Research
Research
Training and nutrition, backed by research
REZA doesn't sell a training method. We can explain why we do what we do. We follow current scientific literature on strength training, hypertrophy, nutrition, recovery, biomechanics and performance, and critically appraise every study before it reaches your programme.
How REZA appraises research
A large study is not automatically a good study, and a single study is rarely the final word. We weigh factors including study design, sample size, the presence of a control group, risk of bias, effect size and applicability to our target group. Systematic reviews and meta-analyses of RCTs carry more weight than a single study.
REZA Evidence Rating
- A
High confidence
Multiple consistent studies or a strong evidence overview.
- B
Reasonable confidence
A solid systematic review, with caveats.
- C
Interpret with caution
Limited or mixed evidence.
- D
Not suitable as a basis for REZA guidance
A few examples from our knowledge library
Strength training, the big picture
AThe ACSM Position Stand (2026) synthesises 137 systematic reviews and more than 30,000 participants. Strength training improves strength, muscle mass, power and physical function in healthy adults.
Protein and muscle preservation
AA meta-analysis of 49 studies and 1,863 participants (Morton et al.) shows that adequate protein intake gives, on average, a small additional improvement in strength and fat-free mass during prolonged strength training.
Training volume and muscle growth
A/BA meta-analysis of 15 studies (Schoenfeld et al.) shows a relationship between more weekly sets and more muscle growth, though that doesn't mean more is always better.
Training to failure
BResearch by Grgic et al. (15 studies) shows that training to muscular failure is not necessary for gains in strength or muscle size.
New research is added as soon as it genuinely adds to or changes our understanding. Existing insights are not removed automatically; they are replaced once stronger evidence calls for it.