Sometimes the hardest part of exercise is finding the time. Between work, family, and everyday stress, long workouts often feel impossible to fit in. But what if just a few minutes of effort could deliver real results?

A new study from researchers in China looked at sprint interval training (SIT) and found that even short, high-intensity sessions can improve endurance and performance. Here, we’ll look at what sprint intervals are, what the research uncovered, and how you can put this method into practice without needing hours at the gym.

A short workout with big effects: what the study found

The research compared sprint interval training to traditional long-distance running. Twenty male distance runners, all well-trained athletes, took part. Over six weeks, one group followed a sprint interval program while the other stuck with steady endurance training. Both groups trained twice per week in addition to their regular running schedule.

The sprint group completed sessions built around repeated 30-second maximum sprints, with about three and a half minutes of rest in between. This format—short bursts of speed followed by longer recovery—pushed athletes close to their limits, engaging both aerobic and anaerobic energy systems. The traditional training group, on the other hand, did longer steady runs and repeats at moderate intensity.

The results were clear. The sprint group improved significantly in several key areas: time to exhaustion, short-distance sprint performance, and even a 3000-meter run. The endurance group only showed a small gain in one sprint distance. While changes in VO2 max (the amount of oxygen your body can absorb) and running economy were modest, the effect sizes suggested meaningful physiological benefits from sprint intervals.

How to add sprint intervals to your training

The appeal of sprint interval training is that it delivers a big impact in very little time. If you want to try it safely and effectively, make sure to follow these tips:

Warm up first: Spend 5–10 minutes jogging or cycling at an easy pace, adding a few light strides or accelerations to prep your muscles.
Sprint hard: Run, bike, or row at maximum effort for about 30 seconds. This should feel close to all-out.
Recover fully: Rest or move slowly for 3–4 minutes. Your heart rate should drop back down before the next sprint.
Repeat: Do 4–6 sprints in a session. Beginners can start with fewer and build up.
Cool down: Finish with 5 minutes of light movement to bring your body back to baseline.

If you’re new to high-intensity workouts, start cautiously and consider talking to a trainer or doctor, especially if you have existing health concerns. Sprint intervals are demanding, and proper recovery between sessions is key. Two SIT workouts per week are enough for most people, especially if combined with regular moderate activity.

Sprint interval training shows that fitness doesn’t have to mean hours of effort. With focused bursts of energy, you can strengthen your heart, improve endurance, and boost performance. For busy people or athletes looking for an edge, it’s a practical, time-efficient way to get results.