The current study analyzed the excitation of biceps brachii, brachioradialis, and anterior deltoid during bilateral biceps curl performed with different handgrips. Ten competitive bodybuilders performed bilateral biceps curl in non-exhaustive 6-rep sets using 8-RM with the forearm in supinated, pronated, and neutral positions. The ascending and descending phase of each variation was separately analyzed using the normalized root mean square collected using surface electromyography. During the ascending phase, (i) biceps brachii excitation was greater with the supinated compared to the pronated [+19(7)%, ES: 2.60] and neutral handgrip [+12(9)%, ES: 1.24], (ii) the brachioradialis showed greater excitation with the supinated compared to the pronated [+5(4)%, ES: 1.01] and neutral handgrip [+6(5)%, ES: 1.10], (iii) the anterior deltoid excitation was greater with the pronated and neutral handgrip compared to the supinated condition [+6(3)% and +9(2)%, ES: 2.07 and 3.18, respectively]. During the descending phase, the anterior deltoid showed greater excitation in the pronated compared to the supinated handgrip [+5(4)%, ES: 1.02]. Changing the handgrips when performing biceps curl induces specific variations in biceps brachii and brachioradialis excitation and requires different anterior deltoid interventions for stabilizing the humeral head. Practitioners should consider including different handgrips in the biceps curl routine to vary the neural and mechanical stimuli.

Muscle stretching comprises various modalities that differ in methodological aspects and provide distinct acute and long-term effects on maximal range of motion (ROMmax) and muscle strength. This narrative review aims to: i) describe each stretching modality in detail, including current approaches to quantifying intensity and volume; ii) examine how variations in these parameters influence acute and chronic adaptations in ROMmax and strength; and iii) provide practical guidance by highlighting each method’s advantages, limitations, and effectiveness in achieving flexibility improvements with minimal impact on strength. The reviewed modalities include passive or active static stretching, dynamic or ballistic stretching, and proprioceptive neuromuscular facilitation (PNF). Intensity is commonly measured as stretch-induced discomfort (static), movement velocity or frequency (dynamic/ballistic), or contraction effort (PNF). Volume is quantified as total time at a given %ROMmax (static), number of repetitions (dynamic/ballistic), or contraction-relaxation cycles (PNF). Passive static stretching is effective for increasing ROMmax but may transiently reduce maximal isometric strength, particularly with higher intensities and durations. Dynamic stretching improves ROMmax without affecting strength, while ballistic stretching carries a greater risk of strength impairment. PNF techniques enhance ROMmax across intensity levels, and modified protocols may reduce associated discomfort. Long-term stretching interventions improve flexibility without negatively impacting strength, supporting their strategic use in training. Static stretching may even produce small strength gains when sustained for at least eight weeks. While all modalities acutely enhance ROMmax, chronic effects vary depending on protocol design. Selecting an appropriate stretching technique should align with specific performance goals, particularly in sports requiring extreme ROMmax or when combined with resistance training. Practical considerations such as safety, control, and participant familiarity are essential for effective long-term program implementation.

The current study compared the spatial excitation of the primary muscles during the lat pull-down exercise with the bar passing in front (front-LPD) or behind the neck (back-LPD) using high-density electromyography. Fourteen resistance trained men performed a front-LPD or a back-LPD within a non-fatiguing set with 8-RM as the external load. The muscle excitation centroid of latissimus dorsi, middle trapezius, pectoralis major, biceps brachii, triceps brachii and posterior deltoid muscles were recorded during the ascending and the descending phase. During the descending phase, the front-LPD showed superior excitation of the latissimus dorsi (ES = 0.97) and the pectoralis major (ES = 1.17), while in the ascending phase, the back-LPD exhibited superior excitation of the latissimus dorsi (ES = 0.63), and the front-LPD showed superior excitation of the biceps brachii (ES = 0.41) and the posterior deltoid (ES = 1.77). During the descending phase, the front-LPD showed a more lateral centroid of the latissimus dorsi (ES = 0.60), the biceps brachii (ES = 0.63) and the triceps brachii (ES = 0.98), while the centroid was more medial for the middle trapezius (ES = 0.58). The centroid of the middle trapezius was also more medial in the front-LPD during the ascending phase (ES = 0.85). The pectoralis major centroid was more cranial in the front-LPD for both the descending (ES = 1.58) and the ascending phase (ES = 0.88). The front-LPD appears to provide overall greater excitation in the prime movers. However, distinct spatial excitation patterns were observed, making exercise suitable for the training routine.

Purpose: Cigarette smoking (CS) induces systemic changes that impair cardiorespiratory and muscular function both at rest and during exercise. Although these abnormalities are reported in sedentary, middle-aged smokers (SM) with pulmonary disease, few and controversial studies focused on young, physically active SM at the early stage of smoking history. This study aimed at assessing the effect of CS on cardiorespiratory and metabolic response during an incremental test and the subsequent recovery in young, physically active SM without known lung or cardiovascular disease. Methods: After pulmonary function evaluation, 12 SM (age: 22±2 yr; body mass: 75±8 kg; stature: 1.78±0.06 m; 12±4 cigarette per day for 6±2 yr; mean ± SD) and 12 non-SM (control group; age: 23±1 yr; body mass: 76±8 kg; stature: 1.79±0.08 m) matched for age and exercise habits underwent an exhaustive incremental step test (25 W/2 min) on a cycle ergometer. Pulmonary O ₂ uptake (V̇O ₂ ), expiratory ventilation (V̇ _E ), heart rate ( f _H ) responses and lactate concentration were assessed during the test and subsequent recovery. Results: Despite similar static lung volumes, SM reported lower peak expiratory flow (−23%; P = 0.003) and maximal voluntary ventilation (−10%; P = 0.003). At submaximal exercise, no differences in the cardiorespiratory and metabolic were noted between the two groups. However, SM exhibited ventilatory ( P < 0.01) and lactate thresholds at lower work rates ( P = 0.01). At peak exercise, SM exhibited lower V̇O ₂ (−8%; P = 0.02), mechanical power (−11%; P = 0.02), and V̇ _E (−9%; P = 0.01). During recovery, SM showed longer time constants (τ) in V̇O ₂ (+52%; P = 0.002), V̇ _E (+19%; P = 0.027) and f _H (+21%; P = 0.022) and smaller f _H at 30 s of recovery (HRR30; −31%; P = 0.032). Conclusions: These results are compatible with an early CS-related impairment of the cardiorespiratory and metabolic function even in young individuals with relatively short smoking history.

This study investigated the synergistic difference in the effect of stretching on electromechanical delay (EMD) and its components, using a simultaneous recording of electromyographic, mechanomyographic, and force signals. Twenty-six healthy men underwent plantar flexors passive stretching. Before and after stretching, the electrochemical and mechanical components of the EMD and the relaxation EMD (R-EMD) were calculated in gastrocnemius medialis (GM), lateralis (GL) and soleus (SOL) during a supramaximal motor point stimulation. Additionally, joint passive stiffness was assessed. At baseline, the mechanical components of EMD and R-EMD were longer in GM and GL than SOL (Cohen’s d from 1.78 to 3.67). Stretching decreased joint passive stiffness [-22(8)%, d = -1.96] while overall lengthened the electrochemical and mechanical EMD. The mechanical R-EMD components were affected more in GM [21(2)%] and GL [22(2)%] than SOL [12(1)%], with d ranging from 0.63 to 1.81. Negative correlations between joint passive stiffness with EMD and R-EMD mechanical components were found before and after stretching in all muscles (r from -0.477 to -0.926; P from 0.007 to <0.001). These results suggest that stretching plantar flexors affected GM and GL more than SOL. Future research should calculate EMD and R-EMD to further investigate the mechanical adaptations induced by passive stretching in synergistic muscles.