Acute Variables: Training Load (Weight and Resistance)

This course discusses the optimal load (a.k.a. weight, resistance, or intensity) for strength training, including the optimal weight for the goals of enhancing strength (e.g. 1 repetition maximum strength, or 1-RM strength), strength endurance (e.g. increasing repetitions to failure), hypertrophy (e.g. muscle growth), and power (e.g. increased velocity and athletic performance). Further, optimal weight recommendations are discussed based on training experience, including novice exercisers, experienced exercisers, athletes, children, and elderly exercisers. Additional topics include the effects of training load on blood chemistry, hormones, markers of muscle growth, cardiovascular changes, bone mineral density, body composition (body fat), electromyography, and rate of perceived exertion (RPE).

Some findings from the included systematic research review resulted in counter-intuitive, or at least less conventional recommendations. For example, endurance strength is likely specific to load (and exercise), training with very heavy loads (1-2 RM/set) may be less effective for improving strength, and training load is likely less influential than performing reps-to-failure/set or increasing training volume for increasing muscle mass (hypertrophy). Additionally, the relationship between acute variables is discussed; for example, the "right weight" when planning a strength training block with conventional repetition tempos, for an athlete that has a primary goal of increasing power (e.g. speed or vertical jump height).

Movement professionals (personal trainers, fitness instructors, physical therapists, athletic trainers, massage therapists, chiropractors, occupational therapists, etc.) should consider acute variables essential knowledge for optimal exercise programming, and training load as one of those acute variables. This course is part of our continued effort to optimize “acute variable” recommendations.

Additional Courses:

• Acute Variables: Repetition Tempo
• Acute Variables: Repetition Range
• Acute Variables: Rest Between Sets
• Acute Variables: Circuit Training
• Acute Variables: Sets per Muscle Group
• Acute Variables: Training Frequency and Recovery Between Sessions

Load Definitions

Based on the methodologies in the research cited in this review.

• Very Heavy: 1-2 RM/set (95 - 100% of 1-RM)
• Heavy: 3 - 8 RM/set (80 - 95% of 1-RM)
• Moderate: 8 - 12 RM/set (70 - 80% of 1-RM)
• Light: 12 - 25 RM/set (50 - 70% of 1-RM)
• Very Light: 25 or more RM/set (50 % of 1-RM or Less)

*RM = repetition (rep) maximum. The maximum number of reps performed before failure (fatigue).

Position Statement: Optimal Training Load (Weight)

• Moderate and heavy loads are likely optimal for most training goals. Moderate and heavy training loads are recommended, and likely the most influential variable for improving strength, with very heavy, light, and very light loads resulting in less or no improvement. Additionally, moderate and heavy loads are likely optimal for improving hypertrophy; however, the load is likely less influential than performing reps-to-failure/set and total training volume. Very light loads with explosive tempos are likely ideal for increasing power (velocity); however, heavier loads result in larger power improvements than lighter loads when comparing strength training with conventional repetition tempos (moderate or slow). Endurance strength is specific to load, and training should aim to increase reps-to-failure/set with a goal/activity-specific load. Last, novice, older, and younger populations should begin training with light or moderate loads, and progress to heavy load training. In summary, cycles of moderate and heavy load training are likely ideal for most training goals. Light and very light loads may only be appropriate for some novice exercisers, while power training with explosive tempos, and/or for some strength endurance goals. Very heavy loads should be reserved for 1 RM practice, and should not be included in regular strength training routines.

Goal-based Recommendations

• Endurance: Light loads (or load-specific)
• Strength: Moderate and heavy loads
• Power: Light loads and very light loads with ballistic tempos (heavy loads during conventional strength training)
• Hypertrophy: Moderate and heavy loads (training volume may be more influential)
• Older Individuals and Children: Light and moderate loads, progressing to heavy loads
  • Load recommendations assume the performance of reps-to-failure/set.

Sample Program:

Experienced Exerciser:

• Goal: Strength
• Split:Full body
• Frequency: 2 - 3 sessions/week
• Routine Construction: Circuit Training
• Periodization: 2-phase block periodization

Phase 1 (4 - 8 weeks):

Acute Variables

• Load: Moderate (70-80% of 1-RM)
• Reps/set: 8-12 reps
• Sets/exercise (circuits): 2-3sets/muscle  group
• Rest between exercises: Circuit training, 1 min rest between exercises
• Training Time: 25 – 45 minutes (excluding warm-up).

Routine

• Legs
  
  • Back squats
• Chest:
  • Incline alternating dumbbell chest press
• Back:
  • Horizontal pull-up
• Shoulders:
  • Curl-to press
• Corrective (Active Rest)
  • Standing Cobra

Phase 2 (4 - 8 weeks):

Acute Variables

• Load: Heavy (80 - 95% of 1-RM)
• Reps/set: 3-8 reps/set
• Sets/exercise (circuits): 3-4 sets/muscle  group
• Rest between exercises: Circuit training, 1 min rest between exercises
• Training Time: 25 – 45 minutes (excluding warm-up).

Routine

• Integrated Exercise
  
  • Front Squat to Press
• Back:
  • Pull-up
• Chest:
  • Bench Press
• Legs:
  • Barbell deadlifts with posterior pull
• Corrective (Active Rest):
  • Standing Cobra to Balance to Calf Raise