Protease Supplementation: First Evidence That 1,000mg Bromelain Have Ergogenic Effects in Athletes - Decreased Fatigue & Maintenance of Testosterone During Competition

You won't see the same effects with pineapple/juice (Aiyegbusi. 2011).

Proteases are as any Wikipedia user will lean enzymes that break down proteins (proteolysis) by hydrolyzing the peptide bonds that link amino acids together in the polypeptide chain forming the protein.

Proteases have evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Proteases can be found in animals, plants, bacteria, archaea and viruses. And proteases can be found on among the favorite supplements of naturopath.
Up to today, however proteases could not be found on the list of scientifically proven performance enhancers. With the latest study from the University of Tasmania, the latter has changed: According to the results Shing et al. published in the latest issue of the European Journal of Sport Science, bromelain, a protease that can be found among others in several foods, most prominently pineapple, can reduce (a) the subjective feelings of fatigue and (b) help to maintain testosterone concentration in competitive cyclists taking part in a six-day cycle stage race.

The former is what Shing et al. conclude based on the results of a study that involved fifteen highly trained cyclists [age: 22, years, height: 1.79, body mass: 68.69]. In the corresponding randomized, double-blind, placebo-controlled trial

• 8 of the cyclist 1000mg of bromelain per day, while
• 7 of the cyclists got a visually identical placebo supplement

which was consumed daily across six days of competitive racing. Blood was collected from each cyclist on days one, three and six of racing and analysed for creatine kinase (CK), myoglobin, lactate dehydrogenase (LDH) and testosterone.

Figure 1: Changes in CK and testosterone during the 6 days of competitive cycling (Shing. 2015).

The results of the study show significant elevations in CK activity (this protein is indicative of muscle damage), LDH activity (this protein is necessary to get rid of lactate) and myoglobin concentration in both groups. What was different, though was that the testosterone concentrations of the athletes who received the bromelain supplement tended to maintain stable, while those of the subjects in the placebo group decreased significantly over the course of the 6-day race period.

In conjunction with the perceived feeling of fatigue with was lower in the bromelain group on day four of racing (P = 0.01), the results of the study at hand to this in fact suggest that the consumption of 1,000mg of bromelain can have beneficial effects on some, albeit not directly performance relevant parameters in trained athletes.
References:

• Aiyegbusi, Ayoola I., et al. "A comparative study of the effects of bromelain and fresh pineapple juice on the early phase of healing in acute crush achilles tendon injury." Journal of medicinal food 14.4 (2011): 348-352.
• Pavan, Rajendra, Sapna Jain, and Ajay Kumar. "Properties and therapeutic application of bromelain: a review." Biotechnology research international 2012 (2012).
• Shing, Cecilia M., et al. "Acute protease supplementation effects on muscle damage and recovery across consecutive days of cycle racing." European journal of sport science ahead-of-print (2015): 1-7.