Progression Models in Resistance Training for Healthy Adults

Nicholas A. Ratamess, Ph.D.; Brent A. Alvar, Ph.D.; Tammy K. Evetoch, Ph.D., FACSM; Terry J. Housh, Ph.D., FACSM (Chair); W. Ben Kibler, M.D., FACSM; William J. Kraemer, Ph.D., FACSM; N. Travis Triplett, Ph.D.


March 01, 2010

In This Article

Program Design Recommendations for Increasing Muscular Endurance

Local muscular endurance, submaximal local muscular and high-intensity (or strength) endurance, has been shown to improve during RT.[9,59,125,169,255] RT has been shown to increase absolute LME (i.e., the maximal number of repetitions performed with a specific pretraining load),[9,33,125,149] but limited effects are observed in relative LME (i.e., endurance assessed at a specific relative intensity or %1 RM).[172] Moderate to low RT with high repetitions has been shown to be most effective for improving absolute LME in most studies,[9,33,91,125,227] although one study found high-intensity, low-repetition training to be more effective in highly trained endurance athletes.[59] A relationship exists between increases in strength and LME such that strength training alone may improve endurance to a certain extent. However, specificity of training produces the greatest improvements.[9,255] Training to increase LME implies that the individual 1) performs high repetitions (long-duration sets with high muscle time under tension) and/or 2) minimizes recovery between sets.

Exercise Selection and Order

Exercises stressing multiple or large muscle groups have elicited the greatest acute metabolic responses during resistance exercise.[17] Metabolic demand is an important stimulus for adaptations within skeletal muscle necessary to improve LME (increased mitochondrial and capillary number, fiber type transitions, and buffering capacity). The sequencing of exercises may not be as important in comparison to strength training as fatigue (i.e., substrate depletion and accumulation of metabolic waste products) is a necessary component of endurance training.

Evidence Statement and Recommendation.Evidence Category A. It is recommended that unilateral and bilateral multiple- and single-joint exercises be included in a program targeting improved LME using various sequencing combinations for novice, intermediate, and advanced LME training.[9,59,125,169,255]

Loading and Volume

Loading is multidimensional. Light loads coupled with higher repetitions (15-25 repetitions or more) have been shown to be most effective for increasing LME.[9,33,227,255] However, moderate to heavy loading (coupled with short rest periods) is also effective for increasing high-intensity and absolute LME.[9,33] High-volume (including multiple sets) programs have been shown to be superior for LME enhancement.[33,149,169,255]

Evidence Statement and Recommendation.Evidence Category A. For novice and intermediate training, it is recommended that relatively light loads be used (10-15 repetitions).[9,33,227,255]

Evidence Category C. For advanced training, it is recommended that various loading strategies be used for multiple sets per exercise (10-25 repetitions or more) in periodized manner leading to higher overall volume using lighter intensities.[227]

Rest Periods

The duration of rest intervals during resistance exercise appears to affect LME. It has been shown that bodybuilders (who typically train with high-volume and short rest periods) demonstrate a significantly lower fatigue rate in comparison to power lifters (who typically train with low to moderate volume and longer rest periods).[150] These data demonstrate the benefits of high-volume, short rest period workouts for improving LME. It is important to note that another popular method of endurance training is circuit RT. Circuit RT has been shown to increase LME[167,275] and is effective due to its high continuity. Thus, minimal rest is taken between exercises.

Evidence Statement and Recommendation.Evidence Category C. It is recommended that short rest periods be used for LME training, for example, 1-2 min for high-repetition sets (15-20 repetitions or more), < 1 min for moderate (10-15 repetitions) sets. For circuit weight training, it is recommended that rest periods correspond to the time needed to get from one exercise station to another.[167,275]


The frequency for LME training appears similar to hypertrophy training.

Evidence Statement and Recommendation.Evidence Category A. Low frequency (2-3 d·wk−1) is effective in novice individuals when training the entire body.[9,59,125,169,255]

Evidence Category B. For intermediate training, 3 d·wk−1 is recommended for total-body workouts and 4 d·wk−1 is recommended for upper/lower body split routine workouts.

Evidence Category C. For advanced training, a higher frequency may be used (4-6 d·wk−1) if muscle group split routines are used.

Repetition Velocity

Studies examining isokinetic exercise have shown that a fast training velocity, that is, 180°·s−1, was more effective than a slow training velocity, that is, 30°·s−1, for improving LME.[2,186] Thus, fast contraction velocities are recommended for isokinetic training. However, it appears that both fast and slow velocities are effective for improving LME during dynamic constant external RT. Two effective strategies used to prolong set duration are 1) moderate repetition number using an intentionally slow velocity and 2) high repetition number using moderate to fast velocities. Ballor et al.[17] has shown that intentionally slow-velocity training with light loads (5:5 and slower) was more metabolically demanding than moderate and fast velocities. However, Mazzetti et al.[173] showed that explosive CON repetition velocity resulted in greater rates of energy expenditure than a slower velocity (2:2). When matched for intensity and volume, slower velocity may result in greater blood lactates.[173]

Increasing the time under tension with sufficient loading can increase muscular fatigue,[262] and fatigue is important to eliciting LME enhancement. This result was shown by Tran et al.[262] who compared three sets of 10 repetitions (5:5), 10 repetitions (2:2), or 5 repetitions (10:4) and reported that the highest volume load and time under tension, for example, protocol 1, resulted in the largest magnitude of peripheral fatigue. Peak ISOM force (19%) and rate of force development (RFD) (46%) were reduced significantly more than with the other protocols (13-15% and 9-13%, respectively). Thus, traditional velocities may result in less fatigue than slower velocities provided loading is sufficient. However, it is difficult to perform a large number of repetitions using intentionally slow velocities.

Evidence Statement and Recommendation.Evidence Category B. It is recommended that intentionally slow velocities be used when a moderate number of repetitions[10,11,12,13,14,15] are used. Moderate to fast velocities are more effective for increasing repetition number than slow-velocity training.[161] If performing a large number of repetitions (15-25 or more), then moderate to faster velocities are recommended.