As a personal trainer and health coach, I get asked all the time about the best workouts, exercises, or supplements for longevity and health span. Now, of course this answer depends, but I always say that good health starts with a foundation of cardiovascular fitness. Sure, strength matters. And yes, you should train balance. But the biggest lever for living a healthy, robust back-half of your life? It’s probably your cardiovascular system.
Now, you don’t have to train for a marathon or become an endurance athlete, but if you want the energy to play with your kids or grandkids, or just power through life without feeling wiped out, training your cardio system is non-negotiable. Let’s dive in.
How Do You Know If You Need More Cardio?
While I would say everyone should be doing some form of cardio training, here are some red flags that you have a weak cardio system:
- You get winded easily. If climbing stairs or playing with your kids leaves you breathless, your cardiovascular system needs work.
- Slow recovery after workouts. If your heart rate takes forever to come back down, your aerobic fitness could use a boost.
- Low energy levels. Struggling with fatigue? Cardio can improve oxygen delivery and help you feel more energized.
- High resting heart rate. A consistently elevated heart rate at rest can indicate poor cardiovascular health. (See below for benchmarks.)
- Struggles in sports or daily activities. Better cardio means better endurance, whether it’s surfing, tennis, or just keeping up with life.
The Why: Benefits of Cardio Training
Cardiovascular training strengthens your heart, improves endurance, and lowers your risk of heart disease and diabetes. It also enhances brain function, boosts mood, and helps with weight management and recovery from strength training. The better your ability to get oxygen and blood to your tissues, the better you will feel and the longer you will live.
A weak cardiovascular system makes everything harder—walking up those stairs, chasing down the kids, or just getting through the day.
3 Simple Tests to Measure Your Cardio Fitness
1. Resting Heart Rate (RHR)
While not a complete picture of cardiovascular health, your resting heart rate (RHR) provides a quick snapshot of how efficiently your heart is working at rest. Generally, a lower RHR (fewer beats per minute [BPM]) indicates better cardiovascular fitness.
Benchmarks:
- Red flag: Over 70 BPM
- Good: 60–70 BPM
- Great: 50–60 BPM
- Excellent: 40–50 BPM
2. Heart Rate Recovery (HRR) Test
To get a better gauge of your cardiovascular fitness, measure how well your heart recovers after an intense effort of exercise.
- Perform an intense activity and reach your peak heart rate.
- Rest for 60 seconds, then measure your heart rate again.
- Subtract the second number from the peak heart rate—this is your HRR score.
Benchmarks:
- Red flag: Less than 20 beats
- Good: 20–30 beats
- Great: 30–40 beats
- Excellent: More than 40 beats
3. VO2 Max
VO2 max is the gold standard test for cardiovascular fitness, but it can be tricky to measure unless you have fancy lab equipment. Fortunately, some wearables will give you a VO2 max approximation, or you can try one of the following tests:
2K Row Test: This is my favorite low impact VO2 max test. Find a rower, set it to 2,000 meters (normally there is a setting that might say 2K or something like that). Start rowing and try to finish in the fastest time possible. Plug your numbers into this calculator here.
12 Minute Cooper Test: This basic test has been used for years. It approximates your VO2 max by measuring how much distance you can run in 12 minutes. Dust off the running shoes and give this a shot. Plug your distance in this calculator to find your VO2 estimate here.
The Different Types of Cardio Training
For the simplicity of this article, I’ve created two major buckets of cardio training. Of course, there are way more, but this is a good start.
Zone 2 Cardio (Low-Intensity Steady-State [LISS])
- What It Is: Sustained, low-intensity effort where you can still hold a conversation.
- Why It Matters: Builds aerobic endurance and heart health without excessive stress.
- How to Do It: Brisk walking, cycling, or an easy-paced run.
High-Intensity Interval Training (HIIT)
- What It Is: Short bursts of intense effort followed by rest.
- Why It Matters: Time-efficient, boosts fitness, metabolism, and fat loss.
- How to Do It: Use a treadmill, bike, rower, or any cardio equipment and pick your interval ratio below. Shoot for 15–20 minutes.
- Beginner: A 1:2 work to rest interval ratio, so the rest is double the work period. For example, you go hard for 30 seconds, then rest for 1 minute.
- Intermediate: A 1:1 ratio. I like to do 30 seconds on/off here, but if you need to shorten the duration, go for it.
- Advanced: The Norwegian 4×4. This is not for the faint of heart—and that’s exactly why AGEIST founder David Stewart loves this one the most. Four minutes of high intensity work, 3 minutes of rest. Repeat for four rounds.
How to Pull It Off In Your Busy Life: Keep It Simple
Aim for 150–180 minutes of cardio per week, mixing in different types to keep things interesting. Here’s a simple weekly structure:
- 2–4 days of Zone 2
- 1–2 days of HIIT
So, this could be as simple as the following:
- Monday / Wednesday / Friday: 30 mins of Zone 2
- Thursday / Friday: 20 mins of HIIT
- Daily walks: 20 mins
That’s 60 mins of Zone 2, 40 mins of HIIT, and 140 mins of walking per week. So the total “cardio” training would be well over 200 minutes, but almost half is coming from walking, which leads to the first question you might have…
Does walking count as my cardio training?
It depends. If you are out of shape, walking could get you into Zone 2, but for most people, a light walk won’t get you there. So here’s what to do: Add some incline or put on a backpack with some weight and that might be enough to get you into Zone 2. And, of course, there are benefits to moving your body and walking; so, if you can only get out for a 15 minute walk and it’s not zone 2, don’t worry too much. You’re still getting benefits.
Do my strength training sessions count as cardio?
Sort of. This is a more complicated question that depends on your fitness level and what type of strength training you’re doing. The short answer is that it can help your cardio system, but it’s not the same as doing Zone 2 training. And if you’re doing more metabolic strength conditioning circuits (stuff like CrossFit or multiple exercises done back to back without much rest), you will get some of the similar benefits of a HIIT style interval workout.
In fact, for many of my busy clients who have limited time, I will give them strength circuits, which will hit on both strength and cardio. While it doesn’t optimize either one, it checks both boxes, and unless you’re a highly trained athlete, this works really well if you only have a short time window for training.
Does the sauna count as Zone 2?
You might notice that your heart rate is elevated in the Zone 2 range when in a sauna, but that doesn’t count toward Zone 2. Getting a sauna is great for a variety of reasons, but you’re not training your cardiovascular system because there’s no muscle activation. The elevated HR is from your nervous system trying to cool you down and therefore not the same as running or biking.
Can I just play my favorite activity/sports as my cardio training?
This one depends on the sport. Tennis, basketball, soccer, biking, running—of course. Golf, curling, throwing darts…probably not. Personally, as a tennis player and surfer, I rely on these activities for the bulk of my cardio training, but I also supplement with a little Zone 2 and some HIIT throughout the week.
What to Do Next?
So now you have the knowledge and a simple plan of action to put it into practice. If you’re just getting started on your fitness journey, remember that every little bit counts—and the most important part is just getting started. For the more experienced exercisers, hopefully this gives you a little more structure to your training plan.
If you want a full assessment of your cardio situation and a free custom plan of action, go ahead and schedule a free strategy session here with me.
Nick Holt is a personal trainer and health coach based out of Tamarindo, Costa Rica.
Surfing transformed his body after a debilitating back injury and got him in the best shape of his life in his 40s. He has created a unique system of training that uses the principles of surfing, functional mobility, and strength training to help people over 40 get leaner, stronger, and move pain-free. Visit his site or reach out to him at nick@nickholtfitness.com.
