Muscle metabolism and performance improvement after two training programmes of sprint running differing in rest interval duration

Abstract

Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval.

FNDC5 and irisin in humans: I. Predictors of circulating concentrations in serum and plasma and II. mRNA expression and circulating concentrations in response to weight loss and exercise

“…To assess the effect of exercise, we analyzed circulating irisin levels, before and after 2 or 3 sets of double sprints at first week and after 8 weeks of training, as described in the methods. As previously reported [15], analysis of muscle metabolite contents at week 1 showed that ATP levels were acutely decreased in response to exercise, along with decreased phospho-creatine levels (57.8±3.4 vs 31.8±3.5, mean±SE, p <0.01), and increased creatine, glucose, glucose-6-phosphate, glycerol-3-phosphate, fructose-6-phosphate (0.9±0.3 vs 1.9±0.3, p =0.02), and lactate (Fig. 6).…”

“…Fifteen young, moderately trained, healthy males (age 20.5±1.5 years, BMI 21.9±1.6 kg/m 2 ) were assigned to an 8-week long training program involving 3 training sessions per week, as previously described [15]. Briefly, the training included 2 or 3 sets of runs on an indoor track with two 80-m sprint runs in each set.…”

Altering the rest interval during high‐intensity interval training does not affect muscle or performance adaptations

“…In the present study, we have assessed this hypothesis by employing two different training regimes, matched for total work, but which were associated with different changes in muscle lactate, PCr and hydrogen ion concentration. We show that reducing the length of the between‐interval recovery period, thereby producing a greater decrease in PCr content during each training session (Spencer et al 2006; Saraslanidis et al 2011), did not affect post‐training improvements in muscle PCr resynthesis postexercise. Thus, contrary to our hypothesis, training sessions that were accompanied by greater decreases in muscle PCr content did not result in significantly greater improvements in PCr resynthesis.…”

Irisin and exercise training in humans – Results from a randomized controlled training trial

“…This investigation was originally designed to compare two repeated-sprint protocols [24]. The two training groups were apparently pooled for the retrospective analysis of circulating irisin.…”