For 2017 I did Novice mountain bike races and I did ok. When I tried to do longer distance events, the 6 Hour races, I struggled. I didn’t train enough in zone 2. When you’re looking at a 6 hour event. You can’t use anything above Zone 3. Zone 4 is your 20 minute all out effort. This is where you are during a FTP test, and this is where I did my training during 2017. I did mostly Zone 3 sessions with some Zone 4 mixed in. I threw in some shorter intervals in Zone 6, but none of that got me ready for a 6 hour race.
In my first 6 Hour race at Hueston Woods, I don’t have any heart rate or power data, I was just going to get a feel of this type of event, but I was done after 2 laps and 1 hour 35 minutes. I also had a flat tire, but I think I was done at that point anyway.
My second 6 Hour race was at England Idlewild in Kentucky. I don’t have much data from that one either (it’s important to at least get heart rate data!), but I did 3 laps at 2 hours and 44 minutes and I was cramping so bad that I had to stop there. I’m pretty sure that I had to do too much Zone 3 and 4, my muscular endurance wasn’t good enough, and I didn’t hydrate well. Lots of lessons learned.
The goal of this endurance training is to increase the power that you produce in zone 2, so your heart rate doesn’t go high enough into anaerobic or muscular efforts. In other words, you want to use your heart and lungs instead of muscle power.
The muscles have to laugh at the effort in Zone 2. That means strength training. Early season strength and on the bike force training builds muscles up and gets them ready. I have been doing 2 sessions per week of Maximum Overload. Which is a lot of leg, back and core work. The highlights of the leg work are deadlifts and weighted walking lunges. During the season, I will try to continue to do this once per week.
Muscular endurance can be trained. I found out during 2017 that my muscles will go around 1 to 2 hours before they give up. I can increase that by doing low cadence, force training on the bike.
The body stores around 2,000 calories of glycogen (sugar) in the muscles and liver to use as immediate fuel. So if you are going really hard then you will run out of energy at some point, probably around the 2-3 hour mark. This is when a lot of people bonk or hit the wall.
In Zone 2, the body is using this sugar, but also body fat for energy. Even on a thin person, the body has a large amount of fat stored. Zone 2 uses this fat storage, and the more you train in zone 2, the more efficient the body becomes at burning fat for fuel. Even at a resting state, the body gets accustomed to doing this, which is a bonus for some of us that want to reduce our body fat percentage.
For the endurance races that I will be doing in 2018, I have a lot of training to do. A large part of that training will be in Zone 2. For me, that’s between 120 and 170 watts. This will put me in that fat burning mode that I will need to reduce body fat so that I can climb better, and it will train that all-day engine that I will need to be able to fall back on when I’m tired during a race. Maybe next time I will be able to go longer without having to give up completely.