Study Shows Dropping Weight Close to a Competition is Bad

The practise of cutting weight close to a competition is commonplace in many sports including boxing, MMA, swimming, and bodybuilding, but new scientific evidence suggests that this approach could diminish both your performance levels and your body’s immune system. So, is the long-held practice of depleting our energy levels ahead of the most important moments in our lives holding us back? Here’s what you need to know.

How was the study carried out?

A recent study observed 12 female endurance athletes between the ages of 18 and 40. During the trial, the women were first given their optimal number of calories before exercise, with performance levels measured a cycling machine. The same athletes then went on a diet delivering about 50% of their energy requirements and were tested again.

What were the results?

Scientists explained that the practice of going into a competition while on an energy deficit, to cut weight for example, leads to LEA, or “Low Energy Availability.” “Fourteen days of LEA in female athletes increased cortisol levels and had a pronounced effect on the immune system..” said the study authors. “Furthermore, LEA resulted in a sustained impairment in exercise performance.”

Of those who lost weight before being active, athletes lost approximately 4% of their bodyweight, half of which was muscle. “Power output during the 20-min (cycle) time trial was 7.8% lower after LEA,” noted the study. Even after refueling, those were had previously been cutting calories were still 6.7% lower in output, meaning that energy levels take time to return.

What does it all mean?

Athletes who undertake dramatic bulking and cutting phases may consider these results in determining how close they should execute a calorie deficit in relation to their competition date. One example is that of dropping weight before a fight weigh-in. While fighters may qualify for the bout by significantly dropping calories, often by more than 50% (as examined in the study), once the bell rings, they are probably not working to their full potential. Whether flexing on the stage, swimming in a pool, or running track, a marginal performance difference is all it takes to win at an elite level, and so a more deliberate approach to cutting weight further out from a competition and then slowly building back energy levels for the crucial day might be a solid approach worth exploring.

“Among other things, we saw that insufficient energy intake was associated with increased systemic stress,” said the study’s lead author, Jan Sommer Jeppesen, in an interview with sciencedaily.com. “The athletes had a large increase in cortisol, a stress hormone, and a dramatically increased stress level in immune cells. This suggests that there is a quite severe impact on several aspects of the immune system if one doesn’t eat enough. This may potentially contribute to athletes being more exposed to illness.”