If you’ve ever signed up for a charity ride, fondo, or other endurance event and wondered how you’d fit in all the training, you no doubt rejoiced upon learning about the benefits of high-intensity interval training. Big fitness! More speed! In half the time!

Whoa. Slow down. Because if you don’t keep your training mellow—at least some of the time—your progress will sputter to a halt. Therein lies the imperative for base training, the process of gradually developing a platform for your fitness.

“Base training is the foundation upon which everything else rests,” says Danny­ Suter, USA Cycling Level 2 coach and founder of the Boulder Performance ­Network. When you build endurance, eventually you can get more out of higher-­intensity riding and a heavier training load. “Riders who go straight into speed work can get fast on the bike,” says Hunter Allen, coauthor of Training and Racing with a Power Meter. “But they won’t have aerobic endurance, so their fitness lasts just a few weeks before they slow down.”

When you ride for two or more hours (or less for new riders) at a steady pace—a typical base ride—your body responds with changes that allow you to use more oxygen and burn more fat as fuel, says coach Joe Friel, author of The Cyclist’s Training Bible. For starters, these rides build more ­capillaries, the tiny blood vessels that deliver oxygen-rich blood to your muscles. Your mitochondria—the parts of your cells that produce energy—also multiply and enlarge. And you churn out more enzymes that help turn stored fuel into energy. The result: You can ride faster and longer.

Finally, and maybe more important, base-building rides tend to be the most social and fun, so you can just enjoy being on your bike, hanging out with friends, and recharging your batteries without worrying about going hard or being dropped. “Too many riders are in a hurry to get right to the high-intensity work,” says Friel. “They usually burn out by May.”

Strong base building starts with solid rest. “Everyone needs a break from hard efforts and structured riding so they can repair and recharge,” says Suter. Take a few weeks after a period of intense riding or your most recent goal event to rest, cross-train, and just catch up on life. “Back off enough to recover, but not so much that you completely lose fitness,” says Suter. Building a solid base also requires that you work on other key fundamentals, like general strength and technique, which are essential for long rides. Here are some guidelines.

Keep it steady
You’ve likely heard of long, slow distance rides, or LSD. Don’t be misled by the word slow. We’re not talking about a walk-on-the-pedals recovery ride. In fact, you should spend the majority of an LSD ride at what coaches call Level 2 intensity, or roughly 65 to 75 percent of your maximum heart rate or perceived effort. The key is to keep your intensity steady—avoid coasting and hard efforts, says Suter. A few weeks of this builds a big aerobic engine, Friel says. If the weather’s bad, you can ride for an hour or so on the trainer. Important note: “Long” is relative. Depending on how much you ride, it can mean ­anything from 90 minutes (or an hour on an indoor trainer) to multiple hours. About 40 percent of your weekly training time should be at Level 2 during base building.

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Be stroke savvy
“Work on your pedaling to develop a consistent force all the way around,” says Friel. One surprising way: Hit the trails. “Mountain biking creates a smooth pedal stroke because you need to keep your force even so as not to skid on loose terrain,” he says. Otherwise, spend two or three rides a week aiming for a cadence of about 95 revolutions per minute.

Use force
Riding a bike for significant lengths of time requires strength and power. Designate one or two rides a week for seated, lower-cadence hill climbing. “Staying in the saddle on all climbs builds hip and knee strength and improves power,” Friel says. If you’re over 40, female, or a skinny, small rider, you may need to build more lower-body muscle mass. Supplement with moves that simulate pedaling action, like squats, leg presses, and step-ups, says Friel.

Give it time
There’s no magic number for how long a base-building period should last. A good ballpark is six to 12 weeks. If you have a heart-rate monitor and power meter, you can measure when you’ve built up Fyour base. Monitor your “efficiency factor,” a measure of the output (watts) you produce for the input (heart rate), says Friel. To find yours, divide your power number for a given ride by your average heart rate. The absolute figure doesn’t matter; you want to see an upward trend. “When it stabilizes, you’re ready for the next training phase,” he says. If you prefer to keep your rides unplugged, you can use intuition to estimate when you’ve built a solid base. On rides in similar and not extreme conditions, your speed should improve at the effort you use for your LSD outings, and those rides should feel easier. When you feel like you’re not making progress (that is, you’ve plateaued), you likely have built your base.

Be patient
Many people believe that base training must be done at low intensities to work properly, and that hard efforts will undermine it and send you back to square one. While high-intensity­ interval training won’t build general endurance, it can improve some markers, like V02 max. The takeaway? An occasional spirited effort won’t erase your base, but be sure to build it gradually so you don’t peak too early.

BASE-BUILDING BASICS
This sample training week incorporates all the fundamental elements ­mentioned above. Use it for four to six weeks (or until you feel you’ve hit a plateau), increasing­ your long rides by about 15 minutes each week, before embarking on an event- or race-specific training plan.

DAY WORKOUT TIME INTENSITY
MON Off or easy cross-training 30-60 minutes Easy
TUE Hills or strength-training About 60 minutes Moderate to hard
WED Long, slow distance (LSD) ride 90-120 minutes Mostly easy; can push to moderate on climbs*
THU Hills or strength-training About 60 minutes Moderate to hard
FRI Off or easy cross-training 30-60 minutes Easy
SAT LSD ride 90-120 minutes Mostly easy; can push to moderate on climbs*
SUN LSD ride 90-120 minutes** Mostly easy; can push to moderate on climbs*
EFFORT
GUIDE
EASY
You're not breathless and can talk in full sentences.
MODERATE
Your breathing is heavier, but you still can have some conversation.
HARD
Talking in more than short sentences is not happening.

*Work on high-cadence spinning for most of the ride (@95 rpm)
**Can go longer. But keep it steady.

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selene yeager
“The Fit Chick”
Selene Yeager is a top-selling professional health and fitness writer who lives what she writes as a NASM certified personal trainer, USA Cycling certified coach, Pn1 certified nutrition coach, pro licensed off road racer, and All-American Ironman triathlete.