Keep Fit

Last edited, 29 April 2020.


The following is with reference to ACSM[1] guidelines. ACSM is considered the gold standard for exercise recommendations.

Q. I run twice a week. Can I say I exercise regularly?

A. The definition for regular exercise: It has to be a planned and structured physical activity, for at least 30 minutes in moderate intensity, at least 3 times a week, for the last three months.

Q. What should be the recommended amount of physical activity for a healthy adult?

There should be more than or equal to 150 mins/week of physical activity, at moderate intensity or, more than or equal to 75mins/week of physical activity at vigorous intensity.

Twice the amount on the recommendation will result in additional health benefits.

Q. How do I access my exercise intensity?

Exercise at the correct intensity can help us get most out of our physical activity. This can ensure that we are not pushing ourselves too hard or too little.

Exercise Intensity is determined by our heart rate response. Exercise intensity can be determined as Low, Moderate or High/Vigorous. Your exercise intensity must generally be at a moderate or vigorous level for maximum benefit.

The followings are some ways that we can determine our exercise intensity level:

  1. The Talk Test
    • During our workout, if we can still sing catching our breath, we are in a low intensity workout level.
      If we are unable to sing but can still carry a conversation, we are in moderate intensity.
      If we can’t talk more than a few words without pausing for a breath, we are in vigorous intensity.
    • The talk test is the most convenient way to determine our exercise intensity level, especially for the seniors.
  2. The RPE Test
    • Borg Rating of Perceived Exertion[2] is widely used as a reliable indicator to monitor our physical activity intensity level. It measures intensity through a defined scale of 6 to 20.
    • For moderate intensity, aim for 12-14 RPE[3]. Above 14 will be vigorous intensity.
How you feel on your exertionBorg rating Examples
(for most adults <65 years old)
none6Reading a book, watching television
very very light7-8Tying shoes
very light9-10Chores like folding clothes that seem to take little effort
fairly light11-12Walking through the grocery store or other activities that require some effort but not enough to speed up your breathing
somewhat hard13-14Brisk walking or other activities that require moderate effort and speed your heart rate and breathing but don’t make you out of breath
hard15-16Bicycling, swimming, or other activities that take vigorous effort and get the heart pounding and make breathing very fast
very hard17-18The highest level of activity you can sustain
very very hard19-20A finishing kick in a race or other burst of activity that you can’t maintain for long
Source: Borg G.A. Psychophysical bases of perceived exertion. Medicine and Science in Sports and Exercise. 1982; 14:377-381.
  1. MET
    • MET, metabolic equivalent of task, is used to qualify the intensity of an activity based on our resting metabolic rate. 1 MET is equivalent to energy expenditure sitting at rest, with oxygen uptake 3.5ml/kg/min.
<3.0 METs
For light intensity
3.0–6.0 METs
For moderate intensity
>6.0 METS
For vigorous intensity
Examples of light intensity activities:

. Walking—slowly
. Sitting—using computer
. Standing—light work (cooking, washing dishes)
. Fishing—sitting
. Playing most instruments
Examples of moderate intensity activities:

. Walking—very brisk (4 mph)
. Cleaning—heavy (washing windows, vacuuming, mopping)
. Mowing lawn (walking power mower)
. Bicycling—light effort (10–12 mph)
. Badminton—recreational
. Tennis—doubles
Examples of vigorous intensity activities:

. Walking/hiking
. Jogging at 6 mph
. Shoveling
. Carrying heavy loads
. Bicycling fast (14–16 mph)
. Basketball game
. Soccer game
. Tennis—singles
The above estimates are based on a healthy adult.

Q. I have a heart rate monitoring device. How do I determine my physical intensity level with it?

A heart rate monitoring device offers a more objective measurement of our physical intensity level. To do this, we need to know our maximum heart rate and resting heart rate. From here, we can calculate our desired target heart rate zone.

  1. To determine your maximum heart rate.

    We can use the formula: 208 – (0.7 x Age).
    • For example, if you are 45 years old, your maximum heart rate will be 208 – (0.7 x 45).
      Your maximum heart rate will be 162bpm.
  2. To know your resting heart rate. Take note of your heart rate reading during rest or when you just wake up.
    • For example, your resting heart rate is 70bpm.
  3. To calculate your desired moderate physical intensity range:
    Formula: 40% to 59% x (Maximum heart rate – Resting heart rate) + Resting heart rate

    To calculate your desired vigorous physical intensity range:
    Formula: 60% to 85% x (Maximum heart rate – Resting heart rate) + Resting heart rate

    Based on the formula and the examples provided for your maximum heart rate and resting heart rate, your
    • moderate physical intensity range will be 107bpm to 124bpm
    • vigorous physical intensity range will be 125bpm to 148bpm

Q. What food can improve sports performance?

Research has shown that foods such as Royal jelly, American ginseng, contribute to the performance of athletes.


1 The American College of Sports Medicine