Sprint interval training (SIT) involves intense bursts of exercise followed by short periods of rest. A recent study looked into the specific details of SIT, such as duration and repetitions, and how they affect the body. The findings can help in creating customized sprint training programs that are beneficial for people today. Activities like jogging, walking, cycling, and sprinting all engage the musculoskeletal system and have various physiological effects.energy utilization, sprint interval training (SIT) has gained attention for its intense exercise cycles followed by short rest periods. The structure of these exercise and rest durations can impact SIT’s effects on physiological responses. Lately, sports physiology has seen a growing interest in optimizing SIT protocols, which can help improve athletic performance and overall well-being. This surge in interest can enhance the recognition of SIT as a versatile tool for promoting health and fitness.SIT, a team of researchers from Japan, including Dr. Takaki Yamagishi from the Department of Sport Science and Research at the Japan Institute of Sports Sciences, and Professor Yasuo Kawakami from the Human Performance Lab at Waseda University, conducted SIT experiments with healthy human volunteers. Their study was published online in the Medicine & Science in Sports & Exercise journal on March 7, 2024. Yamagishi explains the motivation behind their research, stating “EThe main focus of my research has been to determine the minimum amount of exercise needed to see benefits, such as improved aerobic fitness. With the support of Prof. Kawakami and other co-authors, as well as collaboration with Waseda University, we were able to conduct a unique study using a comprehensive approach.
Our team of researchers compared two different sprint interval exercises (SIE) with the same total sprint duration and sprint-to-rest ratio. We studied the impact of SIE on physiological and metabolic responses by analyzing pulmonary oxygen uptake (V̇O2) levels and changes in tissue oxygenation.The researchers conducted a study to measure the impact of sprint interval exercise (SIE) on thigh muscles, using ∆TOI and T2-weighted MRI technique for assessment. They found that SIE20, consisting of two 20-second sprints with 160-second recovery, was more effective than SIE10, which involved four 10-second sprints with 80-second recovery. Both SIE protocols significantly increased whole-body and peripheral oxidative metabolism, as well as activation of the major thigh muscles. This was confirmed by increases in V̇O2 levels, ∆TOI and MRI T2 values.The researchers found that participants had higher aerobic and metabolic responses with SIE20 compared to SIE10. They also found that doing more sprint repetitions in SIE10 did not lead to greater oxidative metabolism.
Yamagishi explained the real-world implications of the research, stating that “In today’s fast-paced world, lack of time is a major barrier to regular physical activity. However, the exercise methods used in our study take less than 15 minutes to complete and offer significant health benefits.”
To summarize, this study’s findings help fill important research gaps in SIT, including the effects of minimum sprint duration and repetitions on aerobic and metabolic responses.Yamagishi, Iwata, and Shiose (2021) conducted a study on the effects of sprint interval training (SIT) on physiological responses in humans. Their research indicates that low-volume SIT has the potential to enhance training programs and exercise regimens. Yamagishi expressed optimism that their study could contribute to the updating of exercise guidelines by organizations such as the American College of Sports Medicine. Additionally, he suggested that future research on sprint interval exercise (SIE) could use their findings to establish the relationship between exercise volume, intensity, and training adaptations.
