It is a common sentiment that high-intensity workouts are necessary to see results. However, this sentiment – which is very popular among Gen X’ers – can lead to overtraining, injury, and stagnated performance. CrossFit methodology describes 3 energy systems that vary by the fuel the body uses to generate energy, duration, and, by necessity, intensity. The ability to excel within all three energy systems and adapt quickly through training among them in the same session creates a solid foundation upon which to achieve optimal performance in whatever sport or activity one undertakes.
Zone 2 training refers to activities where the heart rate settles between 60-70% of one’s maximum heart rate, which is a pace that is considered “conversational”, but still clearly working. Zone 2 training targets the “Oxidative” energy system, which primarily uses oxygen as the energy source. This type of training is gaining traction among athletes, coaches, and health experts for its potential benefits for endurance, energy efficiency, recovery, and long-term performance.
Many endurance athletes rely on Zone 2 as the cornerstone of their training, but power athletes and everyday fitness enthusiasts can also gain significant advantages. Whether your goals are running a marathon, excelling in strength-based workouts, or simply improving health, Zone 2 training might be the missing link in your routine.
Understanding the Heart Rate Zones
There are five heart rate zones, each representing a different level of effort. Zone 1 is very light, Zone 3 to Zone 5 cover moderate to maximum intensity, while Zone 2 is that steady, conversational pace. Although formulas like “220 minus age” are often used to estimate maximum heart rate, they can sometimes be inaccurate, especially in older, fit individuals. Formal exercise testing provides the best estimate of maximum heart rate. Since most of us do not have access to an exercise physiology laboratory, some easy ways to estimate heart rate zone 2 are maintaining the ability to carry on a conversation (shorter sentences as compared to a narrative) or the ability to maintain nasal breathing during an activity.
Why Zone 2 Matters
For marathoners, triathletes, and cyclists, “oxidative capacity”, which is the ability to use oxygen as a fuel source, is essential. Zone 2 training helps to build this oxidative capacity—this helps the athlete sustain longer efforts. It creates the aerobic base that supports the higher intensities required on race day, making it indispensable for endurance success.
Power athletes, such as sprinters, weightlifters, and CrossFit enthusiasts, often thrive in Zones 4 and 5, where carbohydrate is the primary fuel source for the short bursts of energy required for these activities. However, including Zone 2 sessions helps the power athlete to build their capacity to utilize oxygen for fuel, which may help build resilience, improve cardiovascular health, and increase energy efficiency. There is evidence that incorporating zone 2 training into an athlete’s overall program can potentially support faster recovery between explosive efforts and promote overall longevity in sport. Even athletes who prefer high-intensity workouts can notice improved performance when Zone 2 becomes part of the mix.
How to Incorporate Zone 2 Training
Adding Zone 2 doesn’t mean overhauling your current routine. A few sessions per week of 30 to 60 minutes, whether through jogging, cycling, rowing, or even brisk walking, can make a big difference. Endurance athletes may devote more time, while strength-focused athletes can use it as active recovery or conditioning work. The key is to keep your heart rate in the conversational range and stay consistent. Over time, you’ll notice improved stamina, better energy balance, and more efficient workouts across the board.
Zone 2 training may not be flashy, but its impact is undeniable. It builds a strong aerobic base, supports energy efficiency, and contributes to overall health and performance. Whether you’re a long-distance runner, a high-intensity athlete, or someone simply looking to improve fitness and longevity, adding Zone 2 could be the missing link your body has been waiting for.
For women in particular, hormonal shifts throughout life can affect energy systems, recovery, and performance outcomes. To learn how to structure your training for long-term success, connect with Dr. Carla DiGirolamo, a pioneer in women’s performance endocrinology, who specializes in helping active women reach their peak potential from puberty through menopause.