@aachen_hexagon Zone 2 can be very hard to stay in while running for people who are not runners. Basically, most people have shit running efficiency so any amount of running raises their HR out of Z2 pretty quickly.
Z2 adaptation is entirely different from Z4. To properly build Z2, you need to stay in that zone exclusively for extended periods of time, an hour is the absolute minimum. Many crossfitters seem to struggle with this concept and think you can do 20 mins of Z2 here, 20 mins there and it all adds up. It does not. Z2 adaptations, like any stress adaptation, happen when you create enough stress for your body to make an adaptation. If you walk at Z2 for 20 mins, you will never make an adaptation because there simply isn’t enough stress. It’s like doing a set of 1 back squat at 20% of your max. That’s just not going to effect any change, it lacks the proper stimulus.
Z2 requires two things: Actually staying in Z2 the entire time and working in that zone long enough to elicit a stress adaptation.
The first part can be challenging. Going by HR is not the most precise metric and wrist/light based HRMs are almost unusably bad. If you want to train in Z2 based off HR, get a proper chest strap HRM and link it to your smartwatch or phone. Next, HR varies by personal stress, time of day, outside temp, etc. You will also get something called “HR creep” where at the same power output level, your HR will go up and up over the course of a workout. The best way to do Z2 accurately is on an erg with a watts/power meter setting. Basing Z2 on power output is the hands down best way to train Z2 because it eliminates all the bad HR data.
If you must use HR (basically if you’re running or walking), try to stay closer to the bottom of the zone at the start of your workout to account for HR creep and try to do your workouts at roughly the same time of day, same time after meals, etc. To eliminate as much HR variability as possible.
The next thing is just staying in the zone. It can be very difficult to stay in the zone, you’re an athlete, you want to run fast! Just don’t. I don’t have the time to look it up now but there is some good peer reviewed studies showing that going out of Z2 mid workout is detrimental to your base aerobic training.
The other key factor is of course, time. To make Z2 stress adaptations, you have to go long enough in Z2 that low intensity becomes hard. Same as anything, the lower the intensity, the longer the time and vice versa. This means about an hour is the bare minimum for making training adaptations. If you want to really see results, shoot for more like two or three hours. Pick a good audio book or podcast and just walk easy. As you become more aerobically fit, your speed will increase but, and I cannot stress this enough, DO NOT PERSURE SPEED AS A Z2 GOAL. The exception is if you’re training for an endurance event or whatever but even then, the biggest issue I have with endurance athletes I train is they want to go hard on a Z2 day and they just blow up the training.
Z2 is not exciting. Z2 is boring as shit so just lean into it. Walk slow, enjoy the sights, talk to your mom on the phone, she misses you. Just don’t try to go fast or “get it done quick”