Previous studies have linked the early decrease in muscle strength after ST to neural fatigue and muscle acidosis (Byrne. 2004, Crewther. 2006; Sahlin. 1998). The long-lasting reduction of muscle strength for several hours or days or days after your workouts, however, is primarily associated with muscle damage (Nosoka. 2002 & 2005, Roth. 1999).
In rookies, Flores et al. (2011) have been able to show that even 10 sets of curls can decrease the elbow flexor (=biceps) strength below baseline levels for more than 95 hours, i.e. four full days!
|Figure 1: While the peak torque recovered only slowly in the 2011 study by Flores, the deep-onset-muscle-soreness (DOMS) returned to (almost) baseline on day four after 10 sets of biceps curls (Flores. 2011).|
To investigate the time course of muscle recovery after single- and multi-joint strength exercises, sixteen highly resistance trained men performed two exercise protocols in the same day using a contra-lateral counterbalanced design:
- 8 sets of 10 repetitionmaximum (RM) of unilateral seated row, and
- 8 sets of 10 RM unilateral bicep curls using the contralateral arm.
Do we actually know something about training twice a day? While we do know that Arnold loved doing that we don't have reliable scientific evidence of the efficacy or inefficacy of training in the AM and PM (both strength training). There is some data from endurance training studies (e.g. Yeo. 2008), but this data is about as irrelevant for you and me as the fact that doing AM/PM training obviously worked for Arnold ;-)In subsequent visits, subjects performed the exercise protocols, while maximal peak torque and DOMS were measures before, 10 minutes, 24, 48, 72 and 96 hours post exercise. To avoid circadian
influences, subjects were asked to visit the laboratory always at the same time of day. To reduce confounding factors, the volunteers were not allowed to perform any vigorous physical activities or unaccustomed exercise during the experiment period. They were also instructed not to intake medications or supplements during the study period.
|Figure 2: Due to being more targeted, the single-joint exercise lead to a higher acute decrease in peak torque. The overall torque recovery, however, was equally fast in both groups (Soares. 2015).|
Interestingly enough, the "classic" arms-day (simulation) which is often considered to be a perfect interlude between "heavy days" a "bro" can use to recover lead to significant decreases in peak torque that lasted for more than 24h(!) and were in line with a significantly more pronounced increase in DOMS that declined to normal within 96h only regardless of whether the subjects performed the multi- or single-joint exercise.
- Byrne, Christopher, Craig Twist, and Roger Eston. "Neuromuscular function after exercise-induced muscle damage." Sports medicine 34.1 (2004): 49-69.
- Crewther, Blair, et al. "Possible stimuli for strength and power adaptation." Sports medicine 36.3 (2006): 215-238.
- Flores, Débora F., et al. "Dissociated time course of recovery between genders after resistance exercise." The Journal of Strength & Conditioning Research 25.11 (2011): 3039-3044.
- Nosaka, Kazunori, and Mike Newton. "Difference in the magnitude of muscle damage between maximal and submaximal eccentric loading." The Journal of Strength & Conditioning Research 16.2 (2002): 202-208.
- Nosaka, Kazunori, et al. "Partial protection against muscle damage by eccentric actions at short muscle lengths." Medicine and science in sports and exercise 37.5 (2005): 746-753.
- Radaelli, Regis, et al. "Time course of strength and echo intensity recovery after resistance exercise in women." The Journal of Strength & Conditioning Research 26.9 (2012): 2577-2584.
- Roth, Stephen M., et al. "Ultrastructural muscle damage in young vs. older men after high-volume, heavy-resistance strength training." Journal of Applied Physiology 86.6 (1999): 1833-1840.
- Sahlin, Kent, Michail Tonkonogi, and Karin Söderlund. "Energy supply and muscle fatigue in humans." Acta physiologica Scandinavica 162.3 (1998): 261-266.
- Soares, Saulo, 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).
- Yeo, Wee Kian, et al. "Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens." Journal of Applied Physiology 105.5 (2008): 1462-1470.