Many of us have been there: we get done with a grueling round of rolling or a tough match at a competition and head to the sidelines to drink some water and rest by standing bent over with our hands on our knees. Many a coach (jiu-jitsu and otherwise) has “corrected” their students by insisting they stand up straight and keep their hands behind their head, assuming it was a better recovery position. But a study from last year that is now resurfacing has actually shown that the “hands on knees” position may be superior than the “hands on head” position we’ve all been pushed to use over the years.
The study, published in February 2019 in the Translational Journal of the American College of Sports Medicine, saw twenty female Division II varsity soccer players engage in four minutes of high-intensity running, followed by three minutes of rest. The participants were given specific instructions on what position to take during the rest period, which amounted to either the familiar hands on the head (HH) or hands on the knees (HK) positions. The participants repeated the experiment with the opposite recovery position the following day.
The results show why our bodies naturally gravitate toward the HK position when we’re exhausted: there was a significant improvement in recovery time when participants stood with their hands on their knees instead of above their head.
So what’s the science behind these results? Here’s the reasoning given by the study:
“HK posture causes thoracic flexion and internal rotation of the rib cage, which has been reported to optimize the diaphragmatic zone of apposition (ZOA) (18,19). Optimizing the ZOA allows the diaphragm to operate with maximal efficiency (8). This could explain the greater cardiorespiratory response seen in the HK condition, which has been reported in individuals experiencing chronic obstructive pulmonary disease and their reduced feelings of dyspnea (20,21,22).”
And if your old coach has ever insisted that the HH position would “open up your lungs,” the study says that the truth about this position is that it hinders your short-term recovery. “HH posture promotes thoracic extension, which is associated with external rotation of the rib cage and reduced ZOA (8). This mechanical linkage between the diaphragm and ribcage (23) could explain why individuals had a higher HRR after the recovery periods in the HK versus HH postures,” said the study.
“HH posture places the diaphragm in a suboptimal position, decreasing its mechanical efficiency. A decrease in the ZOA reduces the ability of the diaphragm to contract effectively because of its poor position along its length–tension curve (10,12). Elevating the arms to 90° or more of shoulder flexion, as observed with HH posture, changes the impedance of the torso, rib cage, and abdominal wall (24,25,26). Raising the arms causes a passive stretch of the thoracic wall and abdominal muscles (overlengthened position), which may place them in a less effective position for assisting in respiration.”
To summarize: if you feel the need to stand with your hands on your knees after getting walloped by the gym’s resident butt-kicker, trust your body’s instincts, because they’re probably right.
