Intermittent sprint, plyometric training builds up running stamina

Both intermittent sprint (IST) and plyometric (PT) training regimens improve 10-km running performance and peak power, according to a recent Singapore study.

“The current study was the first to investigate the effects of explosive strength training on 10-km running performance. It was also the first study to look at the effects of IST on endurance running performance,” said researchers, noting that the benefits of such training regimens occurred despite decreases in weekly running mileage.

Fourteen moderately trained male endurance runners were assigned to receive IST (n=7) or PT (n=7). Weekly mileage dropped significantly in both groups (IST: 32.7±15.8 to 28.8±16.1 km; p=0.03; PT: 26.1±8.6 to 20.4±11.3 km; p=0.004). [J Sport Health Sci 2019;8:471-477]

Despite these changes, runners in both groups logged significant improvements in their 10-km running times. Men in the IST group, for instance, who took 53.95±8.60 minutes to finish 10 km before the training, only needed an average of 51.95±7.93 minutes (p=0.03) to cover the same distance after the intermittent sprint regimen.

Men who were assigned to the PT group likewise improved, such that their 10-km times dropped from 50.47±6.75 to 48.35±7.10 minutes (p=0.03).

Both test training regimens also resulted in significant changes in the runners’ muscle power. For instance, those who received the IST saw an increase in their peak power, growing from 3,274±133 W before training to 3,368±136 W after (p=0.002). The same was true for the PT group (3,100±269 to 3,287±247 W; p=0.01).

Similar effects were reported for relative peak power, which increased from 48.1±6.7 to 49.5±6.9 W/kg (p=0.007) in the IST group, and from 48.9±5.8 to 51.7±5.4 W/kg (p=0.01) in the PT group.

Neither IST nor PT had significant effects on other physiological and biomechanical variables, such as peak oxygen uptake, heart rate, blood lactate, contact time, running economy and leg stiffness, among others.

“In summary, these findings showed that 6 weeks of IST and PT did not have any effect on running biomechanics of moderately trained [individuals],” said the researchers. Instead, “the current study showed that there was improvement in peak power during the [countermovement jump] test after the training intervention in both groups.”

“This suggested that the improvement in running performance after a 6-week intervention was most likely due to the improvement in muscular power,” they added.

In the present study, runners were instructed to continue with their usual training regimens while performing IST or PT twice a week. Before each training session, participants completed 15 minutes of warm-up, including vertical jumps, high-knee exercises, jogging, side shuffles, lunges and squats.

Those in the PT group were asked to jump to the maximum height for each repetition, while those assigned to IST were instructed to sprint at maximum speed. No control group was included.

“Based on the findings in this study, practitioners and runners can include IST or PT twice a week in their training programme,” the researchers said.