Muscular Adaptations Between Very Low Load Resistance Training With Pulsed Direct Current Stimulation (Neubie) and Traditional High Load Training.

OBJECTIVES: This study compared muscle growth in response to very low load resistance training with direct pulsed current (DPC) stimulation and traditional high load training. METHODS: Twenty-six resistance trained individuals had each leg assigned to one of two unilateral knee extension protocols: 1) 4 sets of 20 repetitions at ~10% one-repetition maximum (1RM) and inter-set rest periods of 30 s (DPC) and 2) 4 sets to muscular failure at ~70% 1RM (TRAD). Muscle thickness (MTH), 1RM strength, and local muscular endurance (LME) were measured before and after 8-weeks of training. An alpha level of 0.05 was used for all comparisons. RESULTS: MTH increased similarly between TRAD and DPC at the 50% (0.24 cm, 95%CI: 0.11-0.36), and the 60% anterior sites (0.25 cm, 95%CI: 0.10-.040), as well as the lateral (0.25 cm, 95%CI: 0.10-.040) and medial sites (0.21 cm, 95%CI: 0.10-0.31), but was greater for TRAD at the 40% anterior site (0.3 cm, 95%CI: 0.16-0.43). Changes in 1RM were greater for TRAD (10.2 kg, 95%CI: 5.8-14.4). LME increased similarly between protocols (5 repetitions, 95%CI: 3-7). CONCLUSIONS: The current data suggest that very low load knee extension resistance training with DPC could be a viable training strategy for promoting skeletal muscle growth and local muscular endurance.

Tennis Specialization and Consequence of Injury/Illness Following Retirement.

(1) Background: There is a lack of literature that examines the impact of early vs. late sport specialization on quality of life after retirement from tennis. Thus, the purpose of this study was to examine the relationship between early specialization in the sport of tennis and health outcomes after retirement from collegiate/professional sport; (2) Methods: Participants were recruited through social media posts, newsletters, and contacts with tennis organizations. Basic demographic and injury information was collected from 157 former tennis players, along with the age of tennis specialization and two questionnaires: the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC), and the CDC HRQOL-14 "Healthy Days Measure" Questionnaire (HRQOL); (3) Results: Significant differences (F1,117 = 5.160, p < 0.025) in the specialization age between the low (11.9 ± 4.5 y) and high (9.8 ± 4.1 y) OSTRC groups were found after covarying for the current age. No difference (F1,72 = 0.676, p < 0.414) was shown among the high (10.9 ± 4.4 y) and low (11.28 ± 4.6 y) HRQOL groups for the specialization age after covarying for the current age. A weak negative correlation was identified between the OSTRC score and specialization age (r = -0.233, p = 0.008), while no significant changes were shown between the specialization age and HRQOL score (r = -0.021, p = 0.857), or between the OSTRC and HRQOL scores (r = 0.146, p = 0.208); (4) Conclusions: Retired tennis players with low injury/illness severity scores specialized in tennis later than those with high injury/illness severity scores, while no differences in the specialization age were noted when the sample was separated into HRQOL groups.

Carbohydrate-Protein drink is effective for restoring endurance capacity in masters class athletes after a two-Hour recovery.

BACKGROUND: Carbohydrate (CHO) and carbohydrate-protein co-ingestion (CHO-P) have been shown to be equally effective for enhancing glycogen resynthesis and subsequent same-day performance when CHO intake is suboptimal (≤0.8 g/kg). Few studies have specifically examined the effect of isocaloric CHO vs CHO-P consumption on subsequent high-intensity aerobic performance with limited time to recover (≤2 hours) in masters class endurance athletes. METHODS: This was a randomized, double-blind between-subject design. Twenty-two male masters class endurance athletes (age 49.1 ± 6.9 years; height 175.8 ± 4.8 cm; body mass 80.7 ± 8.6 kg; body fat (%) 19.1 ± 5.8; VO2peak 48.6 ± 6.7 ml·kg·min-1) were assigned to consume one of three beverages during a 2-hour recovery period: Placebo (PLA; electrolytes and water), CHO (1.2 g/kg bm), or CHO-P (0.8 g/kg bm CHO + 0.4 g/kg bm PRO). All beverages were standardized to one liter (~32 oz.) of total fluid volume regardless of the treatment group. During Visit #1, participants completed graded exercise testing on a cycle ergometer to determine VO2peak and peak power output (PPO, watts). Visit #2 consisted of familiarization with the high-intensity protocol including 5 × 4 min intervals at 70-80% of PPO with 2 min of active recovery at 50 W, followed by a time to exhaustion (TTE) test at 90% PPO. During Visit#3, the same high-intensity interval protocol with TTE was conducted pre-and post-beverage consumption. RESULTS: A one-way ANCOVA indicated a significant difference among the group means for the posttest TTE (F2,18 = 6.702, p = .007, ƞ2 = .427) values after adjusting for the pretest differences. TTE performance in the second exercise bout improved for the CHO (295.48 ± 24.90) and CHO-P (255.08 ± 25.07 sec) groups. The water and electrolyte solution was not effective in restoring TTE performance in the PLA group (171.13 ± 23.71 sec). CONCLUSIONS: Both CHO and CHO-P effectively promoted an increase in TTE performance with limited time to recover in this sample of masters class endurance athletes. Water and electrolytes alone were not effective for restoring endurance capacity during the second bout of exhaustive exercise.

Injuries and Strength Training Practices in Collegiate Tennis.

Strength and conditioning practices may influence injury rates in the sport of tennis. Methods: Coaches reported the number injuries over the past year. Coaches were also surveyed on whether their training program included training related to upper-body or lower-body strength, power, muscle growth, and eccentric exercise. Separate regression analyses were run in the upper and lower body to examine the relationship between injuries and participation in training focused on strength, power, growth, and maximal eccentric exercise. A total of 111 coaches were surveyed. The most frequent injuries observed were ankle sprains (144 injures), followed by paraspinal muscle strains (126 injuries). When pooled, there were a total of 355 lower-body and 260 upper-body injuries. Strength and conditioning practices explained 9.9% of the variance of injury rates in the upper body (R2 = 0.099). The only significant predictor of upper-body injury was participation in upper-body muscle growth training (ß = 1.613, p = 0.013). In addition, training practices explained 11.1% of the variance of injury in the lower body (R2 = 0.111). Coaches value injury prevention exercise, sports-specific training and flexibility and mobility training the most, with muscle growth and maximal power ranked lowest. Additionally, the most frequent injuries observed in collegiate tennis players were ankle sprains (144 injures), followed by paraspinal muscle strains (126 injuries).

The acute muscular response following a novel form of pulsed direct current stimulation (Neubie) or traditional resistance exercise.

OBJECTIVES: To examine changes in muscle thickness (MT), soreness (SOR), and isometric torque (ISO) following exercise with pulsed direct current (Neubie) or traditional high-load (TRAD) exercise. METHODS: Thirty-two participants had SOR, MT, and ISO measured before, immediately after, and 24 and 48h following TRAD and Neubie. Rating of perceived exertion (RPE) and discomfort were also measured. Results are displayed as means(SD). RESULTS: For MT, there was a condition x time interaction (p<0.001). For Neubie, MT increased pre [3.7(0.7)cm] to post [3.9(0.8) cm, p<0.001] and remained elevated at 24h. For TRAD, MT increased pre [3.7(0.6)cm] to post [4.0 (0.7)cm, p<0.001] and remained up to 48h. Greater values were observed for TRAD post-exercise. For ISO, both conditions decreased up to 48h. TRAD demonstrated a greater change post exercise (p<0.001). For SOR, both conditions increased up to 48h. Neubie demonstrated greater SOR at 48h (p=0.007). RPE was higher for all sets in TRAD [Mean across sets=16.0(1.9) vs. 13.5(2), p<0.001]. Discomfort was higher in all sets for Neubie [Mean across sets=5.8(1.5)vs. 4.5(2.0), p<0.05]. CONCLUSIONS: Both conditions showed increased SOR, and decreased ISO for up to 48h, with MT increased for up to 24h. MT remained elevated in TRAD at 48h. Neubie training might be effective for individuals who are looking to experience lower RPE responses during exercise.

Muscle growth adaptations to high-load training and low-load training with blood flow restriction in calf muscles.

PURPOSE: To compare muscle growth adaptations between traditional high-load training and low-load training with blood flow restriction (BFR) in the calf muscles over 6 weeks. METHODS: 27 trained individuals performed calf exercise in both legs for 6 weeks. Each leg was randomly assigned to one of the two conditions: (1) Traditional (70% of 1RM) training (TRAD); and (2) Low-load (30% of 1RM) training with BFR. In addition, subjects performed standing calf raises with or without BFR. Measures were taken pre- and post-intervention. RESULTS: For the posterior muscle site, there was no condition (BFR vs. TRAD) × time (pre vs. post) interaction (p = 0.15). In addition, there was no main effect for condition (p = 0.83) or time (p = 0.20). For the lateral muscle site, there was no condition × time interaction (p = 0.47). In addition, there was no main effect for condition (p = 0.10) or time (p = 0.57). For the medial muscle site, there was no condition × time interaction (p = 0.60). In addition, there was no main effect for condition (p = 0.44) or time (p = 0.72). For RPE, there was no condition × time interaction. However, there was a main effect for condition (p < 0.05) with BFR having higher RPE. For discomfort, there was no condition × time interaction. However, there was a main effect for condition (p < 0.001) with the BFR condition displaying higher discomfort. CONCLUSION: No muscle growth was detected in the calf musculature. BFR was not more effective at eliciting muscle hypertrophy compared to traditional training. However, it was accompanied with higher exertion and discomfort.

Examination of Changes in Echo Intensity Following Resistance Exercise among Various Regions of Interest.

AIM: Within the resistance exercise literature, echo intensity (EI) is often quantified using different regions of interest (ROI). PURPOSE: To compare changes in the EI of images of the biceps muscle using different ROI immediately following exercise as well as 24 and 48 h following exercise. METHODS: Twenty seven non-resistance trained individuals visited the laboratory 4 times. One arm was assigned to the experimental condition, and the other was a non-exercise control. During visit 1, paperwork and strength were measured. During visit, 2 participant's muscles were imaged before performing biceps curls. Additional muscle images were taken immediately after exercise, as well as 24 and 48 h post. EI was measured using three different ROI: 1) Trace around the entire muscle; 2) Small box placed in the middle of the muscle (2 × 2cm); and 3) Maximal rectangular box. Results are displayed as means (95%CI). RESULTS: There was no condition (experimental vs. control) x time (pre, post, 24h and 48h) x box size (small, large, full trace) interaction (p = 0·592). However, there was a main effect for box size (p < 0·001). EI values were higher with the small box [28·2 (23·3, 33·1) AU] compared to the large box [26·8 (22·3, 31·2) AU, p = 0·016] and compared to the full trace [24·2 (20·3, 28·0) AU p < 0·001)]. In addition, EI values were higher with the large box compared to the full trace technique (p = 0·001). CONCLUSION: Similar changes in EI are detected when using different commonly used ROI for analysing EI. However, when larger ROI are examined, EI values appear to be lower.

Is there Evidence for the Suggestion that Fatigue Accumulates Following Resistance Exercise?

It has been suggested that improper post-exercise recovery or improper sequence of training may result in an 'accumulation' of fatigue. Despite this suggestion, there is a lack of clarity regarding which physiological mechanisms may be proposed to contribute to fatigue accumulation. The present paper explores the time course of the changes in various fatigue-related measures in order to understand how they may accumulate or lessen over time following an exercise bout or in the context of an exercise program. Regarding peripheral fatigue, the depletion of energy substrates and accumulation of metabolic byproducts has been demonstrated to occur following an acute bout of resistance training; however, peripheral accumulation and depletion appear unlikely candidates to accumulate over time. A number of mechanisms may contribute to the development of central fatigue, postulating the need for prolonged periods of recovery; however, a time course is difficult to determine and is dependent on which measurement is examined. In addition, it has not been demonstrated that central fatigue measures accumulate over time. A potential candidate that may be interpreted as accumulated fatigue is muscle damage, which shares similar characteristics (i.e., prolonged strength loss). Due to the delayed appearance of muscle damage, it may be interpreted as accumulated fatigue. Overall, evidence for the presence of fatigue accumulation with resistance training is equivocal, making it difficult to draw the conclusion that fatigue accumulates. Considerable work remains as to whether fatigue can accumulate over time. Future studies are warranted to elucidate potential mechanisms underlying the concept of fatigue accumulation.

Do exercise-induced increases in muscle size contribute to strength in resistance-trained individuals?

AIM: Previous work in non-resistance-trained individuals has found that an increase in muscle size has no additive effect on changes in strength. However, it is thought that muscle growth is of increased importance for resistance-trained individuals. PURPOSE: Experiment 1: To examine changes in muscle thickness (MT) and one repetition maximum (1RM) strength following 8 weeks of bi-weekly 1RM practice or traditional training. Experiment 2: To determine whether increasing muscle size increases strength potential when followed by 4 weeks of 1RM training. METHODS: Participants performed biceps curls for 8 weeks (Experiment 1). One arm performed 4 sets of as many repetitions as possible with approximately 70% of 1RM (TRAD), and the other arm performed a single 1RM. For experiment 2, both arms trained for muscle size and strength. RESULTS: Experiment 1 (n = 25): for MT, the posterior probabilities favoured the hypothesis that MT changed more in the TRAD condition [mean difference: 50% site 0.15 (-0.09, 0.21) cm; 60% site 0.14 (0.06, 0.23) cm; 70% site 0.17 (0.10, 0.23) cm]. For 1RM strength, each condition changed equivalently. Experiment 2 (n = 18): for MT, the posterior probabilities favoured the hypothesis that MT changed similarly between conditions following a 4-week strength phase. For changes in 1RM strength, the evidence favoured neither hypothesis (i.e. null vs. alternative). Of note, the mean difference between conditions was small [0.72 (4.3) kg]. CONCLUSIONS: 1RM training produces similar increases in strength as traditional training. Experiment 2 suggests that increases in muscle mass may not increase the 'potential' for strength gain.

Periodization: Variation in the Definition and Discrepancies in Study Design.

Over the past several decades, periodization has been widely accepted as the gold standard of training theory. Within the literature, there are numerous definitions for periodization, which makes it difficult to study. When examining the proposed definitions and related studies on periodization, problems arise in the following domains: (1) periodization has been proposed to serve as the macro-management of the training process concerning the annual plan, yet research on long-term effects is scarce; (2) periodization and programming are being used interchangeably in research; and (3) training is not periodized alongside other stressors such as sport (i.e., only resistance training is being performed without the inclusion of sport). Overall, the state of the literature suggests that the inability to define periodization makes the statement of its superiority difficult to experimentally test. This paper discusses the proposed definitions of periodization and the study designs which have been employed to examine the concept.

An examination of changes in muscle thickness, isometric strength and body water throughout the menstrual cycle.

PURPOSE: The purpose of this study was to examine the changes in muscle size and strength throughout the menstrual cycle in females and to compare these values to a control group of time-matched males. METHODS: 12 males and 16 females visited the laboratory on four occasions. Measures of muscle thickness (MTH), isometric strength and body water were taken during the menstrual phase, ovulation phase and luteal phase of the menstrual cycle. Males scheduled their visits based on a mock menstrual cycle. In addition, participants were asked to complete 4 sets of biceps curls to volitional failure in one arm to examine swelling during each visit. RESULTS: For MTH there was no interaction (p = .73); however, there was a main effect for sex with males having higher MTH values compared to females [4.07 (0.67) versus. 2.73 (0.42) cm, (p < .001)] at all time points. For changes in MTH (swelling) there was no interaction (p = .28). However, there was a main effect for sex, with males demonstrating greater changes in MTH compared to females [0.53(0.11) versus. 0.40 (0.10) cm, (p < .001)]. Similarly, for total body water, there was no interaction (p = .66). However, males had greater total body water compared to females [49.6 (6.8) versus. 32.3(3.9) kg, p < .001)] at all time points. Finally, for isometric strength, there was no interaction (p = .23). However, there was a main effect for sex. Males had higher isometric strength values compared to females [285 (42) versus. 156(36) N (p < .001)]. CONCLUSIONS: Phase of the menstrual cycle does not appear to influence MTH, isometric strength or total body water.

An examination of changes in skeletal muscle thickness, echo intensity, strength and soreness following resistance exercise.

It is suggested that changes in echo intensity (EI) measured through ultrasound can detect muscle swelling. However, changes in EI have never been examined relative to a non-exercise control following naïve exposure to exercise. PURPOSE: Examine the changes in muscle thickness (MT), EI and isometric strength (ISO) before, immediately after, and 24, and 48 hr following biceps curls. METHODS: Twenty-seven non-resistance-trained individuals visited the laboratory four times. During visit 1, paperwork was completed and strength was measured. During visit 2, MT and ISO were measured before four sets of curls. Additional measures were taken immediately after exercise, as well as 24 and 48 hr post. Results are displayed as means (SD). RESULTS: For MT, there was an interaction (p < .001). For the experimental condition, MT increased from pre [2.88(0.64) cm] to post [3.27(0.67) cm] and remained elevated 48 hr post. There were no changes for MT in the control arm. In the experimental arm, EI increased from pre [22.9(9.6) AU] to post [29.1(12.3) AU] exercise and returned to baseline by 24 hr. For the control condition, EI was different between pre [24.8(10.2) AU] and 48 hr [21.5(10.7) AU]. The change in EI in the experimental condition was greater than the control condition immediately post (p = .039) and at 48 hr (p = .016). For ISO, there was an interaction (p < .001). In the experimental condition, ISO decreased from pre [40.6(14.7) Nm)] to post [24.8(9.4) Nm] and remained depressed. CONCLUSIONS: Exercise produced a swelling response, which was elevated 48 hr post. Despite a sustained increase in MT, EI was only elevated immediately post exercise.