Web App – Explained
Calculate Pressure | LOP | Aerobic Fitness | One Repetition Maximum
Calculate Pressure (mmHg) ⬇
This Module can calculate the recommended restriction pressure (mmHg) as an alternative to setting the pressure relative to Limb Occlusion Pressure (LOP). Relevant for effective, safe & convenient BFR pressure
Limb Occlusion Pressure (% LOP) ⬇
As an alternative to the Calculate Pressure Module, this feature enables You to calculate the pressure (mmHg) as a percentage of Limb Occlusion Pressure assessed by the Bluetooth Device. Relevant for effective, safe & precise BFR pressure
Bike Tests (Aerobic Fitness) ⬇
Submaximal and all-out Bike Tests to estimate VO2 max Fitness Level and Watt max, then use the slider to set the desired intensity. Relevant for BFR aerobic exercise
One Rep Max (% of 1RM) ⬇
Estimate your 1RM to calculate repetitions and load, then use the slider to set the desired intensity. Relevant for BFR resistance Training
- Calculate Pressure (mmHg) Module Explained ⇩
- Aerobic Fitness (Bike Tests) Module Explained ⇩
- One Repetition Maximum (1RM) Module Explained ⇩
- Limb Occlusion Pressure (LOP) Module Explained ⇩
When direct assessment of Limb Occlusion Pressure (LOP) aka Arterial Occlusion Pressure (AOP) is not accessible or You just find it inconvenient, it is recommended to use the “Calculate Pressure” module.
Before using the Calculate Pressure module, remember to measure the circumference of your thigh or upper arm in a relaxed resting state.
Please, consider the output of the app is neither connected to the LOP module and the pressure is directly applicable for BFR Training, so no need to calculate a percentage of this output.
As displayed in the video above the individual characteristics of the user enables the calibrated algorithm to estimate a recommended pressure (mmHg) for BFR Training. Based on these data the app instantly calculates a direct applicable pressure for the user. Please mind, the app has been calibrated with Fit Cuffs® Product selection and may not be appropriate to be used with other BFR products.
LOP and AOP are the terms that mean the lowest pressure required to completely cease the arterial blood flow into the extremity distal to the cuff. For further explanation of LOP and AOP and information on how to operate the LOP Device check fitcuffs.com/lop.
Nerd Alert – How & Why the Module Works
The aim of the Module is to predict AOP, then subsequently calculate the sweet spot of 40-70% and 50-80% LOP for the upper and lower body, respectively. Currently, the algorithm seems to predict this recommended pressure for +95% of all people.
The module has been developed from the comprehensive research and data in the prediction of LOP and to a less degree from practical experience with BFR in various populations. So, this module utilize the relevant determinants of LOP to estimate AOP in order to provide the user with a recommended pressure (mmHg) well suited for BFR training.
When operating this module, different characteristics are needed for the algorithm to calculate an indicative-individual pressure. Specified as limb circumference and Systolic blood pressure which is the most important factors. Though, age, gender, body compositions, training condition, and recent experience with BFR Training has also been included.
It is not commonly advised to use arbitrary pressures just by guessing or use the same pressure for all individuals. That is because absolute pressures restrict blood flow differently dependent on the individuals anthropometrics.
Thus, our internal and external data conducted on Fit Cuffs and cuffs of similar width shows that, 80 mmHg and 100 mmHg for the upper and lower body, respectively, would be applicable for most individuals (Chulvi-Medrano et al. 2023). But due to inter-individual anthropometrics, especially limb circumference, subcutaneous fat, and arterial blood pressure, absolute pressures does not restrict blood flow homogeneously.
From the comprehensive research and data, it seems that limb circumference can explain about 50-70% of the inter-individual variability of LOP/AOP when the same cuffs are being applied. Though thigh circumference is the biggest anthropometric predictor of LOP, it seems that other factors are also of importance. The body of evidence shows that both gender, age, and body composition influence LOP/AOP and the relative amount of blood flow that is restricted at sub-LOP pressures.
That is why these predictors are included in the algorithm, along with “training condition”, as we find this of particular importance for the Ratings of Perceived Exertion (RPE) during BFR Training. But please consider the width of the cuff is the most important predictor of LOP/AOP. So, please mind that the “Calculate Pressure” module is developed for and by the use with Fit Cuffs® product selection.
Disclaimer: Many of the algorithms developed for the prediction of AOP includes brachial systolic blood pressure, but for the matter of convenience this has been omitted in the app.
Even though there is a discrepancy between the width of the Leg Cuffs V2.1 (10 cm) and the contoured Leg Cuffs V3.1 (11 cm) our internal testing seems not to be of any clinical relevance for the estimation of a recommended pressure.
“In addition, we have outlined models which indicate that restrictive cuff pressures should be largely based on thigh circumference and not on pressures previously used in the literature.” – (Loenneke et al. 2012).
“Tourniquet inflation pressure setting based on AOP estimation method provides a bloodless surgical field that is comparable to that of LOP determination method with lower pneumatic inflation pressure and less required time for cuff pressure adjustment ..” – (Tuncali et al. 2018)
“If researchers and practitioners can measure arterial occlusion pressure, we suggest using a wider cuff (e.g., 12 cm wide cuff) to ensure arterial flow can be occluded in the lower body.”
Bland Altman Plot of the actual arterial occlusion compared to the estimated arterial occlusion pressure (12 cm wide cuff). Differences between actual and estimated is on the y-axis. On the x-axis is the average of the two values. The proportional bias is noted by the solid black line and the 95% confidence interval is noted by the gray shadow around the line. The mean bias and the 95% limits of agreement are noted by the dotted lines. Individual values are noted by black dots.
FIGURE 2 – Yamada et al. (2022) Potential considerations with estimating blood flow restriction pressure in the lower body using a narrower cuff
Limb occlusion pressure (LOP) versus the ratio of tourniquet cuff width to limb circumference. For any given limb circumference, the tourniquet pressure required to stop arterial blood flow decreases inversely as the width of the tourniquet cuff increases.
Original source:
Graham et al. (1990) Occlusion of arterial flow in the extremities at subsystolic pressures through the use of wide tourniquet cuffs
While increasing from 10 to 20% rAOP or 80-90% (rAOP) both significantly impacted blood flow, changing cuff pressure between 30 and 80% rAOP did not significantly impact SFA blood flow (30 vs. 80% rAOP: P=0.08; 40-70 vs. 80% rAOP: P=1.00). Thus, while blood flow may be trending towards a difference between 30% and 80% rAOP, the data convincingly illustrates that cuff pressures ranging from 40-80% rAOP elicit very similar blood flow responses at rest.
rAOP = resting Arterial Occlusion Pressure
- Grenshaw et al. (1988) Wide tourniquet cuffs more effective at lower inflation pressures
- Tuncali et al. (2006) – A New Method for Estimating Arterial Occlusion Pressure in Optimizing Pneumatic Tourniquet Inflation Pressure
- Tuncali et al. (2016) Clinical utilization of arterial occlusion pressure estimation method in lower limb
- Tuncali et al. (2018) Tourniquet pressure settings based on limb occlusion pressure determination or. arterial occlusion pressure estimation in total knee arthroplasty? A prospective, randomized, double blind trial
- Loenneke et al. (2012) Effects of cuff width on arterial occlusion: Implications for blood flow restricted exercise
- Loenneke et al. (2015) Blood flow restriction in the upper and lower limbs is predicted by limb circumference and systolic blood pressure
- Crossley et al. (2019) Effect of Cuff Pressure on Blood Flow during Blood Flow–restricted Rest and Exercise
- Noordinn et al. (2009) Surgical Tourniquets in Orthopaedics
- Jessee et al. (2016) The Influence of Cuff Width, Sex, and Race on Arterial Occlusion Implications for Blood Flow Restriction Research.
- Mouser (2017) A tale of three cuffs the hemodynamics of blood flow restriction.
- Cirilo-Sousa et al. (2019) Predictive Equation for Blood flow restriction Training
- Schmidt (2021) (Thesis) Validity and reliability of an oscillatory blood pressure measurement device to determine the arterial occlusion pressure in healthy adults for blood flow restriction training exercise protocols: a cross-sectional study.
- El-Zein (2020) (Thesis) the use of a portable Bluetooth Device to measure blood flow restriction training pressure requirements: a validation study
- Yamada et al. (2022) Potential considerations with estimating blood flow restriction pressure in the lower body using a narrower cuff
- Chulvi-Medrano et al. (2023) Blood Flow Restriction Training in Clinical Rehabilitation: Occlusion Pressure Methods Relative to the Limb Occlusion Pressure
Via the Bike Tests, you can assess VO2 Max, Fitness Level, and Watt Max, which are commonly known as “indirect tests” of VO2 Max. The tests can be performed on any type of exercise bike, but remember the Bike Tests are always performed without BFR. Subsequently, you can use the built-in slider to set the intensity For BFR exercise relative to Watts or Beats Per Minute (BPM) i.e. Heart Rate Reserve (HRR). The module consists of 4(3) different tests built into the same interface:
1. To get started, You only need to enter Age, then the app will estimate your Max Pulse and Resting Pulse. This basic data enables You to set the intensity relative to Heart Rate Reserve (HRR) via the slider. For a more precise i.e. valid estimation of Your HRR, you can input Your Max Pulse and/or Resting Pulse.
2. The Golden standard for “indirect tests” Aerobic Fitness is the Watt Max Bike Test. This is applied through an “all-out” progressive protocol, as you must reach the point of your maximum sustainable watts as absolute failure in order to get a valid test result. So, this test should probably not be used in at-risk populations, i.e. heart or respiratory conditions without approval from a physician. As a rule of thumb, if you’re not used to strenuous aerobic exercise, this should probably not be conducted without gradual exposure to near-maximal intensity aerobic exercise.
3. The Submaximal “One-point-test”, that can be used to estimate your VO2 Max, Fitness Level, and Watt Max. To use this feature, you need to find your “steady-state-pulse” at a corresponding Watt Load, i.e. Load 1 and Pulse 1. Like the previous tests, you can add your Resting Pulse and Max Pulse to obtain a better estimation of your actual Aerobic Fitness.
4. For a better approximation of your Aerobic Fitness, you can use the so-called Submaximal “Two-point-Test”. The protocol is similar to the One-point-test, just applying an additional step-wise increment test and pasting the corresponding data into the app, Load 2 and Pulse 2.
First picture above: The intensity set at 60% relative to Heart Rate Reserve (HRR) as shown in Work Pulse by Beats Per Minute (BPM)
Second picture above: The test results after the Watt Max Bike Test, subsequently set at 70% intensity
Third picture above: The results from a Submaximal Bike Test specified as “One-Point-Test at 50% intensity
Fourth picture: The results from a Submaximal Bike Test specified as “Two-Point-Test” at 40% intensity
This module can be relevant for anyone into aerobic fitness and performance training, or for clinicians working in cardio and or respiratory rehab with or without BFR. The Bike Tests can be used to estimate Aerobic Fitness, because of the near-linear relationship between Watts and Working Pulse and secondly the strong correlation between VO2 Max and Watt Max, commonly known as “indirect tests” VO2 Max tests. The algorithm used in the app has a very high ability to detect any relevant change in Aerobic Fitness.
Check our Blood Flow Restriction Blog (July 09, 2020), for further explanation of the different tests, with reference to relevant research papers and other sources.
The One Rep Max module can be used to calculate weight (kg), reps and a percentage of One Repetition Maximum (% 1RM) for resistance training with or without the application of BFR, which can be relevant to track progress or general exercise programming.
By using the 1RM module you can simply estimate your 1RM with a submaximal load for a specific exercise, or just enter your known 1RM, then use the slider to set the relative load.
As a rule of thumb, for safe and effective BFR augmented resistance training, you should aim for 20-40% of 1RM calculated for each exercise individually. For low-pressure BFR Training, i.e. 40-60% Limb Occlusion Pressure (LOP), we recommend utilizing “low-load” as about 25-40% of 1RM. For higher relative pressure BFR training i.e. 60-80% LOP, we recommend using “very low-load” i.e. 15-25% of 1RM.
Please also mind, that just like the bike tests, RM testing should always be conducted after a proper and exercise-specific warm-up without BFR.
In many cases, it may not be appropriate to measure 1RM, e.g. after surgery, injury, etc. For such circumstances, we recommend that you test the contralateral limb (uninjured limb) and use this measurement to calculate 1RM. Subsequently, use this proxi-measurement to set the load for the injured body part.
Example 1: Rehab after knee surgery. Test and calculate the maximum strength (1RM) of the unaffected leg in a specific exercise. Use this data in the app, to find an indicative load (kg) for the rehab exercise.
In this case, please mind the associated strength loss in the affected limb. So, relative to the time and severity of the surgery, aim for about 20% 1 RM with the recommended 30x15x15x15 rep protocol. For longtime adaptations, remember to progress either reps, pressure (mmHg) or load for each exercise accordingly.
Example 2: General fitness applications with BFR. We recommend using less pressure (40-60% LOP) and loads about 25-40% 1RM. It is commonly not feasible, in regard to training adherence, going to absolute failure. That is also why we recommend using a preset load and rep-scheme, then progress either load, reps, or pressure (mmHg) for the succeeding training sessions.
Testing your 1RM requires a high degree of caution to avoid injury. We recommend finding the maximum weight (Load/kg) you can manage with a proper form for 5-10 Repetitions (Reps) after an appropriate and exercise-specific warm-up.
Subsequently, you can use the sliders to set “% of 1RM”, “Reps” or “kg” relative to a percentage of your estimated 1RM.
Because of a significant intratester and intertester variance to different exercises and between individuals, respectively, this calculation is only an estimation of 1RM.
Remember to include about 60-75% of your bodyweight when applicable, e.g. back squat, split squat etc.
Example: Your current back squat is 100kg with a body weight of 80kg, use 100kg + 60kg = 160kg.
Epleys formula is currently used for the 1RM module: 1RM = Load * (1 + Reps / 30)
Source: Epley, B. Poundage chart. In: Boyd Epley Workout. Lincoln, NE: Body Enterprises, 2985. p. 86
One repetition maximum can be used as an upper limit, in order to determine the desired load for an exercise (as a percentage of the 1RM). Source: en.wikipedia.org
The LOP Module simply helps you calculate a % of the measured Limb Occlusion Pressure (LOP).
This Module functions independently of the Calculate Pressure Module. And please mind you need the 3. party app to operate the original Bluetooth Device as this web app does not operate any of the LOP Devices. For information concerning the dedicated app for the LOP Devices check the email sent from info@fitcufs.com containing the tracking number of your order. For more information please also see: fitcuffs.com/lop
