SHORT REST INTERVALS ARE BETTER FOR TRAINING SPRINTERS
Bogdanis, G. C., Saraslanidis, P., Petridou, A., Galanis, N., Tsalis, G., Kellis, S., Kapetanos, A. G., & Mougios, V. (2009). Muscle metabolism and performance improvement after two training programs of sprint running. A paper presented at the 14th Annual Congress of the European College of Sport Science, Oslo, Norway, June 24-27.
This study examined the effects of two sprint training programs differing in rest interval duration on muscle metabolism and performance. Young, moderately trained, males (N = 14) were randomly assigned to two groups (N = 7 in each group) and trained three times per week for eight weeks. Each training session included two sets (during the first four weeks) or three sets (during the remaining four weeks) of two 80-m sprints for both groups. Sets were separated by 20 minutes of passive recovery. The rest interval between the two sprints was either 10 seconds (short-rest) or 60 seconds (long-rest). Pre- and post-training field tests included maximal sprints of 100, 200, and 300 m to assess changes in performance. Muscle biopsies were obtained from the vastus lateralis muscle after warm-up and after the first set of two 80-m sprints during the first and last training session. Muscle biopsies were snap frozen and later freeze-dried, homogenized, and analyzed by enzymic spectrophotometric assays for adenosine triphosphate, adenosine diphosphate, creatine phosphate, creatine, glucose, glucose 1-phosphate, glucose 6-phosphate, fructose 6-phosphate, glycerol 3-phosphate, pyruvate, and lactate.
Both training programs improved sprint performance, but the improvement was significantly greater in the short-rest group compared to the long-rest group at the final 100 m of the 200 m run and at the final 100 m of the 300 m run. Changes in muscle metabolites after the two 80 m sprints were not affected by training, except for a reduction in the drop of adenosine triphosphate. The drop in creatine phosphate, the increases in glucose 6-phosphate and fructose 6-phosphate, as well as the calculated anaerobic carbohydrate breakdown were greater in the short-rest group compared to the long-rest group.
Implication. In moderately trained athletes, training with repeated sprints is more effective when performed with a very short rest interval (e.g., 10 seconds) compared to a longer rest interval (e.g., 60 seconds). Performance improvement comes in the latter part of sprint runs.