Four factors can be manipulated to achieve better training effects.

1. Frequency (how often a person exercises)

3 to 5 days/week is recommended by the American College of Sports Medicine (ACSM) for those who want to develop and maintain cardiorespiratory fitness and make favourable changes in body composition.

2. Intensity (how strenuously a person exercises)

Target Heart Rate (THR) for estimating intensity for aerobic exercise:

THR = Intensity (%) x Maximum Heart Rate (HRmax),

where HRmax = 220 - Age

** Recommended training intensity for aerobic fitness is 60% - 90%.**

e.g. The target training heart rates for a 20-year-old are:
At 60%: THR = 60% x HRmax = 0.6 x (220-20) = 120 bpm
At 90%, substitute 0.9 for 0.6 in the above calculation, = 180 bpm.

Therefore the target training heart rate for the 20-year-old should fall between 120 - 180 bpm.

• As for resistance training,

  i. Repetition Maximum (RM) - the maximum load that a muscle or muscle group can lift in a given number of repetitions before fatiguing. e.g. 80% of 1RM
  ii. Rest between sets -- the longer the break, the lower the exercise intensity; contrarily, the shorter the break, the heavier the exercise load.

3. Time/Duration (how long each training session is)

20 minutes or more continuous aerobic activity; in addition, some form of resistance training to maintain muscle fitness.

4. Type/Mode

Depending on personal preferences, choose one or more types of activities to create an active life style. No matter what type of physical exercise you do, do it regular to obtain long-term training effects.