>80% of NSmen are actually physically UNFIT for reservist military training/war...

(<20 actually="" fitness="" manage="" nsmen="" pass="" physical="" test="" to="">50% NSmen so terribly disabled/ infirm, they are excused from taking physical fitness test in SAF of any kind (no modified fitness options available (swimming, cycling etc) either)).

Operationally-ready national servicemen (NSmen) running as part of IPPT Preparatory Training (IPT) programme in Maju Camp on Sept 8, 2014. -- ST PHOTO: ONG WEE JIN - 

Calculation:
'300,000-plus operationally ready national servicemen (NSmen) who form the backbone of the SAF': [SAF bends and stretches over IPPT: My Paper; 01Jul2014]

'...Individual Physical Proficiency Test (IPPT)... ...The 2010 figures from the Ministry of Defence - the most recent available - showed that half of the 116,000 NSmen who take the test annually fail it.' [Tougher penalties for NSmen who skip IPPT; ST 31Oct2014]

% of all NSmen who are able to achieve minimum pass @ IPPT =
[(116,000/2) / 300,000+] = <<19 .33333="" span="">
Or much less than 20% considering that denominator is in excess of 300,000 personnel.

% of all 'operationally ready' NSmen who are actually medically fit to take IPPT=
116,000 / 300,000 = <38 .666="" span="">
Less than 40% NSmen are physically (medically) fit enough to qualify for IPPT testing to have their fitness recorded and computed annually.