How hard, how long, and how often you exercise are crucial. The 'overload principle' suggests that you need to challenge yourself by going a little harder or further to get a positive response. That's because if you do the same sort of exercise at the same intensity all the time, you will see minimal positive change in your body (though you will enjoy the health benefits of exercise).

For example, if you're used to doing a comfortable 5km run a few times a week, challenge yourself by running further - which increases your exercise volume, or running faster, which increases your exercise intensity and heart rate.

For example, try a sprint interval session, which would be something like running as fast as you can from one lamp pole to the next, then alternating walking and sprinting between lampposts. Or run up a hill, walk down it, and repeat. These kinds of sessions will eventually improve your VO₂ max and running pace, and also lower your heart rate over your more comfortable runs.

The most powerful factor in increasing your fitness is exercise intensity, or how hard exercise feels to you. Studies, including the ACSM's 12th edition, highlight that HIIT is more effective in improving cardio fitness than endurance training, especially in healthy, young to middle-aged adults.

You're working towards a fitter you, and that's terrific! Here are some tips to help you move from a less active lifestyle to building a solid foundation for good cardio fitness.

• Start with simple exercises: Begin with easy cardio exercises like walking, cycling, or swimming.
• Find your pace: If your VO₂ max score is below 35ml/kg/min, aim for an intensity that brings your heart rate to 70% of your maximum (220 - your age).
• Take it slow: Gradually increase exercise duration. This builds a strong foundation, reduces injury risk, and makes exercise a lasting habit.
• Baby steps: Stick to low to moderate intensity for the first six weeks. Add five to ten minutes to your sessions every few weeks before trying higher intensity.
• Be patient: Don't stress about slow progress. You're on the right track. As you get fitter, focus on making your workouts more challenging.
• Stay active: Fit movement into your day; take breaks, climb stairs, stretch, or dance. Get creative with adding physical activity to your routine. Aim to do at least 5,000 steps every day.

Consider your weight: If you're carrying extra weight, consistent exercise, along with a healthy balanced diet can help you lose some, and it will also make exercise easier. It may be worthwhile signing up to the Vitality Healthy Weight programme for on-demand support from a qualified dietitian, healthy eating plans and more.

Well done on achieving a good fitness level! To reach the next level, try these tips to elevate your cardio fitness.

• Mix it up: Engage in different exercises (like strength or resistance training, endurance training, or interval training) to experience various heart rate zones.
• Keep a balance: Combine short HIIT sessions with longer moderate-intensity exercises for a well-rounded routine.
• Adjust your intensity: If your VO₂ max reading is below 35ml/kg/min, aim for 70% of your max heart rate. If it's between 35 and 49ml/kg/min, go for 77% to 95% of your max heart rate.
• Stay active: Fit more movement into your day; take breaks, climb stairs, stretch, or dance. Get creative with adding physical activity to your routine and reducing your sedentary time.

Consider your weight: If you're carrying extra weight, consistent exercise, along with a healthy balanced diet can help you lose some, and it will also make exercise easier. It may be worthwhile signing up to the Vitality Healthy Weight programme for on-demand support from a qualified dietitian, healthy eating plans and more.

You're in top shape! Now it's time to push your limits and improve your performance even further. Boost your cardio fitness with these advanced strategies:

• Up the intensity: If your VO₂ max reading is between 35 and 49ml/kg/min, aim for 77% to 95% of your max heart rate. If your VO₂ max score is above 49ml/kg/min, aim for 90% of your heart rate or more.
• Try progressive overload: This more advanced technique entails gradually increasing your exercise volume over time for consistent improvement.
• Consider periodisation: This entails following a structured training plan with build-up and recovery periods to enhance your performance and minimise your risk of injury and overtraining.

Challenge yourself, keep going, and enjoy the rewards of maintaining a super-fit lifestyle!

Endurance training, also known as continuous cardio training, involves exercising at a comfortable to moderate intensity for an extended period. It goes by various names like base training, long-slow distance training, moderate training, high-volume low-intensity training, and steady state.

• Aerobic exercise: It's all about exercising 'with oxygen.' Your heart pumps oxygenated blood to your muscles, allowing them to burn fat and carbohydrates for fuel. This enables you to sustain exercise for longer periods compared to anaerobic exercise. (Anaerobic exercise involves short, fast, high-intensity exercises that don't make your body use oxygen like it does for cardio.)
• Duration matters: The time you can exercise depends on your fitness level. Aim for at least 150 minutes a week, gradually increasing to 300 minutes as you get fitter. This equates to a goal of 30 to 60 minutes of exercise, 5 or more days a week.
• Exercise choices: Options include fast walking, comfortable running (indoors or outdoors), or using cardio machines. Maintain a heart rate between 60% and 85% of your maximum heart rate.
• Slow and steady: Gradually increase exercise duration over the first six weeks, starting with low to moderate intensity. As you get fitter, you'll see that you are able to train harder at a lower heart rate.

Interval training involves alternating shorter, intense bursts of exercise with slower, recovery periods throughout the session. It's applicable to various exercises, from cardio to resistance and bodyweight exercises.
Interval training can be applied to walking, running, cycling, resistance exercises, bodyweight exercises, and more.

Example sets:

• Cardio: Warm up for 10 minutes, followed by four sets of four minutes hard effort, and three to four minutes recovery. For example, walk up a hill fast and recover as you walk back down.
• Resistance: Warm up for 10 minutes, then do five rounds of non-stop exercises with a moderate or heavy weight, with a rest period of a few minutes between every round. Find examples of strength and resistance training sessions on the Vitality Home-workout channel here.

HIIT, or high-intensity interval training, involves short bursts of intense exercise followed by recovery periods. The intensity pushes your body into an anaerobic state, making fuel without oxygen, also known as 'maximal cardio training' state.

Intensity levels: The intensity can vary, with recovery ratios ranging from 1:1 to 1:3. For example, with a 1:1 work to rest ratio, for each 1 minute of training, you rest for 1 minute. Or, with a 1:3 work to rest ratio, for each 1 minute of high-effort interval training, you recover at low effort for 3 minutes. You can play around with the duration and ratios, depending on the intensity you're exercising at. This is to allow your heart rate to fully recover to under 70% of your maximum heart rate after each round. The more intense the interval, the longer the recovery time you need.

Recovery is key: Remember to also allow enough recovery time between workout days for your body to adapt and improve cardio fitness. You can do an active recovery workout (a lighter workout at a lower intensity, like core or strength training) This will minimise your risk of injury and overtraining.

Beginner friendly: Beginners can start with brisk or incline walking intervals at lower heart rate percentages and shorter durations.

Build your strength: To prevent injuries when incorporating high-intensity training, include strength training weekly. If time is limited, combine strength training with moderate-intensity cardio or add a 10-minute HIIT session to the end of your strength workout. Do cardio last to maintain good form during strength training.

Example set: Try four rounds of exercises such as a 500m row or sprint, followed by dumbbell squat presses, box jumps, or skipping, and a one-minute rest. Adjust the sets based on your fitness level.

We're all unique, and so is our cardio fitness potential! The fact is, the highest cardio fitness level you can reach is affected by several factors, including your age and sex (which is why Vitality takes these into account when allocating your Fitness Level from your VO₂ max score), your genetics, your past and present fitness level, your health status (including body composition) and the type of exercise we do.

But don't be discouraged - studies show that you don't need to be a pro athlete to enjoy the health benefits of good cardio fitness. Here are some points to keep you motivated:

• If you're starting with low cardio fitness, you have the most to gain health-wise by aiming for an improvement to good fitness. Incorporating short bouts of low- to moderate-intensity exercise during the week can lead to noticeable improvements. This not only enhances fitness but also brings numerous health benefits, reducing the risk of chronic illnesses and promoting overall well-being.
• As you become fitter and stronger over time, challenging yourself even more during exercise brings additional health and fitness gains. For those with good to superior cardio fitness levels (levels 3 to 5), improvements reinforce existing health benefits and elevate them further.
• Understand that your fitness journey is unique, and patience is the key to seeing results. Consistency in your efforts will pay off over time.
• Recognise that everyone's progress is different, and improvements in cardio fitness come at varying rates. Your fitness journey is your own, and comparing it to others may not accurately reflect your progress. What matters is the commitment to your fitness journey and the positive changes you're making for your health.
• Physical results take time. Be patient with yourself and your body. Consistent effort, combined with a positive mindset, will lead to the changes you're working towards. Remember, you're still getting all the mental health benefits of exercise, which are immediate and significant. These are not dependent on looking or even feeling fitter - so none of your effort is being wasted, health-wise.

Whether you're just starting or already on the path, focus on your personal goals and celebrate each win. Even small improvements in your VO₂ max score can hugely reduce your risk of death or developing a chronic disease, so don't lose sight of the great progress you're making towards a healthier you!

Calculating your heart rate involves determining your beats per minute (bpm), typically measured in the number of heartbeats in one minute. Wear a heart rate monitor, which can be a chest strap or a wrist device and follow the instructions for your specific monitor to get an accurate reading.

Once you know your heart rate, you can determine your heart rate zones. These zones help tailor your exercise intensity to achieve specific fitness goals.

• Resting Heart Rate (RHR): Your heart rate when you are at rest, typically measured when you wake up in the morning. The normal RHR range for most adults is 60 to 100 bpm. A lower RHR often indicates better cardiovascular fitness, so by tracking your resting heart rate over time, you will see your RHR drop as you get fitter.
• Maximum Heart Rate (MHR): The highest number of beats per minute your heart can achieve during intense exercise. An estimate can be found by subtracting your age from 220.
• Target Heart Rate Zones: These are percentages of your maximum heart rate and are often used to guide exercise intensity.

For example: If your estimated MHR is 180 (220 - age of 40) and you want to exercise in the moderate intensity range (70 - 80% of MHR), you'd aim for a heart rate between 126 - 142 BPM (180 * 0.7 to 180 * 0.79).

Remember, individual factors such as fitness level, medications, and health conditions can affect your heart rate. If you have concerns or specific health conditions, it's best to consult with your doctor before you start a new exercise plan.