Hi, I am 55 years old (so recovery may be an issue) and in a week I'll go on our yearly mountain trip with my club.

We do 100k rides with up to 3000 altitude meters every day. One of the climbs every day counts for the competition. Total time is measured over these competition climbs.

Day 1 Day 2 Day 3 Day 4
Climb 6.5 km 7 km 23 km 5 km
Grade 8% 9% 7.4% 10%
Distance 71 km 95 km 112 km 112 km
Total altitude 1780 m 2350 m 3200 m 3370 m

What is the best strategy to achieve the shortest possible total time for the 4 competition climbs? Obviously I should not spend too much effort on the climbs that are not part of the competition, but it probably isn't too smart too go all out on day 1 either. Also notice the long climb on day 3 (Stelvio), a lot of time could be gained/lost on that day.

Any recommendations on how to best pace myself for these climbs would be appreciated.

Some additional info:
Age: 55
Length: 1.83 m
Weight: 78 kg
Max heart rate: 178
Lactate threshold 1: 159
Lactate threshold 2: 170