|As usual, there is no one size fits it all answer when it comes to the "optimal" inter-workout rest times - 72h in-between workouts w/ compound movements does yet seem reasonable.|
As general guidelines, the National Strength and Conditioning Association (NSCA) states that increased recovery time is needed between heavy lifting days and that upper body musculatures recovers faster than lower body musculature and single joint lifts require less recovery time than multi-joint lifts (NSCA. 2008).
Korak et al.'s "careful review of the literature cited in the NSCA guidelines" does yet reveal that most of the references are based on anecdotal evidence in older review papers or other textbooks and no quantitative evidence of recovery patterns were collected in the investigations cited supporting upper body versus lower body recovery or single versus multi-joint lift recovery.
"Recent investigations have sought to quantitatively determine the number of days needed for recovery to occur. While these investigations have extended the knowledge concerning lifting recovery as a whole, they have not delineated if discrepancies exist between multi-joint, single-joint, upper body, and lower body" (Korak. 2015).Accordingly, Korak et al. conducted a study that was designed to quantify muscle recovery patterns between single- (SJ) and multi-joint (MJ), and upper body (UB) and lower body (LB) exercises at 24 and 48 h.
|Table 1: Overview of the lifting protocol used in the study at hand (Korak. 2015)|
How much recovery is actually needed between two resistance training sessions?
To this ends, 10 recreationally strength trained college age males (26 ± 6 years) were recruited. The subjects had to complete 2 sets of 10 exercises. At an intensity equal to 85% of their 10-RM they had to perform 8 reps for first set of the exercise, which was intended to induce standardized fatigue before the subsequent set to failure. For the second they performed 10 reps to failure at the predetermined 10-RM.
"The protocol was replicated during two additional sessions with days of rest (either 24 or 48h) between the next two lifting sessions serving as the independent variable. A counter-balanced crossover design was used. Half of the participants repeated their workout 24 h after the baseline session and rested for 48 h before their fourth and final session (e.g. baseline Monday, 24 h session on Tuesday, and 48 h session on Thursday). The other half completed their third session 48 h after baseline testing and their fourth and final session 24 h later (e.g. baseline Monday, 48 h session on Wednesday, and 24 h session on Thursday). Participants were instructed to refrain from other exercise, alcohol, and to maintain regular diet and sleeping patterns from 48 h prior to their baseline testing session until completion of the study" (Korak. 2015).The same sequence of exercises was incorporated in the baseline and all treatment sessions. All participants completed 10 different exercises. Resistance exercises included: flat barbell bench press (BP), seated dumbbell military press (MP), barbell dead lift (DL), machine leg press (LP), knee extension (KE), machine triceps extension (TE), dumbbell side raises (SR), machine chest fly (CF), and seated machine hip abduction/adduction (HipAB/AD).
|McLester et al. found similar results - Full recovery from all exercises was achieved only after 72h. With leg extensions it was yet not a compound, but an isolation exercise which had the longest recovery times (McLester. 2003).|
What all three studies (McLester, Jones & Korak) have in common, though, is that a recovery time of only 24h was not sufficient for full recovery in the vast majority of the trained (Jones & Korak) and untrained, but healthy (McLester) subjects.
- the performance decline was most pronounced for the multi-joint movements (BP, MP, DL, LP) and least pronounced if not non-existent for the single joint exercises,
- there was a tendency for the lower body to recover faster than the upper body that stands in contrast to the broscientific advice that training legs would require longer recovery periods,
- the recovery after lower body exercises was in fact so rapid that there was a measurable supercompensation effect (=subjects did more reps than before) even after only 48h of recovery in a handful of subjects.
- Jones, Eric J., et al. "Stability of a practical measure of recovery from resistance training." The Journal of Strength & Conditioning Research 20.4 (2006): 756-759.
- Korak, John A., James M. Green, and Eric K. O'Neal. "Resistance Training Recovery: Considerations for Single vs. Multi-joint Movements and Upper vs. Lower Body Muscles." International Journal of Exercise Science 8.1 (2015): 10.
- McLester, John R., et al. "A Series of Studies---A Practical Protocol for Testing Muscular Endurance Recovery." The Journal of Strength & Conditioning Research 17.2 (2003): 259-273.
- National Strength and Conditioning Association. Essentials of Strength and Conditioning-3rd Edition. Champaign, IL: Human Kinetics, 2008.