and guess who joined in the dancing?! Not the best thing to try at nearly 6000m with more walking still to do!!!