What is fit.test?

Hear from the developer

Screenshots of the software in action


fit.test – what does it do?

Steve Selig, PhD, AES, AEP, ESSA Fellow

Purpose: fit.test is a web app for exercise professionals that provides a low cost, low tech platform
for simple and reliable estimations of aerobic fitness that then link beautifully to the creation of
individualised aerobic exercise sessions based on the client’s own data. I wrote fit.test for my own
practice in clinical exercise physiology and then others wanted it. fit.test transforms the way that
exercise professionals provide services for their clients in the critical area of aerobic fitness.

Why did I conceive fit.test?

  •  “If you don’t test your clients’ aerobic fitness, then how can you design an exercise plan for your
    clients that provides for accuracy, safety, comfort and benefit?”
  •  “I knew what I wanted the software to do, but couldn’t find anything like it on the market”
  •  “So I wrote fit.test for my own practice and then others wanted it”

Features of fit.test

1. You may need to change the way you go about some of the services that you provide for your
clients. That is, to use fit.test you will need to introduce exercise testing if you don’t already
provide that service. This typically requires 15-30 minutes of 1:1 with a client but this service can
usually be billed as part of a premium service.

2. fit.test estimates VO2peak or its close cousin VO2max a by using ACSM algorithms as published by
the American College of Sports Medicine1. fit.test also calculates peak or maximal workload.
Here are the reasons why I chose the ACSM algorithms over other algorithms:

  • a. ACSM is the most prestigious exercise and sports science organisation in the world and
    has stood by its algorithms for 2 decades
  • b. unlike most other algorithms, the ACSM algorithms enable estimations of both
    submaximal and maximal VO2 levels; submaximal estimations permit the calculation of
    unique ‘signature’ lines of best fit for heart rate to workload (HR-WL) for each individual
    and this is a feature of fit.test
  • c. ACSM algorithms can be used for most of the prescribed exercise test protocols,
    whereas many of the prescribed tests depend on a particular test procedure and
    algorithm, and lack flexibility which can be inappropriate for a particular client
  • d. There is no need for an exercise test to proceed up to maximal or near maximal
    intensities to use ACSM algorithms and fit.test; submaximal tests work just as well
  • e. ACSM algorithms can be used for customising your exercise test protocols for individual
    clients and this is a feature of fit.test; this is easy to do and fit.test will show you how to
    do this; there are very few algorithms that permit customising of your test protocols
  • f. ACSM algorithms are suited for use for multi-stage exercise tests (MSET), and MSET are
    superior to single-stage exercise tests (MSET); fit.test is designed to be used for MSET,
    not SSET. Some but not all other algorithms use SSET approaches.
  • g. ACSM algorithms can be used for multiple modes of exercise and enable assessments for
    one mode and exercise programming for another mode, although I prefer to test and program using the same mode; it is so easy to test using more than one mode, and then
    program for these modes, and so it is not necessary to test in one mode and then
    program for another mode; however fit.test has the flexibility to allow this
  • h. ACSM algorithms do not depend on measurements or predictions of HRpeak or HRs during
    recovery from exercise; both HR approaches carry significant errors, especially recovery
  • i. By definition no algorithm is perfectly accurate (algorithms ‘estimate’ but don’t
    ‘measure’) and there is no data that suggests that the ACSM algorithms are any better or
    worse than other published algorithms; the average precision of algorithms for VO2peak is
    approx. +/- 10%.
  • j. Most of the fit.test platform (e.g. peak exercise intensity; exercise session plans) does
    not depend on the accuracy of the ACSM algorithms because exercise intensities are
    determined by the unique ‘signature’ line of best fit for HR-WL for each individual

3. Apart from the ACSM algorithms, there are no other predictions, look up tables or assumptions

4. Simple, direct and precise connectivity between individualised exercise testing and
individualised exercise programming

5. Perfect for pre and post testing to precisely measure changes to fitness over time; importantly
this includes data for inclusion in reports to referrers, case managers, insurers and like

6. Good estimations of energy expenditure for different modes and intensities of exercise: this
feature relies on the actual data of the client and not on ‘look up tables’

7. There are 4 modes of exercise testing and training available: WALK, RUN, CYCLE and STEP

8. Multiple methods for prescribing exercise, all based on the client’s own test data (see tables

9. Very simple to use: just measure workload (WL) and HR, and then it takes 1 min to enter test
data, 1 min to prescribe exercise and 1 min to report to your client and/or colleagues; note that
fit.test does not have direct data input from smart watches, apps or devices, but data (especially
HR) from these devices can quickly and easily be inputted into fit.test entry; there is no need for
paperwork, and data can be entered while the client is exercising

10. Exercise testing is so easy as to fit into a normal training session

11. You can customise your exercise test protocols or you can use prescribed protocols

12. You can control the important measure of HRpeak; you are not locked in to using age-predicted
HRpeak as is the case for most other apps: this is another important feature of fit.test that
improves precision for both exercise testing and programming. But you can certainly use agepredicted HRpeak if you want to, and for many clients, this is entirely appropriate
13. fit.test does not fall for some of the traps of other exercise testing protocols; for instance,fit.test does not rely on ‘look up tables’ for HRs, especially age-predicted HRpeak, and instead
relies on the actual HRs of the client; in addition it does not use recovery heart rates that some
protocols use which are invalid for many individuals

14. A unique ‘signature’ line of best fit for HR-WL is calculated and used by fit.test. A feature of
fit.test is this ‘signature’ HR-WL equation which is based on the client’s actual data and does not
use any assumptions or look-up tables. This is a strength of fit.test right through the whole app
(i.e. testing and programming) and is not available in most other apps of its kind

15. fit.test will precisely calculate exercise intensities for programming and this is perfect for interval
training, including high intensity interval training (HIIT); fit.test calculates exercise intensities for
training that even exceed 100% of VO2peak and will return accurate % of these using any of the
methods for exercise programming (see below)

16. Client data is archived and easily accessible: this means you can easily use any of a client’s
previous test results to program exercise and it is also easy to graphically display test results
over time to gauge progress of a client

Here is the flow of the platform

Part 1. Estimations of aerobic fitness (VO2peak or VO2max)

1. Each client undergoes a multi-stage exercise test (MSET) using any of 4 modes of exercise:
WALK, RUN, CYCLE or STEP. fit.test is not intended to be used for single stage exercise tests
(SSET) such as the 6 minute walk test (6MWT). I have written another article on the advantages
of MSET over SSET. Typically, a test lasts 6-12 minutes and has a built-in warmup, saving time.

2. You can use a prescribed MSET such as the Bruce, Modified Bruce, Balke and Naughton protocols on a treadmill, or cycle ergometer tests such as the YMCA submaximal protocol.
Alternatively you can customise your own MSET that is matched to the exercise capacity of your
client. I have written another article in this series on how to easy it is customise your MSET.

3. Most prescribed protocols will dictate the duration of stages (e.g. 1, 2 or 3 minutes). Customised
protocols can be for any duration (e.g. 1, 2 or 3 minutes) for each stage of the MSET.

4. Heart rate (HR) and workload (WL; e.g. watts on a cycle ergometer or speed and gradient on a
treadmill) are recorded for each stage of the MSET. HR is measured at the end of each stage (e.g.
55 or 60 sec into a 1 minute stage) so that HR is representative of that WL. HR and WL can easily
be entered whilst the client is undergoing the test. There is no need for paperwork and the
estimation of VO2peak is available immediately after the test finishes!

5. A unique ‘signature’ line of best fit for HR-WL is calculated by fit.test, and this is used to
calculate WLpeak.

6. VO2 for each WL is estimated by fit.test using ACSM algorithms as published by the American
College of Sports Medicine.

1 This then enables fit.test to calculate an individualised VO2-HR
equation for the full range of exercise intensity used in the test.
7. HRpeak is entered using any of the following four options (this provides for greater precision,
reliability and flexibility than other apps):
a. Age-predicted HRpeak based on Tanaka et al. (2001): HRpeak = 208 – 0.7 x age for healthy
adults2 …. or
b. Actual HRpeak reached during the exercise test in the case that the client reached fatigue
or higher exercise intensity …. or
c. Actual HRpeak measured by the client during other fatiguing or maximal exercise …. or
d. Actual HRpeak measured during a medically supervised exercise stress test
8. VO2peak is estimated by extrapolating the unique VO2-HR equation up to HRpeak. WLpeak is
estimated by extrapolating the unique WL-HR equation up to HRpeak.

9. The test is now finished and can be saved or edited.

10. The exercise professional can now do any of the following:
a. Generate a pdf report of the test for the client or other exercise or health professional.
This report can generate income for the exercise professional and the fee charged is up
to you.
b. Compare this test to another test or tests for the same client and the same mode of
exercise (e.g. CYCLE tests for client ‘John’).
c. Proceed to programming the client for exercise, based on this test result. This can be
either for the same mode of exercise (e.g. CYCLE test to CYCLE program) or to another
mode of exercise (e.g. CYCLE test to RUN program).

Part 2. Exercise program that is directly linked to either this exercise test or another saved test

1. A feature and strength of fit.test is the direct and easy linkages between exercise tests and
exercise session plans that are customised to the needs of the client. You can be sure that
your client is exercising at intensities that are appropriate to his/her exercise capacity and
goals. You can also get good estimations of energy expenditure (volume of exercise) that do
not rely on ‘look up tables’.

2. Each program is an individual session plan and it is simple to generate as many as you like
from an aerobic fitness (VO2peak) test.

3. There are many options for exercise programming for any test. When testing and
programming in the SAME MODE (e.g. WALK), there are five main methods available for

  • Workload (WL)
  • Heart rate (HR)
  • VO2peak
  • VO2 Range
  • HR Range: a resting HR must be entered for this option

4. When testing in one mode (e.g. STEP) and programming in ANOTHER MODE (e.g. WALK),
there are three modes available for programming:
a. Workrate (WR)
b. %VO2peak
c. %VO2 Range

However a word of caution: try where possible to test in the same mode of exercise as
you intend your client to use for training. For example, test and train in RUN, or test and
train in CYCLE. Switching modes from testing to training is permitted on fit.test, but the
precision is not as good as testing and training using the same mode of exercise. Of
course, you can use more than one mode of exercise for training, but then it is advisable
to test for those modes and it is simple to do this.

5. Select the test that you are going to link to your program (i.e. mode and date).

6. Select the method of programming that you wish to use (see above and table below).

7. Enter the required data and any optional data that you wish to enter.

8. The training session will now be displayed both as a table and a graph.

9. Save the program (i.e. session plan) and generate a pdf report. There is a short report option
for your clients and a longer form for you or other health or exercise professionals. As for
testing, the session plan can generate income for the exercise professional and the fee
charged is up to you.


10. Repeat these steps for other session plans.

11. Alternatively to you programming your client’s exercise session, your client can exercise at
intensities of their own choosing and then you can enter this data into fit.test aligned to a
particular test and the %WLpeak and/or %VO2peak will be estimated.
fit.test – what does it do?


1. Alman RE, Sloniger MA. Cardiorespiratory and Health-Related Physical Fitness Assessments.
American College of Sports Medicine’s Resource Manual for Guidelines for Exercise Testing
and Prescription. 7 ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins;
2. Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll
Cardiol. 2001;37(1):153-156.