Measures of Fitness

Fitness is often at the top of the wish list for people thinking about their future. Some 66% of Americans make fitness their number one New Year’s Resolution each year [1]. But what exactly is fitness, and how do you know how far you’ve progressed in achieving it?

If you make exercise a regular habit, your fitness will improve. In this case, fitness involves becoming aware of your increased physical capacity during exercise and ability to recover more quickly from a bout of physical activity. But can your fitness be measured in an objective way outside of the feeling it provides you?

Fitness can be an abstract idea, feeling different for each person and coming in many shapes and sizes. In this post, we’ll discuss some of the simple ways that you can track your relative fitness throughout your exercise escapades, as well as some of the more sophisticated methods that can be used to assess your absolute fitness compared to others.

Sit & Stand With Only Your Feet

The sitting-rising test is surely one of the simplest ways to assess your level of general fitness. In the late 1990’s, Brazilian physician Claudio Gil Araujo developed this quick clinical test as a general assessment of flexibility, balance stability and musculoskeletal fitness [2]. Ultimately, this test has proven to be a significant predictor of all-cause mortality (death by all causes) in adults aged 51-80 [3] and is commonly used in the clinical setting today [4]. The sitting-rising test measures your ability to transition from a standing position to sitting and back again, without using any points of contact with the ground other than your feet. Every additional point of contact is a deduction from a potential perfect score of 10.

For people with a score less than 8, mortality risk doubles over the next 6 years compared to people who score greater than 8. With a score less than 3, this risk increases five times.

Try this quick test now and see if you can score a perfect 10!

Here’s a fun video of other people trying this test. Learn more here.

For me, the key message of this study is that maintaining balance as you age is a crucial skill for longevity. If you’ve tried the sitting-rising test and you’re not happy with the outcome, try some of the following scientifically-backed exercise routines relating to balance, flexibility and strength to help improve your predictive lifespan score on this test.

Core strength training

Core strength training in older individuals improves sitting-rising test performance [5]. Some examples of core strength exercises include abdominal bracing, front bridge pose and side bridge pose.

Yoga

Yoga is proven to improve flexibility, balance and joint mobility, along with other measures of fitness such as body weight, explosive power and cardiovascular endurance [6]. Improving these skills will have a measurable impact on your sitting-rising score.

Power walking

Nordic walking is more effective than normal walking in increasing upper body strength and decreasing blood lipid levels [7]. One study showed that 65+ year old female participants doing three hours of Nordic walking per week for 12 weeks significantly improved their sitting-rising performance over equivalent control group participants.

Track Your Body Composition

When beginning a weight loss journey, measuring your baseline metrics and tracking physical changes in your body over time are great ways to quantify your personal progress. Tracking also provides extra motivation once you start to see improvements. In fact, self-monitoring is one of the strongest predictors of successful weight loss [8]. Deliberate attention towards tracking the outcome of behavioral changes (i.e. weight change in response to increased exercise) is central to reinforcing positive habits.

Beyond weight, there is a more holistic way to track body composition changes that has more relevance to future disease risk… But it is not body mass index (BMI). Waist-to-height ratio has been proven to be a more effective predictor of type 2 diabetes and cardiovascular disease risk than traditional measures of BMI and waist circumference alone [9].

To measure this ratio, you will need a flexible, non-elastic tape measure. Wrap the tape measure around your waist with the bottom edge of the tape aligning with the top of your hipbones. Take 2-3 normal breaths, then note the measurement at the end of the third breath.

Divide the number you get for your waist circumference by your height (in the same units as the waist measurement, for example in inches) to calculate your waist-to-height ratio.

You can see if your result falls into a healthy range with the Ashwell Shape Chart. Your waist circumference should generally be less than half of your height. That means that your waist-to-height ratio should be less than one half or 0.5. If you are 5 feet and 8 inches tall, for example, to be healthy your waist should measure less than 34 inches around.

If your waist circumference is greater than half of your height, take that as motivation to see your physician and/or a weight loss, nutrition or fitness coach!

Progress Tracking

Besides looking at changes in your body, a more direct way of measuring your fitness is tracking exercise-related stats. Whatever your exercise of choice, be it running, swimming, cycling, weightlifting or other, set up a standard route or routine and record your performance each time. Your goal should always be to improve, or at least equal, your previous efforts.

Your progress becomes explicitly visible when you can see the time shaved off a run or the increased weight you can lift from week to week. Once you become accustomed to the initial level of exercise, for example a 5 kilometer run (~3 miles), you can step it up to 10 kilometers (~6.2 miles) and start the process again.

Resting Heart Rate

Getting into more objective measures of fitness that can be compared between people, your resting heart rate (RHR) has been proposed as a quick, low tech and inexpensive indicator of your heart health [10]. If your heart is already working hard when you’re at rest, it has less capacity to increase its work rate when you begin exercise.

By subjecting your body to blood-pumping exercise (aerobic conditioning), your heart grows stronger and your cardiovascular system becomes more efficient at pumping blood around your body. Studies have shown that exercise improves regulation of the heart by the body’s autonomic nervous system, which manifests in a lower RHR and higher longevity [11].

To measure your RHR, sit down and get comfortable for five minutes. Make sure you haven’t had any stimulants such as caffeine recently. Count the number of times your heart beats in a minute. The normal RHR range is 60-100 beats per minute (BPM), but 60-80 BPM is considered optimal [12]. Athletes can have a resting heart rate of 49-55 beats per minute. A resting heart rate of 55-60 for men and 60-65 for women is considered excellent, while heart rates above 75 for men and above 78 for women would be considered below average to poor, warranting a wellness check and a more regular fitness routine.

Sidebar: Know your target heart rate, via American Heart Association

“When the Women’s Health Initiative (WHI) examined data on 129,135 postmenopausal women, they found that those with the highest resting heart rates – more than 76 beats per minute – were 26% more likely to have a heart attack or die from one than those with the lowest resting heart rates – 62 beats per minute or less. If your resting heart rate is consistently above 80 beats per minute, you might want to talk to your doctor about how your heart rate and other personal factors influence your risk for cardiovascular disease.” – Harvard Health

Besides being a marker of physical fitness, RHR is also a predictor of all-cause mortality. A long-term follow-up study of 2,800 healthy middle-aged men, where participants’ resting heart rate was initially measured in 1985-1986 and followed up 16 years later (with 1,082 deaths occurring in this time), found that RHR is a significant risk factor for mortality [13]. Participants with a RHR of greater than 90 had a three times higher risk of premature death than did participants with a RHR of less than 50, and for every 10 point rise is RHR, risk of premature mortality increased by 16%.

However, it must be considered that RHR isn’t the perfect way to compare fitness levels between people, with many factors influencing it such as gender, age and measurement errors relating to your level of hydration, temperature, caffeine intake, emotional state and medication use [12].

Heart Rate Recovery

A test related to resting heart rate that measures the efficiency of your cardiovascular system is your heart rate recovery after intense exercise. The time in which it takes your heart rate to recover after high intensity exercise measures the efficiency of your cardiovascular system.

To calculate this measure of fitness, start exercising and maintain your heart rate zone at 70-80% of your maximum heart rate (220 minus your age) for 10 minutes. (You can use a FitBit or other similar device to make sure you hit and maintain your target heart rate zone.) Stop and note your heart rate at this point, then time your recovery for two minutes. Measure your heart rate after this recovery period and use the difference in these two measurements to assess your level of fitness [14].

If your heart rate recovers by 50 beats or more in two minutes (for example, from 148 beats per minute to 98 beats per minute), you are very fit on this scale of cardiovascular fitness.

Similar to resting heart rate, studies have also found that heart rate recovery is strongly predictive of premature death. In one study, participants within the lowest 20% of heart rate recovery within one minute of exercise (less than 10 beats per minutes recovered) had a roughly 6 fold increase in risk of premature death within the next 6 years, compared to participants in the top 40% for heart rate recovery, with recovery of over 20 beats per minute [15].

Musculoskeletal Fitness

For the experienced exercisers out there, the CrossFit fitness baseline test is a more intensive routine used to benchmark an individual’s fitness [16]. This test involves the following series of activities to be completed in as little time as possible:

• 500 meter row
• 40 bodyweight squats (full depth, hip crease below knee)
• 30 sit-ups (shoulders starting on the ground, sit up and touch your feet)
• 20 pushups (chest to the ground)
• 10 pull-ups (chin above bar, full extension at the bottom)

Other variations of this routine exist. This timed workout assesses strength, muscular endurance and mental toughness during strenuous activity. Once you’re able to complete the workout within the cut-off time (10-11 minutes), the next time range provides a target for continual improvement. A time range below 4 minutes and 30 seconds is considered Pro/Elite.

CrossFit defines fitness on the basis of competency across ten general physical skills: cardiovascular/respiratory endurance, stamina, strength, flexibility, power, coordination, agility, balance and accuracy [17].

Maximum aerobic capacity

One of the most intensive measures of fitness, which requires specialized equipment and is commonly undertaken by high performance athletes, is the maximal exercise test (AKA maximal aerobic capacity). You may have seen participants of this test on a treadmill or stationary bike, with tubes strapped up to a respirator-like device. These tubes are required to measure the oxygen consumption and carbon dioxide production of the participant throughout increasingly intense physical activity levels.

The aim of the test is to assess when the participant has reached their maximum aerobic capacity or volitional fatigue (when the participant no longer performs the activity with perfect form). The average healthy adult has a maximum aerobic capacity or VO_2max within the range of 32–50 mL/(kg·min) [18], whereas the upper limits of aerobic capacity for elite athletes is around 90 mL/(kg·min) [19].

Many methods of calculation are used to determine VO_2max, but the FirstBeat method is most commonly used for commercial applications. For more information, a detailed video on VO_2max can be found on their website.

No Matter the Test – Track Over Time!

A key theme throughout this blog post is the tracking of your fitness progress as you exercise, whether the measure of fitness is as simple as the sitting-rising test and the resting heart rate test, or as intensive as calculating VO_2max.

If this post has motivated you to challenge yourself to improve your fitness, the easiest way to facilitate this fitness tracking is by downloading LifeOmic’s new LIFE Extend app. This platform provides a place to input your fitness data, in addition to data for other areas that impact your health and longevity such as nutrition, sleep and mindfulness.

References

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