Does anyone know when and for how long bodybuilders should
undertake gentle long aerobic exercise eg running in order to
keep the heart and lungs fit and healthy? A few years ago one
used to hear of young body builders dying of heart attacks with
the heart all swollen like a geriatric's (admittedly this was
prob due to steroid abuse). I'm trying to bulk out with muscle
and taking lots of fat-free weight gain; but dont want the heart
to be strained. Can u direct me to any journal articles?
Thickening of left ventricle chamber
is actually a normal adaptation for individuals who lift weights,
however, it is not indicative of health issues as it is with
morbid obesity or congestive
heart failure. Interestingly, the heart of aerobically trained
athlete adapts by growing larger, thereby, increasing stroke
volume. In contrast, the heart of weight trained athlete grows
thicker. Basically, when the muscles are under a load during
a lift, the heart has to force blood through the vasculature
that becomes temporarily occluded from the surrounding contracted
muscles This added resistance causes the heart to adapt through
hypertrophy, just how other muscles would adapt under load. Also
see The Pump.
Let's look at the aerobic
prescription guidelines for optimal health, fat loss, and
cardiovascular fitness. You can see intensity required for health
is not as great as is required for cardiovascular fitness. Also
note that aerobic prescription for fat loss is largely dependent
upon calories expended when performing traditional cardio programs.
Also note that sprint training with long active recovery between
bouts can greatly augment fat loss.
Traditional aerobics can tax glycogen
stores which are a necessary fuel substrate for intense weight
training and other anaerobic activities. However, glycogen stores
are typically chronically low anyway during the dieting
phase bodybuilders employ months before a competition to
reduce body fat. In any event, low glycogen stores can decrease
intensity and the time to exhaustion for both weight training
Males who are not accustom to traditional aerobics, can experience
levels at least until their body adapts and their cardiovascular
fitness improves. This is because submaximal exercise at lower
intensities (i.e. 63% maximum oxygen consumption) stimulates
response than higher intensities (i.e. 86% maximum oxygen consumption)
(Farrell, 1983; Naveri, 1985). Significant elevations in cortisol
seem to reduce endogenous testosterone by acting directly upon
the testis to impair the biosynthesis of testosterone (Di Pasquale,
1992, C). This may not be that big of deal for an endurance athlete
who can perform a weight training program to retard muscle loss.
Bodybuilders on the other hand may have more reason to be concerned,
particularly if they are natural bodybuilders and find it difficult
to maintain muscle mass when they are dieting down. In contrast,
women will not experience depressed testosterone levels during
traditional aerobic exercise. In fact, they may see slightly
elevated levels since they produce their testosterone in the
in an area adjacent where cortisol also produced in both men
For these reasons, male bodybuilders
may opt for low intensity aerobics training (such as very brisk
walking) for long durations (2+ hours) most days of the week
(5-6 day/wk) which can be performed instead of traditional aerobics
(Jogging for 20-40 minutes, 3-4 days/wk).
Anaerobic exercise such as weight training, sprints, or High Intensity Interval Training
(HIIT) can burn nine times fat per calorie expended than
can aerobic training alone (Trembblay 1994). Before HIIT is performed,
a general conditioning period of several weeks is typically suggested
to acclimate the body before higher intensities are introduced.
recovery of approximately 4 minutes is suggested allowing
Creative Phosphate stores to be replenished, so maximal or near
maximal intensities can be achieved during each bout.
I do not currently know of any studies comparing the time
of day of exercise to actual weight loss or fat loss. Although
one study reported the time of exercise does not appear to influence
subsequent caloric intake (O'Donoghue 2010). Also, exercising
before or after breakfast also does not seem to influence subsequent
calorie intake (Maraki 2005, Deighton 2012). However, perceived
exertion may be greater for morning exercise as compared to evening
exercise (Maraki 2005).
I would suggest the best time of day to perform your cardio
exercise will come down to the time you find it most convenient,
the time you're more likely to consistently put in the time.
With HIIT as with weight training, a time of day you are feeling
you're strongest would be ideal.
Keep in mind that fat loss will primarily be achieved through
diet with a subtle calorie deficit, just enough to elicit fat
loss but not so great to waste muscle and decrease energy required
for intense weight training.
To monitor your progress, so appropriate adjustments can be made
to both your exercise and dietary regimen, find someone to take
periodic skin fold measurements.
This can be particularly helpful to make sure you are not consuming
too many calories during your bulking up phase, or to ensure
you are not over dieting during your cutting phase. Also see
You can search for further studies on PubMed (external link opens in separate browser
window) also listed on our Journal
Links page (Under Various).
Deighton K, Zahra JC, Stensel DJ (2012). Appetite, energy
intake and resting metabolic responses to 60 min treadmill running
performed in a fasted versus a postprandial state. Appetite;58(3):946-54
Di Pasquale MG (1992). Maximizing lean body mass without
drugs. Drugs in Sports; 1(3):6-12.
Farrell PA, Garthwaite TL, Gustafson AB (1983). Plasma
adrenalcorticotropin and cortisol responses to submaximal and
exhaustive exercises. J Appl Physiol Respirat Environ. Exercise
Naveri H (1985). Blood hormone and metabolite levels during
graded cycle ergometer exercise. Scand J Clin Lad Invest;45:599-603.
Maraki M, Tsofliou F, Pitsiladis YP, Malkova D, Mutrie
N, Higgins S (2005). Acute effects of a single exercise class
on appetite, energy intake and mood. Is there a time of day effect?
O'Donoghue K JM, Fournier PA, Guelfi KJ (2010). Lack of
effect of exercise time of day on acute energy intake in healthy
men. Int J Sport Nutr Exerc Metab; 20(4):350-6.
Trembblay A, Simoneau JA, Bouchard C. (1994). Impact of
Exercise Intensity on Body Fatness and Skeletal Muscle Metabolism,
Metabolism; 43(7): 814-818.