46
Reduced Training Maintains Performance in Distance Runners J. A. Houmard, D. L. Costill, J. B. Mitchell, S. H. Park, R. C. Hickner, andJ. N. Roemmich Human Performance Laboratory, Ball State University Muncie, IN 47306
J. A. Houmard, D. L. Costill, J. B. Mitchell, S.
H. Park, R. C. Hickner, and J. N. Roemmich, Reduced Training Maintains Performance in Distance Runners. mt j Sports Med, Vol 11, No 1, pp 46—52, 1990.
Accepted after revision: June 18, 1989
This investigation examined endurance runners during a 3-week reduction in training volume and frequency. Ten well-conditioned runners were monitored for 4 weeks while training at their normal weekly training
distance (mean SE) (81
5 km/week, 6 days/week).
This period was designated as baseline training (BY). Sixty km/week were run at 75 % VO2max, and the remainder (21 km/week) at 95% VO2max in the form of intervals and
races. The runners then reduced weekly training volume (RT) by 70% of BT to 24 2 km/week and frequency by 17% to 5 days/week for 3 weeks. During RT 17 km/week was performed at — 75% VO2max and the remainder (7 km/week)at 95 %VOmax (intervals and races). The runners were tested weekly and performed 5-km races on a 200-
m indoor track during BT and after 2 and 3 weeks of RT. Maximal heart rate (HR) increased (P < 0.05) by 4 beats/mm at RT week 3, which may have been associated with a decrease in estimated plasma volume (P < 0.01) of 5.62 0.43%. Time to exhaustion during the VO2max tests increased (P < 0.05) by 9.5% at RT week 3. No significant (P> 0.05) changes occurred with RT in body weight, % body fat, overall 5 km race times, VO2max, muscular power (vertical leap and Margaria power test), and citrate synthase activity (at 2 weeks of RT). No alterations in venous lactate, energy expenditure, and HR were observed during submaximal running at two speeds (— 65% and 85% VO2max) with RT. It was concluded that reduced training maintained many endurance training adaptations and racing performance in these well-trained runners for3 weeks. Key words
Endurance running, performance, reduced training
Many endurance athletes and coaches fear a loss in physical conditioning and performance if they reduce training for more than a few days. Hickson et al. (11) examined initially untrained subjects during 10 weeks of training and after 15 weeks of a 75 % reduction in training volume. They observed decrements in long-term endurance with reduced training. This finding (11) may not accurately reflect how shorterterm reductions in training affect performance in chronically endurance-trained athletes. After a 14-day reduction in training volume and frequency, collegiate swimmers improved swimming times by 3 % (4). Unfortunately, there are no data available concerning the impact of similar training reductions on distance running performance. Additionally, performance and endurance-training adaptations (i. e. maximal and submaximal V02, muscle enzyme activities, muscular power) have not been extensively examined during reduced training in well-trained endurance athletes (4, 16), and, to our knowledge, no studies have examined this aspect in distance runners. Therefore, the purposes of this investigation were to (1) examine the effects of a reduced training schedule similar to that used by swimmers upon distance running performance and (2) determine if a reduction in weekly training volume and frequency would maintain training adaptations in chronically endurance-trained runners.
Methods
Experimental Design Ten well-trained male distance runners (age 32.0 2.6 years, weight 62.18 1.97 kg) participated in this study. All subjects signed a letter of informed consent after the risks and benefits of the procedures had been explained. The runners selected were serious, well-trained, and competitive endurance athletes, although not at the elite level. In an effort
to encourage competitiveness during the 5-km races (see below), subjects were selected with relatively homogeneous racing abilities (3.3—3.6 mm/km for 5 km). Subjects had maintained endurance training for at least 2 years.
After initial testing for VO2max, subjects trained for 4 weeks at their normal weekly training distance (Fig. 1). Based upon description of normal training (eg. pace, number, and type of intervals run etc.), we provided each subject with a schedule detailing pace and distance. These 4 weeks
are described as baseline training (BY). Training was monitored by communicating with the subjects several times during mt. J. Sports Med. 11(1990)46—52
GeorgThiemeVerlagStuttgart. NewYork
each week and by examining training logs. During BT subjects
ran 60 km/week, 6 days/week, at their normal training pace (.75 %VO2max, as based upon testing results). The remaining
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Introduction Abstract
ml. .1. Sports Med. 11(1990) 47
Reduced Training Maintains Performance in Distance Runners
*
T*
Testing Procedures
*
60
OTotel distance
60
U Intervals
:.
UL tiLl 12 34 112 3 Trclnlng D1stnce Reduced Trlnlng (weeks)
(weeks)
Fig. I Mean and SE of weekly training distances during four weeks of baseline training and three weeks of reduced training. Interval training was performed at — 95 %VO2max. * 5-km race performed on Saturday of that week.
distance (21 km/week) was run at 95% VO2max in the form of intervals and races. Intervals consisted of a 5—7 km warm-up and 6—10X200—800mat — 95% VOmax, with active recoveries of 400 m. Intervals were performed on Tuesday and Thurs-
day of each week. Five-km races were held on Saturdays (BT weeks 1, 2, and 4) at 0800 hrs, and were included in weekly interval distance. In BT week 3 additional intervals were performed on Saturday since there was no 5-km race (Fig. 1). The BT period did not vary greatly from any of the subjects' normal training routine.
Following completion of BT, subjects reduced training (RI) for 3 weeks. The RT schedule was similar to that used by swimmers in the 10 days prior to competition, in which training volume and frequency were reduced by 63 % and 20%, respectively (4). During RT weekly training volume was reduced by 70% of BT to 24 2km/week, and frequency was decreased by 17% to 5 days/week (Fig. 1). The subjects ran 17 km/week (2—5 km/day on non-interval days) at normal pace (— 75 %VOmax), with the remainder (7 km/week) at — 95% VO2max (intervals and races). The percentage of total weekly distance performed as intervals was approximately the same during RT (29%) and BT (26%). Intervals consisted of a 2—3 kmwarm-up( 75 %VOmax), and 1-2 X 200—800-m runs at — 95 %Omax, with active recoveries of 200—400 m or rest. Intervals were performed on the same days as BT (see above). Five-km races were performed on RT weeks 2 and 3 (Fig. 1). Additional intervals were added on the Saturday of RT week 1. Running during submaximal and maximal testing (see below)
was included in BT and RT as a normal training day (— 4 km/week). The pre-race warm-up (2—41cm, — 75% VOmax) was also included in weekly distance.
To insure adherance to RT, subjects understood that monetary reward for participation would be witheld if there was any deviation from the schedule. Additionally, these competitive runners knew there was the possibility of a substantial improvement in racing performance with RT. The subjects were reminded to maintain RT during testing and by telephone calls. The runners were also required to periodically report to the laboratory before and after training.
The subjects performed a battery of tests at the same time each week. Subjects reported on a Wednesday or Thursday between 0600—0900 hrs after an overnight fast. The tests are presented in the order they were performed during each session. Plasma volume, Margaria power, and vertical leap After 20 mm of seated rest a blood sample was drawn from an antecubital vein. The sample was analyzed for hemoglobin and hematocrit for the determination of percent changes in plasma volume (PV), assuming a constant red cell mass (8). Subjects then ran for 3 mm as a warm-up, and per-
formed 6 modified Margaria power runs (3). Running time was recorded to the nearest 0.001 sec, with the fastest run used
for data analysis. A vertical leap test was also performed. Values were obtained to the nearest 1.5 cm by observing a videotape of the jump in slow motion. The highest of 3 leaps was used in data analysis. The Margaria and vertical leap tests during RT week 1 were used to primarily aquaint the subjects
with these procedures. Consequently, the results were excluded from statistical analysis. Body weights were recorded weekly, and body fat was estimated using skinfolds (2) on BT wks I and4, and RTwk3. Submaximal running
Subjects performed a weekly submaximal treadmill test. The initial 3 mm consisted of a warm-up at a selfselected pace. Treadmill speed was then increased to a level requiring — 65% of the pre-study VO2max. Subjects ran at this pace for 4 mm. The speed was then increased to elicit — 85% of
the pre-study VO2max. Subjects ran at this speed for 5 mm.
Treadmill speed was kept consistent for each subject throughout the study. The 65% and 85% VO2max workloads were selected in an effort to examine two different submaxi-
mal running intensities. These intensities were also easily maintained during the submaximal testing period and allowed
rapid attainment of steady-state. Steady-state V02 was reached after approximately 3 mm at each stage, which agrees with other observations (1). Expired gases were analyzed continuously for 02 (Applied Electrochemistry S-3A 02 analyzer), C02 (Beckman, LB-2 Medical Gas Analyzer), and total volume (Parkinson/Cowan gas meter), for the determination
of V02, ventilation (YE), and respiratory exchange ratio (RER). Data from the last minute of each submaximal exercise stage were used for analysis. Energy expenditure was calculated from RER and V02 (15). Heart rate (HR) was monitored continuously via telemetry (AMF Quantum), with the last minute of each stage used for analysis. Upon conclusion of the run, a blood sample was immediately taken from an antecubital vein and analyzed for lactate (14) and pH (Instrumentation Labs blood gas analyzer). Maximal exercise
In BT weeks 2 and 4 and RT week 3, 02max was determined. After the blood sample from the submaximal running test had been obtained, the subjects immediately resumed running at the 85% VO2max speed. Grade was then incrementally increased by 3 % at 2 mm intervals, to voluntary
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In!. J. Sports Med. 11(1990)
J.A. Houmard, D. L. Costill, J. B. Mitchell, S. H. Park, R. C. Hickner, andJ. N. Roemmich
Table 1 Changes in muscular power, maximal exercise, and plasma volume with re duced training AT week
BT
Variable Vertical leap (cm)
Power (watts/kg) VO2max (mI/kg/mm) Heart rate max TTE (mm)
40.00 2.00 14.07 0.35
13.34 0.53
1.08
—
—
—
—
—
—
2.00 0.34 1.20
41.00 14.29
60.94 190.8 5.85
+ 0.65 2.8
1.70
—0.42
3
42.00 2.00 13.34 0.37
2.00
41.00
186.5 4.28 5.30 0.28
61.81
—
%PV change
2
1
3.85' 0.43*
—5.62 1.26*
Data are mean SE; BT, baseline training; AT, reduced training; Power, Margaria power test; Heart rate max in beats/mm; TIE, time to exhaustion during maximal testing; PV, plasma volume, N = 10. Significance was set at P