Which supplement works better to improve cycling performance: spinach extract or zinc?

Ratings at a Glance

Supplement	Effectiveness Rating	Confidence Rating
Spinach Extract
Zinc

Effectiveness Rating: Spinach Extract vs Zinc

The effectiveness rating is a measure of the supplements' ability to improve cycling performance. This rating answers the question of whether or not a supplement does what it claims. The evidence backing up spinach extract to improve cycling performance is much better than the evidence backing up zinc. Spinach Extract should provide positive results while zinc will not.

Confidence Rating: Spinach Extract vs Zinc

Another factor to take into account when comparing supplements is the confidence rating. This rating is a measure of how valid each supplement's effectiveness rating is. Remember, the confidence rating is a measure of how much you can trust the effectiveness rating. This rating is based on how many studies are included in the database on a supplement's claims. Ideally, you want a high effectiveness AND confidence rating.

Both spinach extract and zinc have low confidence ratings. This means neither supplement has an adequate amount of research to back up this claim. A low confidence rating questions the validity of the effectiveness rating.