When we train in altitude, we need to follow some principle, that is common for African people like for European or American people :
a) The first effect of training in altitude is TO IMPROVE THE AEROBIC POWER. So, altitude is not DIRECTLY effective for those distances NOT DIRECTLY DIPENDING ON AEROBIC POWER.
b) Which are the event DIRECTLY connected with the AEROBIC POWER ? Are 5000 / 10000 / HM. For those events, ALTITUDE TRAINING IS A DIRECT MEAN OF TRAINING.
c) For shorter distances (800 / 1500) or longer distances (Marathon), ALTITUDE TRAINING HAS EFFECT ON... THE SPECIFIC TRAINING, but not on the performance. In other words, training in altitude allows the athlete in having more basic support for developing (may be at sea level) the SPECIFIC SPEED ENDURANCE (that is in lactic area for short distances, of course over the Threshold, while is in full aerobic area for marathon, under the Threshold).
d) Methodologically speaking, in altitude we cant use the same system we use at sea level. We MUST train with high volume,limiting lactic workouts. We cant use, for example, SHORT RECOVERY, because the REMOVAL of lactate is slower, due to the lack of Oxygen. Or, if we want to maintain the same recovery time, we need to run slower.
The normal rule is as follows :
1- Tests very short and fast (100-300m) : a little bit faster than at sea level, same recovery time
2- Tests of medium length (400-600m) : same speed of sea level, recovery time 3/2 of the normal time (for example, if we use 2' at sea level, in altitude becomes 3')
3- Tests for Aerobic Power (1000-3000m) : pace slower (about 97% of the speed at sea level), and recovery time 3/2 of the normal. For example, if at sea level you run 2000m in 6' (360", 3% is about 11"), at altitude of 2000m you run at 6'10" / 6'12".
4- Long continuous run : the difference of pace can be about 5" - 8" per km for athelets living at sea level, after a period of adaptation, while is under 5" for people living in altitude. For example, last year at the end of May, Florence Kiplagat ran in a hilly road between Iten and Eldoret (Kaptuli) 15 km (measured with GPS) in 48'47", that can mean like 47'30" at sea level.
5- When the pace is moderate, there is no difference. For example, an athlete able running in 28' (10000m) or 2:10 (Marathon) can run 20 km at 3'45" pace at sea level, exactly how in altitude.
For having some effect of training in altitude, we need to go higher than 1800m, also if for athletes never going in altitude before already 1400m can have some effect.
We need increase the level of the altitude using several periods : if the first period (normally we use 3 weeks for athletes living at sea level) is at 1400m (South Africa, for example), a second period can be a St. Moritz (1800) and a third period in Sestriere (2000m), for having more physiological stimula and consequentely more supercompensation.
Big risk is to run too fast in training of LACTIC CAPACITY, connected with the LACTIC POWER. Since there are different ways in terminology, LACTIC POWER is,practically, the PB of 600m (for example, 1'16"), and LACTIC CAPACITY is 3x600 in 1'21" with 7'-8' recovery.
In 1988, the team of East Germany went to Sestriere for preparing OG of Seoul, with their best group of sprinters. Among them, there was the World Champion of 400m of the previous year, Schoenlebe (winner in Rome in 44"33). I saw one incredible training of Lactic Capacity : 3 x 500m with 7' of recovery, in 59"7 - 59"5 - 59"6 (the official World Best performance was 60"02 !). I was sure he could win Olympic running under 44". Instead, he ended his career going out in qf running 46"60 !
Only several years later, studying the lactic reaction in altitude with a group of French scientists, we discovered that SO HIGH INTENSITY FOR A LACTIC WORKOUT COULD PROVOKE A REVERSAL OF THE POLARITY OF THE MEMBRANE. Practically, the athlete is no more able to eliminate the rubbish rimaining in his cells, and the cells cannot receive the right nutrition. In this case, the sensation is to have legs always very heavy, a feeling of "chocking", like a stagnation of lactate inside. The problem is that, ecceeding in this type of training, this situation becomes irreversible, and the athlete is no more able to have any type of endurance for ever.
Finally, my advice for all the athletes going to altitude is : go for running VOLUME, not INTENSITY. In any case, you can have advantage under Aerobic point of view, and don't risk any mistake.