Why cardiovascular fitness matters just as much as strength — and how testing can help you train more effectively.
Strength training is one of the most valuable things you can do for your long-term health.
Building muscle, improving strength and maintaining physical capacity as we age can have a profound impact on our quality of life.
But there’s another important piece of the puzzle that often gets overlooked.
Cardiovascular fitness.
You can be incredibly strong, carry plenty of muscle and still have relatively poor cardiovascular fitness.
And if our goal is to remain healthy, capable and independent for as long as possible, we need to pay attention to both.
At NG Health & Fitness in Weybridge, we’ve recently introduced cardiovascular fitness testing to help us better understand how our clients respond to exercise and how we can improve their fitness more effectively.
Because having the muscle is one thing.
You need the engine to go with it.
What is cardiovascular fitness, and why does it matter?
Cardiovascular fitness describes how effectively your heart, lungs, blood vessels and working muscles support sustained physical activity.
When you exercise, your muscles require energy. To produce that energy aerobically, your body needs to deliver oxygen to the working muscles and utilise it effectively.
This involves several interconnected processes:
- Your lungs bringing oxygen into the body.
- Your heart pumping oxygenated blood around the body.
- Your blood vessels delivering that blood to the working muscles.
- Your muscles extracting and utilising oxygen to produce energy.
Improving cardiovascular fitness can increase your ability to perform physical activity, recover between bouts of exercise and tolerate greater workloads.
Importantly, higher levels of cardiorespiratory fitness are strongly associated with a reduced risk of cardiovascular disease and premature death.
Which brings us to one of the most widely discussed measurements of cardiovascular fitness.
What is VO₂ max?
VO₂ max represents the maximum rate at which your body can take up and utilise oxygen during intense exercise.
It’s commonly expressed in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min).
Generally speaking, a higher VO₂ max indicates a greater capacity to perform sustained aerobic exercise.
However, VO₂ max isn’t determined by your heart and lungs alone.
It’s influenced by several factors, including:
- Cardiac output: How much blood your heart can pump per minute.
- Oxygen transport: How effectively oxygen is carried through your bloodstream.
- Muscular oxygen extraction: How much oxygen your working muscles can extract from the blood.
- Mitochondrial capacity: The ability of your muscles to utilise oxygen for aerobic energy production.
These systems work together, and improvements in cardiovascular fitness can involve adaptations across several of them.
VO₂ max is a useful measurement, but it isn’t the only indicator of cardiovascular performance or health.
Two individuals with similar VO₂ max values may have very different abilities to sustain exercise at a given intensity.
That’s where additional information, such as ventilatory thresholds, becomes particularly useful.
Why your smartwatch heart rate zones might be wrong
Many fitness watches and exercise machines estimate your maximum heart rate using a population-based formula.
One of the most familiar is:
220 − your age = estimated maximum heart rate.
For a 50-year-old, that would produce an estimated maximum heart rate of 170 beats per minute.
But there’s a problem.
This formula is based on population-level observations and cannot accurately predict every individual’s maximum heart rate.
Some people have a maximum heart rate substantially higher than their age-predicted value. Others may have a considerably lower one.
Age is only one factor, and individual variation can be significant.
More importantly, even knowing your actual maximum heart rate doesn’t automatically tell us where your most useful training zones lie.
Two people with identical maximum heart rates may reach important physiological thresholds at very different exercise intensities.
This is why prescribing cardiovascular training purely as a percentage of estimated maximum heart rate has limitations.
Your heart rate zones should ideally reflect how your body actually responds to exercise, rather than simply how old you are.
What are ventilatory thresholds?
One of the particularly useful aspects of cardiovascular exercise testing is the ability to estimate ventilatory thresholds.
These are points during progressively harder exercise where your breathing response changes in relation to the increasing workload.
Two commonly identified thresholds are VT1 and VT2.
VT1: The first ventilatory threshold
VT1 generally represents the point where breathing begins to increase disproportionately relative to oxygen consumption.
Below this threshold, exercise is typically relatively comfortable and sustainable.
You can usually maintain a conversation, and the effort can be continued for a prolonged period.
This is often associated with lower-intensity aerobic training, although VT1 and the boundaries of commonly used Zone 2 models are not always identical.
Training at these intensities can help improve aerobic endurance and support adaptations that make sustained exercise more efficient.
VT2: The second ventilatory threshold
VT2 occurs at a higher exercise intensity, where ventilation increases more sharply as the body responds to the metabolic demands of harder exercise.
At this point, breathing becomes considerably more demanding, conversation becomes difficult and the exercise intensity is much harder to sustain.
VT2 is useful when considering higher-intensity cardiovascular training and an individual’s ability to tolerate demanding workloads.
Why do these thresholds matter?
Imagine two people exercising at 140 beats per minute.
For one person, that might represent a relatively comfortable aerobic workload.
For the other, it could be an intensity approaching their second ventilatory threshold.
Same heart rate.
Very different physiological demands.
Identifying these thresholds can help us prescribe exercise more appropriately, rather than assuming that the same heart rate or percentage of maximum heart rate means the same thing for everyone.
It’s worth noting that ventilatory thresholds are estimates derived from physiological responses, and their accuracy depends on the testing method, protocol and quality of the data collected.
Can strength training improve VO₂ max?
Interestingly, yes.
Resistance training can improve cardiorespiratory fitness in certain populations, particularly individuals who are previously untrained or deconditioned.
Someone returning to exercise following a period of inactivity may experience improvements in both strength and aerobic fitness from a well-designed resistance training programme.
However, these improvements aren’t necessarily equivalent to those achieved through dedicated cardiovascular training.
As an individual becomes stronger and better conditioned, resistance training alone may provide insufficient stimulus for continued improvements in aerobic capacity.
This doesn’t diminish the importance of strength training.
Muscle mass, muscular strength and cardiovascular fitness all contribute to physical function and long-term health.
The mistake is treating them as interchangeable.
Being strong doesn’t automatically mean you’re aerobically fit. And being aerobically fit doesn’t automatically mean you’re strong.
A comprehensive approach to exercise should consider both.
Do you need to spend hours doing Zone 2 cardio?
Not necessarily.
Lower-intensity aerobic exercise can be an excellent way to improve cardiovascular fitness.
Walking, cycling, swimming and other forms of sustained activity can all contribute to better health and fitness.
For many people, this type of training is also accessible and relatively easy to perform independently.
At NG Health & Fitness, we generally prioritise the parts of exercise programming where our specialist input can make the greatest difference during paid personal training sessions.
That might include strength training, movement assessment, exercise modification or more structured cardiovascular intervals.
For appropriate clients, interval training can be an effective and time-efficient way to target particular aspects of cardiovascular fitness.
However, higher intensity isn’t automatically better.
The appropriate training intensity depends on the individual’s health, current fitness, goals and ability to tolerate exercise.
Someone with limited exercise experience may benefit most from gradually building their aerobic base.
Another individual may be ready for more demanding interval-based work.
The aim isn’t to make cardiovascular training as difficult as possible. It’s to make it appropriate for the person doing it.
How cardiovascular fitness testing works at NG Health & Fitness
We’ve introduced the Pro X cardiovascular testing system to provide additional information about how individuals respond to exercise.
For suitable clients, testing may involve a progressive exercise protocol on a stationary bike.
The workload increases in stages while we monitor physiological responses, including heart rate and breathing-related measurements.
Depending on the protocol and quality of the data, this can help us estimate:
- VO₂ max: An indication of maximal aerobic capacity.
- VT1: The first ventilatory threshold.
- VT2: The second ventilatory threshold.
- Individualised training intensities: Heart rate and workload ranges that can help guide exercise prescription.
Importantly, not everyone needs or should undergo a maximal exercise test.
For individuals with certain medical conditions, symptoms or cardiovascular risk factors, maximal testing may be inappropriate without further medical assessment or clearance.
Where suitable, submaximal testing and less demanding assessments may provide useful information.
Our priority is always to select an assessment appropriate to the individual, rather than forcing everyone through the same testing procedure.
Cardiovascular fitness testing is not a substitute for medical diagnosis or a clinical exercise stress test.
What happens after the test?
Collecting data is only the beginning.
The real value comes from understanding what the results mean and using them to guide training decisions.
At NG Health & Fitness, our assessment-led approach considers the individual rather than simply assigning a generic exercise programme.
Cardiovascular testing can help us explore questions such as:
Are you lacking basic aerobic conditioning?
You may benefit from gradually increasing the amount of lower-intensity cardiovascular activity you perform.
Are you already reasonably well conditioned but struggling with harder efforts?
Appropriately prescribed intervals may help develop your ability to tolerate and sustain higher exercise intensities.
Are you returning to exercise after a prolonged period of inactivity?
A more conservative approach may be appropriate, allowing us to build capacity gradually and monitor your response.
We also recognise that a single test cannot tell us everything.
Sleep, fatigue, medication, health status, training history and numerous other factors can influence exercise performance.
Testing provides information that we interpret alongside your goals, health history and response to training.
It gives us a better starting point, not an infallible answer.
Building strength and cardiovascular fitness for longevity
If your goal is to remain healthy, capable and independent for decades, focusing exclusively on either strength or cardiovascular fitness is unnecessarily limiting.
Strength training helps us maintain muscle, produce force and preserve physical capacity.
Cardiovascular training helps develop the systems responsible for supporting sustained physical activity.
Both can contribute to better health outcomes, and both deserve consideration within an individualised exercise programme.
At NG Health & Fitness, our philosophy has always been that exercise should have a purpose.
We assess the individual, identify what we’re trying to improve and select exercises and training methods accordingly.
Our new cardiovascular testing equipment gives us another way to make those decisions more informed.
Because ultimately, time is finite.
And if you’re committing time and effort to exercise, it makes sense to understand what you’re trying to achieve and whether your training is moving you in the right direction.
Cardiovascular fitness testing in Weybridge
NG Health & Fitness is a private personal training studio in Weybridge, Surrey, specialising in individualised strength training, biomechanics assessments and exercise programming.
We’re now introducing cardiovascular fitness testing to help suitable clients better understand their aerobic fitness and identify opportunities for improvement.
Whether you’re already strength training regularly, looking to improve your cardiovascular health or simply interested in understanding your current fitness, we’d be happy to discuss whether testing could be useful for you.
Interested in cardiovascular fitness testing?
Get in touch with NG Health & Fitness to find out more about the assessment process and how we can help you build a more complete approach to your long-term health.
You need the engine as well as the chassis.
Proper coaching. Built around you.
