Restricting blood flow after sprint interval training increases aerobic capacity

Training with low-load weights and blood flow restriction - a technique known as Kaatsu training - increases strength and is particularly valuable during rehab training. Restricting blood flow causes metabolic stress, which triggers rapid adaptations.

Scientists from Longhborough University in England extended this concept by restricting blood flow to the leg muscles after repeated cycling sprint training. The subjects performed repeated 30-second sprint intervals at maximum effort on a cycle ergometer followed by restriction of blood flow to the leg muscles two days a week for four weeks. They showed an increase in maximal oxygen consumption compared to a group performing interval training without blood flow restriction, but no improvements in timed 15-kilometer cycling. Muscle biopsies showed that reducing blood flow after exercise also increased levels of a chemical associated with increased capillary density.

This study is a potential milestone. A timed 15 kilometer ride on a road bike requires specific motor skills that may not improve within 4 weeks. We can conclude from the dramatic changes in maximal oxygen consumption and muscle vascularization that post-exercise blood flow restriction is a viable training technique.

(Experimental Physiology, 101: 143 - 154, 2016)