Lactic acid accumulation in cardiac patients performing circuit weight training: implications for exercise prescription.
OBJECTIVE
Because blood lactic acid (LA) levels may be important in prescribing exercise for cardiac patients, this study documented the LA response to four different circuit weight training (CWT) protocols and compared these responses to both maximal treadmill and LA threshold values.


METHODS
Intervention study following a crossover trial design.


METHODS
A phase III community-based setting.


METHODS
All subjects had documented cardiac disease and were volunteers.


METHODS
We used 40% and 60% of the one-repetition maximum (1-RM) for six exercises and 30 or 60sec of rest between each station, resulting in four protocols, performed in random order. A discontinuous treadmill test was conducted, and the LA threshold was determined.


METHODS
The main dependent variable was LA after each CWT protocol.


RESULTS
No signs or symptoms suggestive of cardiovascular distress during any of the four CWT protocols were reported. A repeated-measures analysis of variance showed that the LA threshold value was significantly less than all four CWT protocols (p < .05). The CWT responses were also compared with the traditional LA threshold value of 4.0mmol/L, and both 60% protocols were significantly elevated (p < .05).


CONCLUSIONS
Because no positive signs or symptoms were reported, we recommend starting stable cardiac patients on a CWT program with an initial load between 40% and 60% 1-RM and allowing at least 60sec of rest between exercises.
Department of Kinesiology, University of New Hampshire, Durham 03824, USA.
D W
DW
DeGroot
T J
TJ
Quinn
R
R
Kertzer
N B
NB
Vroman
W B
WB
Olney
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000534:rehabilitation*; D001026:Coronary Artery Bypass / Q000534:rehabilitation*; D017147:Defibrillators, Implantable; D005081:Exercise Therapy; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D017770:Lifting; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000534:rehabilitation*; D014891:Weight Lifting / Q000502:physiology*
D019344:Lactic Acid