simply be that combining heavy strength training with HIGH intensity aerobic training is the
problem.
In direct contrast to the data presented above, when endurance athletes (cyclists and
runners) perform heavy resistance training, endurance performance improves (82,83). This
further supports that the studies above were simply measuring overtraining rather than true
interference effects of strength and aerobic training.
No one has examined the effects of combining weight training with low intensity aerobic
training only. Anecdotally, many individuals find that a small amount of aerobic training,
perhaps 20 minutes, two to three times per week at a low intensity (heart rate at least 15
beats/minute below lactate threshold) may aid in recovery by improving blood flow and general
conditioning (23). As well, individuals trying to gain weight find that a small amount of aerobics
can stimulate hunger.
Individuals wishing to maximize performance in the weight room are discouraged from
performing extensive amounts of aerobic training, especially at high intensities (77). However,
small amounts of aerobic training should not be detrimental, and may even aid in recovery and
overall performance.
Gender Differences
Under a microscope, there is no physiological difference between women’s muscle and
men’s. By the same token, men and women’s muscle respond similarly to training. When placed
on the same training program, women respond as well if not better than men do (84-86). Women
can gain muscle in the same fashion as male trainees do, just not to the same levels typically
seen in males (12,19).
The largest difference between male and female trainees is in the ultimate level of
muscular development which can occur. The majority of this difference in trainability is due to
differences in testosterone levels. Women have lower levels of testosterone at rest (65,86) and do
not show the same increase from training as men (1,69).
There is preliminary data that women should be trained differently during the different
phases of the menstrual cycle. However, this requires more research (87). For the time being,
there is no evidence that men and women should follow different training programs (84).
Detraining
For various reasons, athletes frequently have to take time away from training and a
discussion of detraining is necessary. The deadaptations from stopping weight workouts are
essentially the opposite of the initial adaptations. Recall that the initial adaptations to strength
training are neural with adaptations in the muscle occurring later. Detraining occurs in the
reverse order. Maximal strength begins to drop within a week but muscle size does not begin to
decrease for at least 2 weeks (18,88) reflecting a decrease in the neural aspects of strength
(13,18).