Some fresh research. Important stuff in bold.
Interesting and practically useful study on the implications of rep speed:
Resistance training with slow speed of movement is better for hypertrophy and muscle strength gains than fast speed of movement. International Journal of Applied Exercise Physiology 5.2 (2016): 37-43.
Repetition speed is an important variable during resistance training. However, the effects of different speeds on the muscular strength and hypertrophy in isotonic resistance training are not clear. The study compared fast speed with slow speed of isotonic resistance training on muscular strength and hypertrophy in well-trained adults. Twelve healthy adults were randomly assigned into two groups: fast speed (FS) and low speed (SS). Muscle hypertrophy was measured by an ultrasound examination of the cross-sectional area of the brachial biceps muscle. Muscular strength was verified by 1 RM test. To check the possible differences in strength and hypertrophy between pre and post training and between groups there were compared by two-way ANOVA for repeated measurements and the effect size (ES) was calculated. Improvement in the cross-sectional area (P=0.019) and muscular strength (P=0.021) in the SS group between pre and post training was verified. The SS group had bigger effect sizes than FS group for hypertrophy and strength from pre to post training. SS training was more effective to improve hypertrophy and muscle strength in well-trained adults.
The FS group performed repeating the following cadence: 1s in the concentric phase, 0s in the transitional phase from the concentric for the eccentric phase, 1s in the eccentric phase and 0s in the transitional phase from the eccentric to the concentric phase (1010). The SS group performed the repetitions with 1s in the concentric phase, 0s in the transitional phase from the concentric for the eccentric phase, 4s in the eccentric phase and 0s in the transitional phase from the eccentric to the concentric phase (1040).
And another study on cardio, specifically HIIT vs traditional slow pace cardio.
PLoS One. 2016 Apr 26;11(4):e0154075. Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment.
We investigated whether sprint interval training (SIT) was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training (MICT). SIT involved 1 minute of intense exercise within a 10-minute time commitment, whereas MICT involved 50 minutes of continuous exercise per session.
Sedentary men (27±8y; BMI = 26±6kg/m2) performed three weekly sessions of SIT (n = 9) or MICT (n = 10) for 12 weeks or served as non-training controls (n = 6). SIT involved 3x20-second 'all-out' cycle sprints (~500W) interspersed with 2 minutes of cycling at 50W, whereas MICT involved 45 minutes of continuous cycling at ~70% maximal heart rate (~110W). Both protocols involved a 2-minute warm-up and 3-minute cool-down at 50W.
Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both). Insulin sensitivity index (CSI), determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002) and MICT (5.0±3.3 to 6.7±5.0 x 10-4 min-1 [μU/mL]-1, p = 0.013) (p<0.05). Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001). The corresponding changes in the control group were small for VO2peak (p = 0.99), CSI (p = 0.63) and CS (p = 0.97).
Twelve weeks of brief intense interval exercise improved indices of cardiometabolic health to the same extent as traditional endurance training in sedentary men, despite a five-fold lower exercise volume and time commitment.