COSTILL, D. L., R. THOMAS, R. A. ROBERGS, D. PASCOE, C.
LAMBERT, S. BARR, and W. J. FINK. Adaptations to swimming training:
influence of training volume. Med. Sci. Sports Exerc., Vol. 23, No. 3,
pp. 371-377, 1991. In an effort to assess the contributions of a period
of increased training volume on swimming performance, two matched groups
of collegiate male swimmers were studied before and during 25 wk of
training. For the first 4 wk of this study, the two groups trained
together in one session per day for approximately 1.5 h.d-1. During the
following 6 wk (weeks 5-11), one group (LONG) trained two sessions per
day, 1.5 h in the morning and 1.5 h in the afternoon. The other group
(SHORT) continued to train once each day, in the afternoon with the LONG
group. Over the final 14 wk of the study, both groups trained together
in one session per day (1.5 h.d-1). Although the swimmers experienced
significant improvements in swimming power, endurance, and performance
throughout the 25 wk study, there were no differences between the
groups. However, during the 6 wk period of increased training, the LONG
group experienced a decline in sprinting velocity, whereas the SHORT
group showed a significant increase in sprinting performance. The test
results suggest that a 6 wk period of two 1.5 h training sessions per
day does not enhance performance above that experienced with a single
training session of 1.5 h each day. It was also noted that both groups
showed little change in swimming endurance and power after the first 8
wk of training, though their performances improved significantly after
each taper period.
(C)1991The American College of Sports Medicine