Former professional racer here (USSR), former world champion (junior TTT).<p>The article describes a methodology (high volume, low intensity) commonly practiced by many teams in the USSR, especially my team who took it to the next level supported by a group of scientists and researchers.<p>Prior to hiring, every candidate (I'm talking about my team) went through intensive testing. A lot of guys (but not all) were sent home based on low VO2Max numbers.<p>I was 17 when I got a call and tested at low 60 VO2Max on my first test and was offered a ride. I came from a completely different training methodology based around short, high intensity intervals. Within a year, my VO2max moved to high 70 and eventually settled around 80- mid-80 depending on various factors during the season. I've seen this growth in others, sometimes even more dramatic.<p>To give you an idea, we clocked around 40,000 km per year of mostly low intensity training. A typical training day was made up of 3 rides: 40 km in the morning before breakfast, 3-5 hour ride (depending on the cycle) after breakfast, and another 40 km ride in the late afternoon. We lived on the bikes 11 months a year.<p>We were often told to pull out of dog fights on the climbs during a race to keep that low intensity in check and just ride tempo far away from threshold (although we used heart rate monitors in training, crude, early version of them, this wasn't possible in a race because the signal was sent to a team car, nothing was displayed on a bike). Not knowing your exact heart rate, we had to go by feel and to this day I can quite accurately tell what my heart rate is at different level of intensity.<p>For high intensity work, we practiced 20-25 km intervals at race or somewhat higher than race pace intensity, usually 4 or 5 of them per session, pretty much mimicking a 100 km TTT which is what our specialty was at the time (Olympic gold was important for propaganda).<p>In 8 years of its existence, that team went from an unknown startup to delivering several world champions. When the Soviet Union collapsed, those who survived the crash managed to make it to the west and raced in pro peloton. One guy in particular, my former teammate, did well in the Giro and the Tour. Others, who went through the similar system, went on to win Grand Tours and major Classics.<p>That is to say - the methodology has merit even though a lot of literature suggests a different kind of training.