Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

The main goal of the current study was to compare the effects of volume-equated training frequency on gains in muscle mass and strength. In addition, we aimed to investigate whether the effect of training frequency was affected by the complexity, concerning the degrees of freedom, of an exercise. Participants were randomized to a moderate training frequency group (two weekly sessions) or high training frequency group (four weekly sessions). Twenty-one participants (male: 11, female: 10, age: 25.9 ± 4.0) completed the 9-week whole-body progressive heavy resistance training intervention with moderate (n = 13) or high (n = 8) training frequency. Whole-body and regional changes in lean mass were measured using dual-energy x-ray absorptiometry, while the vastus lateralis thickness was measured by ultrasound. Changes in muscle strength were measured as one repetition maximum for squat, hack squat, bench press, and chest press. No differences between groups were observed for any of the measures of muscle growth or muscle strength. Muscle strength increased to a greater extent in hack squat and chest press than squat and bench press for both moderate (50 and 21% vs. 19 and 14%, respectively) and high-frequency groups (63 and 31% vs. 19 and 16%, respectively), with no differences between groups. These results suggest that training frequency is less decisive when weekly training volume is equated. Further, familiarity with an exercise seems to be of greater importance for strength adaptations than the complexity of the exercise.

The Knowledge and Use of Blood Flow Restriction Therapy in a Sample of Physical Therapists in the United States

Purpose: Blood Flow Restriction Therapy (BFRT) is a rehabilitation technique that seems to elicit hypertrophy gains similar to heavy resistance training. Despite increased popularity of BFRT, the extent it is used in physical therapy (PT) is unknown. The purpose of the study was to examine the knowledge, and utilization, of BFRT by practicing Physical Therapists (PTs). Methods: PTs were recruited to complete an online survey on their knowledge and use of BFRT. Results: From 159 participants, it was found that 88.1% (n=140) of participating PTs had heard of BFRT, with age and gender disparities, though only 38.6% (n=54) reported using BFRT on a patient. There was a significant difference between male and female PTs knowledge (98% vs 81%, p < 0.001) and use (48% vs 24%, p = 0.016) of BFRT. 98% of PTs who reported using BFRT indicated it was beneficial or very beneficial for their patients. Conclusions: There were apparent gaps between PTs knowledge of BFRT and inclusion in practice, though most of these clinicians would be open to consider use of BFRT. Nearly all BFRT practitioners believed it was efficacious and will continue using it. Education and training of PTs could improve utilization of BFRT and, perhaps, ultimately clinical outcomes.

Chronic Sequelae After Muscle Strain Injuries: Influence of Heavy Resistance Training on Functional and Structural Characteristics in a Randomized Controlled Trial

Background: Muscle strain injury leads to a high risk of recurrent injury in sports and can cause long-term symptoms such as weakness and pain. Scar tissue formation after strain injuries has been described, yet what ultrastructural changes might occur in the chronic phase of this injury have not. It is also unknown if persistent symptoms and morphological abnormalities of the tissue can be mitigated by strength training. Purpose: To investigate if heavy resistance training improves symptoms and structural abnormalities after strain injuries. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 30 participants with long-term weakness and/or pain after a strain injury of the thigh or calf muscles were randomized to eccentric heavy resistance training of the injured region or control exercises of the back and abdominal muscle. Isokinetic (hamstring) or isometric (calf) muscle strength was determined, muscle cross-sectional area measured, and pain and function evaluated. Scar tissue ultrastructure was determined from biopsy specimens taken from the injured area before and after the training intervention. Results: Heavy resistance training over 3 months improved pain and function, normalized muscle strength deficits, and increased muscle cross-sectional area in the previously injured region. No systematic effect of training was found upon pathologic infiltration of fat and blood vessels into the previously injured area. Control exercises had no effect on strength, cross-sectional area, or scar tissue but a positive effect on patient-related outcome measures, such as pain and functional scores. Conclusion: Short-term strength training can improve sequelae symptoms and optimize muscle function even many years after a strain injury, but it does not seem to influence the overall structural abnormalities of the area with scar tissue. Registration: NCT02152098 (ClinicalTrials.gov identifier).

Left Ventricular Dimensions and Diastolic Function Are Different in Throwers, Endurance Athletes, and Sprinters From the World Masters Athletics Championships

There is controversy whether a lifetime of heavy resistance training, providing pressure-overload, is harmful for left ventricular function. We compared left ventricular dimensions and function in elite Masters athletes involved in throwing events (requiring strength; n = 21, seven females, 60 ± 14 years) to those involved in endurance events (n = 65, 25 females, 59 ± 10 years) and sprinting (n = 68, 21 females, 57 ± 13 years) at the 2018 World Masters Athletic Championships. Left ventricular dimensions and function were assessed with B-mode ultrasound and Doppler. The ratio of left ventricular early diastolic peak filling velocity to peak velocity during atrial contraction (E/A) across the mitral valve and the ratio of E to velocity of the E-wave (E’) across the lateral and septal mitral annulus (E/E’) were used as indexes of left ventricular diastolic function. Intra-ventricular septal wall thickness was greater in throwers compared to sprinters (11.9 ± 2.2 vs. 10.3 ± 2.3 mm; p = 0.01). Left ventricular end diastolic diameter/body surface area was higher in endurance athletes and sprinters vs. throwers (25.2 ± 3.0, 24.3 ± 3.1, and 22.0 ± 3.1 mm/m2, respectively, p &lt; 0.01). The E/A was higher in endurance athletes and sprinters vs. throwers (1.35 ± 0.40, 1.37 ± 0.43, and 1.05 ± 0.41, respectively; p &lt; 0.01). The E/E’ was lower in endurance athletes and sprinters vs. throwers (6.9 ± 1.8, 6.6 ± 1.9, and 8.1 ± 1.9, respectively, p &lt; 0.05). Compared to age-matched historical controls (n &gt; 1,000; E/A = 1.06; E/E’ = 7.5), left ventricular diastolic function was not different in throwers, but superior in endurance athletes and sprinters (p &lt; 0.01). Masters throwers have altered left ventricular dimensions and function vs. other athletes, but a lifetime of heavy resistance training does not appear to alter left ventricular function compared to age-matched controls.

PROTEIN SUPPLEMENTATION DOES NOT RESCUE MUSCLE MASS AND FUNCTION–HEAVY RESISTANCE TRAINING IS REQUIRED

The requirement of an enhanced dietary protein intake to counteract the age-related loss of muscle mass is still debated. Further, the dinner meal generally contains the majority of protein and energy and since, the muscle of older adults responds less to protein intake than that of younger adults it is hypothesized that older adults would benefit from taking more protein in at other meals. The aim of this study was to investigate whether the provision of protein supplements for breakfast and lunch meals over the course of a year would make healthy, older, home-dwelling adults (N=136) take in more protein and whether that then would affect their muscle mass (primary outcome) and a number of metabolic health parameters, muscle strength parameters and functional capabilities. More than 77% ingested more than 75% of the provided supplements, irrespective of supplementation type (isocaloric carbohydrate; collagen hydrolysate low quality protein: whey hydrolysate high quality protein). Providing supplementation for a year among older adults makes them comply very well. However, provision of extra protein has no impact on the muscle mass or strength or on the functional parameters. Further, we studied the impact of adding resistance training on top of WHEY protein supplementation and found that heavy more than light-load resistance training affects fat-free mass and maximal-voluntary contraction. Daily protein intake can be enhanced by supplementation but do not impact muscle mass and function over the course of a year, where heavy resistance training on top benefits, but to a lesser than expected degree.