How often should you be working out, and how long should we rest? Adapting to training is all about the balance between recovering and training.
As discussed in our previous article, “Why Your Muscles Are Sore After Exercise,” how sore you are may not be the best indicator of recovery. One very useful marker to determine if you’ve recovered is a decrease in muscle strength and endurance that lingers for a day or more after a workout (1; 2).
Historically, exercise scientists thought recovery from workouts depended on neural fatigue and muscle acidosis (3-5). But, the longer-lasting reduction in training performance for several hours or days after training appears to be from damage to the muscle cells (6). This is where the question of “how long you’ve been training” really comes into play.
For instance, if a person is just starting training, it can take a trained muscle group up to four days to properly recover before being ready to train again (1). On the other hand, for someone much more experienced, this time frame can change dramatically.
Research on experienced trainers has lagged greatly; however, a major study investigating muscle recovery in highly trained subjects was published recently (7). In a collaborative research effort, exercise scientists from both the University of Brasília and California State University, Fullerton, investigated the time course of muscle recovery after single- and multi-joint strength exercises in 16 highly resistance-trained men. They performed two exercise protocols in the same day doing eight sets of 10 max reps of a seated row (multi-joint) and eight sets of 10 max reps of a bicep curl (single-joint).
The subjects performed the exercises while the researchers measured maximal peak torque and muscle soreness before exercise, during exercise after 10 minutes, and 24, 48, 72, and 96 hours after exercise. To increase accuracy of the study, the subjects were not allowed to perform any hard physical activities or exercise during the experiment. They were also not allowed to use supplements like whey protein that could affect recovery times during the study period.
Interestingly, the highly trained subjects went right back to their normal performance in just one day on the row exercise (multi-joint), where the powerful back muscles and the biceps work together. The curl exercise took longer to recover from, demonstrating that more advanced trainees can expect to recover faster from multi-joint exercises.
In summary, if you’re new to more intense exercise, it can take 72 to 96 hours before you should train the same movement or body part again. In contrast, those who are well trained can recover to full strength levels in as little as a day after doing multi-joint exercise and within two days after doing single-joint exercises. Remember that muscle soreness is not the best gauge for recovery; instead, look to performance and strength levels. In general from the recent research, experienced trainees should wait one-to-two days before doing a similar workout, while those just starting should hold off for three-to-four days.
- Flores DF, Gentil P, Brown LE, Pinto RS, Carregaro RL, Bottaro M. Dissociated time course of recovery between genders after resistance exercise. The Journal of Strength & Conditioning Research 2011;25:3039-44.
- Eston RG, Finney S, Baker S, Baltzopoulos V. Muscle tenderness and peak torque changes after downhill running following a prior bout of isokinetic eccentric exercise. Journal of Sports Sciences 1996;14:291-9.
- Byrne C, Twist C, Eston R. Neuromuscular function after exercise-induced muscle damage. Sports Medicine 2004;34:49-69.
- Crewther B, Keogh J, Cronin J, Cook C. Possible stimuli for strength and power adaptation. Sports Medicine 2006;36:215-38.
- Sahlin K, Tonkonogi M, Soderlund K. Energy supply and muscle fatigue in humans. Acta physiologica Scandinavica 1998;162:261-6.
- Roth SM, Martel GF, Ivey FM et al. Ultrastructural muscle damage in young vs. older men after high-volume, heavy-resistance strength training. Journal of Applied Physiology 1999;86:1833-40.
- Soares S, Ferreira-Junior JB, Pereira MC et al. DISSOCIATED TIME COURSE OF MUSCLE DAMAGE RECOVERY BETWEEN SINGLE AND MULTI-JOINT EXERCISES IN HIGHLY RESISTANCE TRAINED MEN. Journal of Strength and Conditioning Research/National Strength & Conditioning Association 2015.