The Study
Cardiorespiratory Fitness Improvements Following Low‐Frequency Training Are Not Inferior to High‐Frequency Training Matched for Intensity and Volume
This study is like a fair race between two ways of exercising: doing it twice a week for longer or four times a week for shorter. It found that both ways made people stronger and fitter about the same amount. But it doesn’t prove one way is better — just that neither was worse.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if doing all your weekly exercise in just two big sessions (like Saturday and Sunday) is as good as spreading it out over four smaller ones.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 574 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means you don’t need to exercise every day to get fit; two long, intense workouts a week can give you the same heart and muscle benefits as four shorter ones.
- 2After 8 weeks, both groups improved the same: VO2max went up 10%, muscles got 23% better at using oxygen, blood oxygen-carrying capacity rose 2%, and people could cycle harder for 130% longer.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Scandinavian Journal of Medicine & Science in Sports
Year
2025
Authors
Thomas R. Tripp, Rachel S. Ghitter, H. Kontro, Sarah J. Hargrave, M. Gibala, S. J. Aboodarda, M. MacInnis
Related Content
Claims (10)
Among healthy adults aged 18–45, doing two or four endurance training sessions per week, with the same total volume and intensity, results in the same 10% increase in maximal oxygen uptake after eight weeks.
After eight weeks of endurance training, healthy adults experience a 23% increase in the ability of their skeletal muscles to use oxygen for energy production, whether they train twice or four times per week, as long as the total amount of work and intensity remain the same.
Healthy adults who do eight weeks of endurance cycling training, whether twice or four times a week with the same total effort, can cycle at high intensity for 130% longer before becoming exhausted.
After eight weeks of endurance training, healthy adults experience a 2% increase in hemoglobin mass, whether they train frequently or less often, as long as the total volume and intensity of training are the same.
After eight weeks of endurance training, healthy adults experience lower heart rate, breathing rate, and perceived effort during a fixed-intensity workout compared to before training.
In healthy adults, doing endurance training for eight weeks at the same total volume but spread over either two or four sessions per week results in the same 23% increase in muscle oxygen use and 2% increase in blood hemoglobin mass.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.