The Pros and Cons of Training a Muscle Failure
Research has shown that performing multiple sets is superior to single sets (1, 2). For example, if you perform 3 sets 8 squats you will achieve greater strength gains than if you only did 1 set of 8. However it is unclear if performing resistance exercise sets to muscular failure is necessary to achieve optimal strength and increase muscle mass. In Willardson’s (2007) review paper, muscular failure is defined as “the point during a resistance exercise set when the muscles can no longer produce sufficient force to control a given load.” I’m sure you know exactly what that feels like…you feel like jello, eyeballs popping out, and neck veins distended!
Before we get into the pros/cons lets review the variables to be considered when designing a resistance training program for optimal strength and hypertrophy (2).
- Type of muscle action: both concentric and eccentric.
- Load – must be at least 70-85% of 1-RM (see muscular strength).
- Strength Sets: moderate to low 3 – 5 sets of 2 – 8 reps.
- Hypertrophy Sets: high to very high 3-6 sets of ~10 reps.
- Exercise selection – core, structural, and assistance exercises
- Exercise order – multi-joint to single joint.
- Rest periods – 30s-90s for hypertrophy and 1-3min for strength.
- Velocity of muscle action – slow speed for strength or fast speed for power.
- Frequency of training per week: 2-3x/week
Pros to training a muscle to failure:
- Greater activation of motor units – When you train to failure you recruit more of your fast twitch (or fast glycolytic) motor units. Remember that fast twitch motor units are your strongest and fastest and so are capable of the greatest increases in strength and hypertrophy. Therefore, in order to get stronger you must recruit your fast twitch fibers! Training at lighter loads (< 80% 1RM) you are not recruiting your fast twitch fibers and so would limit your ability to increase strength (3, 5, 6, 7, 8).
- Increase secretion of growth hormones. Hormones responsible for increased protein synthesis to increase muscle cross-sectional area are: insulin growth factor -1, human growth hormone, testosterone. During the short-term (4-6 weeks) these hormones where shown to be higher after performing resistance exercise sets to muscular failure. However, as sets to failure continued over the long-term (16-weeks) the secretion of growth hormones declined and cortisol level increased (4)!
Cons to training a muscle to failure.
- Long term (16-weeks) decreases in growth hormone and increased cortisol levels. A study that looked at the long-term training effects of muscular failure resulted in a decrease in growth promoting hormones and increases in catabolic hormone cortisol. This would cause a loss in strength, muscle mass, and lead to overtraining (Izquierdo et al 2006).
- High potential for overtraining and overuse injuries due to the highly stressful nature of training to failure (8).
- Not a good way to train for maximal power production: fast speed strength must be trained explosively. When you are performing reps to failure your velocity slows and this is not an effective stimulus to improve power (2,8).
Recommendations for Training to Muscular Failure:
- Training to failure would provide the necessary stimulus to break through strength plateaus if done in the short term -> no more than 6 weeks.
- Vary weekly intensity to avoid overtraining: Heavy day, light day, medium day.
- Alternate failure weeks with non-failure weeks:
- Week 1 – Train 2 days but train to failure.
- Week 2 – Train 3 days but DON’T go to failure.
- For older adults and individuals who lift weights for the purpose of improving physical function there is NO reason to train to failure.
1. ACSM: progression models in resistance training for healthy adults. Med Sci. Sports Exercise 34:364-380 2002.
2. Baechle TR, Earle RW. Essentials of Strength Training and Conditioning. Human Kinetics. 2008 pp. 382-411.
3. Drinkwater EJ, Lawton TW, Lindsell RP, Pyne DB, Hunt PH, McKenna MJ. Training leading to repetition failure enhances bench press strength increases in elite junior athletes. J Strength and Cond Res. 19: 382-388. 2005
4. Izquierdo MJ, Ibanez JJ, Gonzalez-Badillo K, Hakkinen NA, Ratamess WJ, Draemer DN, French J, Eslava A, Altadill X. Differential effects of strength training leading to failure vs. not to failure on hormonal responses, strength and muscle power increases. Journal of Applied Physiology. 100:1647-1656. 2006
5. Rooney KJ, Herbert RD, Balnave RJ. Fatigue contributes to the strength training stimulus. Medicine Science in Sports and Exercise. 26:1160-1164. 1994,
6. Sanborn KR, Hruby BJ, Schilling B, O’Bryant HS, Johnson RL, Hoke T, Stone ME, Stone MH. Short-term performance effects of weight training with multiple sets not to failure vs. a single set to failure in women. J Strength Cond. Res. 14:328-331. 2000.
7. Schott J, McCully K, Rutherford OM. The role of metabolites in strength training: Short vs. long isometric contractions. European Journal of Applied Physiology. 71:337-341. 1995.
8. Willardson JM. The Application of training to failure in periodized multiple-set resistance exercise programs. Journal of Strength and Conditioning Research 21(2): 628-631. 2007.