Little Byte Summary: Short sprints at timed intervals can help you get the same health benefits in less time than longer-duration exercise sessions.
Researchers in Norway conducted a small study comparing 12 weeks of a medium-intensity, 50 minute, cycling workout with a 3×20 second “max” sprint workout (1 minute total), in which the sprints were interspersed with 2 minutes of low intensity cycling. The latter workout had a 10 minute time commitment.
Here are the results (MICT is the 50 minute workout, SIT is the short sprints):
Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both). Insulin sensitivity index (CSI), determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002) and MICT (5.0±3.3 to 6.7±5.0 x 10−4 min-1 [μU/mL]-1, p = 0.013) (p<0.05). Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001). The corresponding changes in the control group were small for VO2peak (p = 0.99), CSI (p = 0.63) and CS (p = 0.97).
In other words, the health benefits were largely the same in both groups.
The largest difference lies in the time commitment and intensity.
There are shortcomings to the study (size, health metrics etc.), but hats off to the researchers for exploring this hypothesis that can save you time.