Editing Strength training (section)

=== Training volume ===
Training volume is commonly defined as sets × reps × load. That is, an individual moves a certain load for some number of repetitions, rests, and repeats this for some number of sets, and the volume is the product of these numbers. For non-weightlifting exercises, the load may be replaced with ''intensity'', the amount of [[mechanical work|work]] required to achieve the activity. Training volume is one of the most critical variables in the effectiveness of strength training. There is a positive relationship between volume and hypertrophy.<ref name="Schoenfeld2017">{{cite journal |doi=10.1080/02640414.2016.1210197 |title=Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis |year=2017 |last1=Schoenfeld |first1=Brad J|last2=Ogborn|first2=Dan |last3=Krieger |first3=James W |journal=J Sports Sci |volume=35 |pages=1073–1082|pmid=27433992 |issue=11|s2cid=28012566 }}</ref><ref name="Schoenfeld2019">{{cite journal |doi=10.1249/MSS.0000000000001764 |title=Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men |year=2019 |last1=Schoenfeld |first1=Brad J|last2=Contreras|first2=Bret |last3=Krieger |first3=James |last4=Grgic |first4=Jozo |last5=Delcastillo |first5=Kenneth |last6=Belliard |first6=Ramon |last7=Alto |first7=Andrew |journal=Med Sci Sports Exerc |volume=51 |pages=94–103|pmid=30153194 |issue=1 |pmc=6303131}}</ref>

The load or intensity is often normalized as the percentage of an individual's [[one-repetition maximum]] (1RM). Due to muscle failure, the intensity limits the maximum number of repetitions that can be carried out in one set, and is correlated with the repetition ranges chosen. Depending on the goal, different loads and repetition amounts may be appropriate:<ref name="Schoenfeld2021"/>

* Strength development (1RM performance): Gains may be achieved with a variety of loads. However, training efficiency is maximized by using heavy loads (80% to 100% of 1RM). The number of repetitions is secondary and may be 1 to 5 repetitions per set.<ref name="Schoenfeld2021"/>
* Muscle growth (hypertrophy): Hypertrophy can be maximized by taking sets to failure or close to failure. Any load 30% of 1RM or greater may be used. The NCSA recommends "medium" loads of 8 to 12 repetitions per set with 60% to 80% of 1RM.<ref name="Schoenfeld2021"/>
* Endurance: Endurance may be trained by performing many repetitions, such as 15 or more per set. The NCSA recommends "light" loads below 60% of 1RM, but some studies have found conflicting results suggesting that "moderate" 15-20RM loads may work better when performed to failure.<ref name="Schoenfeld2021">{{cite journal |last1=Schoenfeld |first1=Brad J. |last2=Grgic |first2=Jozo |last3=Van Every |first3=Derrick W. |last4=Plotkin |first4=Daniel L. |title=Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum |journal=Sports |year=2021 |volume=9 |issue=2 |page=32 |doi=10.3390/sports9020032 |pmid=33671664 |pmc=7927075 |issn=2075-4663|doi-access=free }}</ref>

Training to muscle failure is not necessary for increasing muscle strength and muscle mass, but it also is not harmful.<ref name="Grgic2022">{{cite journal |doi=10.1016/j.jshs.2021.01.007 |title=Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis |year=2022 |last1=Grgic |first1=Jozo|last2=Schoenfeld|first2=Brad J |last3=Orazem |first3=John |last4=Sabol |first4=Filip |journal=J Sport Health Sci |volume=11 |pages=202–211|pmid=33497853 |issue=2 |pmc=9068575}}</ref>