Performance
B · Reasonable confidenceDoes interval training alongside lifting reduce strength or growth?
Subject: The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis
What this means
Interval training combined with strength training gave the same muscle growth and upper body strength as strength training alone. Leg strength increased slightly less (effect size -0.248).
Sabag A, Eather N, Naclerio F, Martinez M, Hidayat M, Haff GG, Nosaka K · 2018 · European Journal of Sport Science
What does this rating mean?
A solid systematic review with caveats, or consistent indications with a limited scope.
Findings
Concurrent HIIT and resistance training did not significantly interfere with strength or hypertrophy compared to resistance training alone. Cycling-based HIIT showed less interference than running, supporting compatibility when properly programmed.
Who this applies to
Multiple studies; trained and untrained adults
What to keep in mind
That cycling in particular held back leg strength was only a trend that was not statistically certain. The abstract does not report the number of studies or participants.
Practical conclusion for REZA
Clients combining HIIT and resistance training don't need to worry about losing strength or muscle — cycling as the cardio mode shows slightly less interference than running.
View method and source
Methodology
Meta-analysis
Intervention
Concurrent HIIT + RT vs RT alone
Outcome measures
Muscular strength, muscle hypertrophy
Limitations
Limited number of studies; heterogeneity in HIIT protocols; mostly untrained populations.
Original source
DOI: 10.1080/02640414.2018.1464636
View the publication →Physical Activity, All-Cause and Cardiovascular Mortality, and Cardiovascular Disease: A Systematic Review and Meta-Analysis of Multiple Health Outcomes
Next study →Exercise/Physical Activity in Individuals with Type 2 Diabetes: A Consensus Statement from the American College of Sports Medicine
This information is general education about scientific research. It is not personal medical advice and does not replace diagnosis or treatment by a doctor or other healthcare professional. If you have symptoms, a medical condition or take medication, consult your GP or treating professional before changing your training or nutrition.