Why Zone 2 Training is Essential

Training zones can be guardrails to our training that provide direction, intention, and purpose to our efforts. As I’ve talked about in past articles, using training zones can lead to a variety of advantages as athletes.

Utilizing them can help us to:

Interestingly, the most often neglected area of training is Zone 2 training. This is the foundation of our fitness, acting like the broad base of a pyramid. This is where the bulk of beneficial endurance adaptations happen, in addition to unlocking more room to develop power and speed on top of it.

What is Zone 2?

To put it casually, this is the range of effort that allows us to carry on a conversation fairly comfortably. It’s the range in which your heart rate and power are low enough to maintain it for extended periods of time and equates to around 70% of max heart rate. This is the more oxygen-dependent energy system; zones 1-2 rely more heavily on fat as a fuel source and oxygen to break it down.

Zone 2 keeps you below an effort that requires a shift in fuel sourcing. It’s one of the most reliable fuel sources long term but requires a lower effort to do so.

Why Zone 2 Training is Important

As touched on earlier, Zone 2 is that spot of effort that basically teaches your body how to break down fuel effectively, use it effectively, and become more efficient. Meanwhile, you are essentially building and improving mitochondria (”powerhouse of the cell”), which creates an overall more efficient energy system.

The problem is that it’s quite easy for most to skip over altogether. Why? It requires going slow.

Unless you are intentionally keeping your pace low, you’re likely to jump up to Zone 3 or higher unknowingly. Zone 2 just doesn’t feel hard, or like you’re “working”. That alone leads many amateur athletes right past it and into that heart-pumping, leg-burning, area of satisfaction. While there is a time and place for high-intensity efforts, dishing them out every single ride is not advantageous to long-term development.

The issue is that you’re brushing over the area that contributes most to overall cardiovascular development. Zone 2 training props up the rest of your training like a pyramid, as I referenced. The broader and stronger the base, the higher you can build on it.

Fueling Guidelines for Zone 2 Training

We all know the importance of carbohydrates for optimizing training. That buck doesn’t stop with Zone 2 training, however, there are some considerations for how to fuel appropriately.

I fuel the longer, endurance days with “real food” that are a bit more complex and sustaining. They come with a little “processing fee” that leads to a slower breakdown and don’t keep my energy spiking and falling like a roller coaster. I might pack a Betty Lous, banana, Maurten SOLID, or simple bar. I pair that with a great hydration drink mix to stay on top of electrolytes, such as Skratch Labs, Neversecond, or First Endurance. Then, I work my way down to the simpler carbs as I get deeper into a workout or ride when I just need fuel.

If you aren’t able to ride significantly longer, don’t fret. You can still optimize your training with zone 2 for the best benefit.

Here is a gameplan:

<60 mins: you shouldn’t need much more than a good hydration drink mix (ie. Skratch Labs). Your body has enough energy to adequately fuel you for an hour or less and staying away from high-calorie intakes can help enhance the endurance effects of a quick zone 2 ride.

60-90mins: for this length, you can add a lighter 20-30g of carbs every half hour in addition to your hydration. A hydration drink mix (like Skratch or Neversecond) and a snack (like Untapped Waffle) can do the trick.

90-120mins: as you approach the 2hr timeframe, you can begin to run through a good bit of stored glucose even though fat is the main proponent. To get really good quality out of your session and maintain zone 2 power, supplementing with carbs can be advantageous. Aim for 20-30g every half-hour along with hydration. Again, bars and “solids” may be ideal here along with some clean Endurance Tap gels and/or simple sugars later.

120mins +: any longer rides over that 2hr mark will tap into your stored glucose (glycogen) regardless of effort. Thus, the longer you plan to go, the more carbs you should consider taking on early in the ride. This is where you won’t want to skimp on carbs per hour because it allows you to maintain a steadier output for longer.

You should aim for 60-80g an hour. A “heavier” drink mix may come in handy, such as Maurten’s 160 or 320 and Neversecond’s C90. Then, a mix solid food and quick bites can help maintain that intake, like SOLID, Skratch rice crispy treat, or Skratch Labs Chews. Another option is to opt for simpler food (like chews and gels) but more often if you have trouble eating – even during these long ones.

In closing, this isn’t meant to dissuade you from doing high-intensity…but rather to seriously consider swapping some of those rides out with lower-intensity zone 2 rides. The lure of a Zwift crit is enticing, but try doing some deliberate aerobic rides and/or adding some long ones in on the weekend. Watch that fitness grow...

Photo credit: Callie Horwath