How to increase intensity at any level of fitness or experience
Important Disclaimer
If you have heart, metabolic, or kidney disease or are over 45 years old and have 2 or more risk factors (immediate family member with heart disease before age 55, cigarette smoking, high blood pressure, abnormal cholesterol levels, diabetes, sedentary lifestyle, or obesity), you should consult your physician before starting any type of exercise.
Recommendations: Physical Activity Guidelines for Americans
The US DHHS suggests:
At least moderate intensity aerobic activity for at least 150 minutes per week. Anything that gets your heart pumping faster counts.
Muscle-strengthening exercises at least twice a week on non-consecutive days. Do activities that make your muscles work harder than usual
If that’s more than you can do right now, do what you can. Even 5 minutes of physical activity has real health benefits.
Study: Moderate to Vigorous Intensity (MVPA) Physical Activity Lowers Risk of Death
Researchers tracked 650,000 people for 10 years. They had them report leisure time physical activity minutes. There was a substantial benefit - lower hazard ratio of all-cause mortality (lower risk for death) with increasing amounts of moderate to vigorous physical activity (MVPA).
At the lower end of the MVPA totals, there was a large reduction in mortality risk with small increases in MVPA
Those who were at 150-300 minutes per week of MVPA had a 40% lower risk of death compared to those who were physically inactive.
Here’s another view of greater life expectancy with greater activity levels.
Activity Level (MET-hours/week)
Equivalent To...
Life Expectancy Gain
0.1 – 3.74
Low (Up to 75 min brisk walk/week)
+1.8 Years
7.5 – 14.9
Recommended (150 min/wk brisk walk)
+3.4 Years
22.5+
High (450+ min brisk walk/week)
+4.5 Years
4 in 5 Americans Don’t Meet Physical Activity Guidelines
Slightly more than 20% of men meet physical activity guidelines for aerobic and muscle-strengthening activity. About 15% of women do.
We tend to overestimate our activity! Many studies show this. In one study, 62% of adults thought they met the guidelines…only 9.6% actually did when comparing data from accelerometers (activity monitors) to what they reported.
1 Metabolic Equivalent (1 MET) is the rate you burn energy (calories) at rest (sitting still). The number of METS you are at (the rate of calories you burn) increase with increased intensity of physical activity. This means you burn more calories with higher intensity.
Intensity Category
Metabolic Demand (METS)
Sedentary / Resting
< 1.5 METS
Light Intensity
1.6 – 2.9 METS
Moderate Intensity
3.0 – 5.9 METS
High Intensity
6.0+ METS
Measuring Exercise Intensity - Type of Activity
Some activities are more likely to be high or moderate intensity. Here are examples.
Moderate Intensity
High Intensity
Walk, 2.5–4 mph
Heavy cleaning
Mowing lawn
Cycle, 10-12 mph
Badminton
Tennis doubles
Ballroom dance
Walk >4 mph or hills, jog 6 mph
Shoveling
Cycling fast (>14 mph) or on hills
Basketball, soccer
Tennis singles
Jump rope
Aerobic dancing
Measuring Exercise Intensity - Talk Test
The talk test is a simple method for measuring your exercise intensity.
Intensity Level
The "Talk Test" Rule
Light Intensity
You can talk and sing without puffing at all.
Moderate Intensity
You can talk but not sing.
Vigorous Intensity
You can't say more than a few words without gasping for breath.
Measuring Exercise Intensity - Rate of Perceived Exertion
You can use rate of perceived exertion (RPE) to estimate your exercise intensity.
RPE
Intensity Level
How it Feels
1
Very Light
Anything other than complete rest.
2 - 3
Light
Feels like you can maintain for hours; easy to breathe and carry on a conversation.
4 - 6
Moderate
Feel like you can exercise for long periods of time; able to talk and hold short conversations.
7 - 8
Vigorous
On the verge of becoming uncomfortable; short of breath; can speak a sentence.
9
Moderate intensity is 64 to 76% of maximum heart rate
Vigorous intensity: 77 to 93% of maximum heart rate
Why Exercise Intensity Matters
In addition to the amount of exercise (such as number of steps or minutes), intensity of exercise matters, too. One study among 6213 men, with an average of 6.2 years follow-up, found a lower risk of death with increasing fitness level.
Peak exercise intensity was the single greatest predictor of survival
For each additional MET of fitness (maximal exercise intensity), there was a 12% higher rate of survival. Here’s what a 1 MET increase looks like.
If you can originally...
With a 1 MET Increase, you can...
Cycle at 10 mph
Cycle at 12 mph
Walk at 3.0 mph
Walk at 3.5 mph with the same effort
Run a 12-minute mile
Run a mile in 10.5 minutes
Water plants, dusting
Rake leaves, scrub floors
In another study, moderate-to- vigorous exercise lowered risk of diabetes. This was among 6,000 people. An extra 20-min brisk walk a day was associated with 11% lower odds of type 2 diabetes. In other words, accumulating the same volume through higher intensity activity was associated with lower odds of T2D than accumulating through lower intensity activity
How to Increase Intensity*
* Only if your provider agrees that it is safe to do so
Ways to Increase Intensity
Intervals or HIIT
Speed - walk, pedal, jog, or swim faster
Incline/hills or resistance - increase resistance on the elliptical trainer or stationary bike, hike up hills, add incline to the treadmill
Change activities - you can make your body work harder when it learns a new activity
Whole body exercises - try free weights or body weight exercises instead of weight machines that target one muscle group
Less rest or circuits - try cycling, walking, jumping jacks, or other movements between sets of weights
High-Intensity Interval Training (HIIT) to Increase Exercise Intensity
Alternate periods of “work” (high intensity) with periods of “rest” (lower intensity)
“Rest” is “active recovery” - 30-120 seconds
“Work” is at a higher intensity - 10-60 seconds
“Work” and “rest” can be same or different activities
Add a warm-up and cool-down
Work up to 5-20 minutes total (work plus rest)
Lark Is There for You!
If you have a Fitbit tracker, sync it with your Lark app. Give the Lark app permission to access your Google Fit or Apple Healthkit if you use other devices (like an Apple watch). Respond to the weekly questions from the Lark Coach about moderate-to-vigorous intensity exercise minutes. Enter your workouts manually in the app
Ask support.lark.com if you have questions!
References
U.S. Department of Health and Human Services, Physical Activity Guidelines for Americans, 2nd Edition
Moore SC, Patel AV, Matthews CE, Berrington de Gonzalez A, Park Y, Katki HA, Linet MS, Weiderpass E, Visvanathan K, Helzlsouer KJ, Thun M, Gapstur SM, Hartge P, Lee IM. Leisure time physical activity of moderate to vigorous intensity and mortality: a large pooled cohort analysis. PLoS Med. 2012;9(11):e1001335. doi: 10.1371/journal.pmed.1001335. Epub 2012 Nov 6. PMID: 23139642; PMCID: PMC3491006.
Quinlan C, Rattray B, Pryor D, Northey JM, Anstey KJ, Butterworth P, Cherbuin N. The accuracy of self-reported physical activity questionnaires varies with sex and body mass index. PLoS One. 2021 Aug 11;16(8):e0256008. doi: 10.1371/journal.pone.0256008. PMID: 34379676; PMCID: PMC8357091.
Source: American College of Sports Medicine Exercise Testing and Prescription
Jonathan Myers, Ph.D., Manish Prakash, M.D., Victor Froelicher, M.D., Dat Do, M.D., Sara Partington, B.Sc., and J. Edwin Atwood, M.D. Exercise Capacity and Mortality among Men Referred for Exercise Testing
Strain, T., Dempsey, P. C., Brage, S., Wareham, N., et al. Quantifying the Relationship Between Physical Activity Energy Expenditure and Incident Type 2 Diabetes: A Prospective Cohort Study of Device-Measured Activity in 90,096 Adults. Diabetes Care, 46(6), 1145–1155. (2023)
