One thing I know for sure: tongkat ali is a strong enhancer of athletic performance.

I am beyond 50, and when I have taken my daily dosage of 1 gram of 1:50 tongkat ali extract, I do double the number of pull-ups, compared to when I am tongkat ali sober.

The strength gain is greatest after the second day of a tongkat ali cycle, and it lasts for about two additional days after I have ended a tongkat ali cycle.

That water-based tongkat ali extract changes body composition in men from fat to lean body mass has been confirmed in a human clinical trial.

This study was published in the Britisch Journal of Sports Medicine.

The scientific index for this study is:

Br J Sports Med.2003; 37: 464-470

The strength gain is greatest for the kind of exercise that requires muscle strength: pull-ups or running up stairs (an exercise form I personally prefer). There is less benefit from tongkat ali for exercise that is more on endurance, rather than strength, for example distance running over flat terrain.

I think it would be most interesting to do a scientific study on the athletic performance enhancing effect of tongkat ali. Initially, a test utilizing an animal model would be appropriate, e.g. a forced swim test for mice. In such a test, it could easily be determined and measured what effect tongkat ali has on athletic performance.

I have checked with Sumatra Pasak Bumi (website tongkatali.org) whose 1:50 extract I use myself. They assured me that they would provide (free of charge) as much extract as might be needed for scientific studies.