Respiratory muscle training in non-athletes and athletes with spinal cord injury: A systematic review of the effects on pulmonary function, respiratory muscle strength and endurance, and cardiorespiratory fitness based on the FITT principle of exercise prescription.

BACKGROUND: Respiratory muscle training (RMT) has been recommended to mitigate impacts of spinal cord injuries (SCI), but the optimal dosage in terms of the frequency, intensity, time, and type (FITT principle) to promote health in SCI individuals remains unclear. OBJECTIVE: To discuss research related to the effects of RMT on pulmonary function, respiratory muscle strength and cardiorespiratory fitness in athletes and non-athletes with SCI, presenting the FITT principle. METHODS: We performed a systematic review. PubMed, Lilacs, Scopus, Web of Science, PEDro, SciELO and Cochrane databases were searched between 1989 and August 2018. Participants were athletes and non-athletes with SCI. RESULTS: 4,354 studies were found, of which only 17 met the eligibility criteria. Results indicated that RMT is associated with beneficial changes in pulmonary function and respiratory muscle strength and endurance among athletes and non-athletes, whereas no effect was reported for maximal oxygen uptake. It was not possible to establish an optimal RMT dose from the FITT principle, but combined inspiratory/expiratory muscle training seems to promote greater respiratory changes than isolated IMT or EMT. CONCLUSION: The use of RMT elicits benefits in ventilatory variables of athletes and non-athletes with SCI. However, it remains unclear which RMT type and protocol should be used to maximize benefits.

Maximal repetition performance, rating of perceived exertion, and muscle fatigue during paired set training performed with different rest intervals.

BACKGROUND/OBJECTIVE: The purpose of this study was to examine rest interval length between agonist-antagonist paired set training (PS) on maximal repetition performance, rating of perceived exertion, and neuromuscular fatigue. METHODS: Fourteen trained men (age, 24.2 ± 1.1 years; height, 175 ± 5.5 cm; body mass, 76.6 ± 7.0 kg) performed two experimental protocols in random order with 2 minutes (P2) or 4 minutes (P4) between agonist-antagonist PS, which consisted of a bench press set followed immediately by a seated row set with 8-repetition maximum loads, respectively. A total of three PS were performed for each rest interval protocol. The total repetitions performed and the rating of perceived exertion were recorded for each exercise set within each rest interval protocol. Electromyography signals were recorded for the posterior deltoid, biceps brachii, pectoralis major, and triceps brachii muscles during the SR exercise. The electromyography signals were then used to calculate a fatigue index for each rest interval protocol. RESULTS: No significant differences were identified in the total repetitions completed between rest interval protocols for the bench press (P2 = 22.9 ± 1.3 and P4 = 22.6 ± 0.8) and seated row (P2 = 25.4 ± 1.7 and P4 = 25.1 ± 1.3). However, a significantly higher fatigue index was found for all muscles under the P2 versus the P4 protocol. CONCLUSION: When performing agonist-antagonist PS, prescribing a shorter rest interval between PS may induce higher levels of fatigue, albeit with similar total repetitions versus a longer rest interval.

Basal and resting metabolic rates of physically disabled adult subjects: a systematic review of controlled cross-sectional studies.

AIM: To systematically review studies that investigated the basal metabolic rate (BMR) and resting metabolic rate (RMR) of physically disabled adult subjects. METHODS: The studies were identified via MedLine, Science Direct, Science Search, Scientific Electronic Library Online, Wiley, Latin American and Caribbean Health Sciences Literature, Cochrane, Indice Bibliográfico Espanõl de Ciencias de la Salud, Scopus, ProQuest Dissertations & Theses Database and System for Information on Grey Literature in Europe. No restriction on publication date was imposed. RESULTS: Data from 6 studies were included. The results showed that physically disabled adult subjects have a lower BMR and/or RMR compared to nondisabled subjects. However, the difference between the groups disappeared when the BMR and RMR were adjusted for fat-free mass. Due to the small number of studies on this subject and the limited types of physical disabilities evaluated in the literature, we could not make a definitive conclusion. CONCLUSIONS: Disabled individuals seem to have a lower absolute BMR and/or RMR than able-bodied adults; however, this difference was not present or else it disappeared in half of the studies, after adjusting for body mass and/or fat-free mass.

Quality of life, muscle strength, and fatigue perception in patients on suppressive therapy with levothyroxine for differentiated thyroid carcinoma.

OBJECTIVES: The aim of this study was to evaluate the fatigue perception, the muscle function, and the health-related quality of life (QoL) in subclinical hyperthyroidism (SCH) induced by levothyroxine in the treatment of differentiated thyroid carcinoma, in comparison with a group of euthyroid (EU) subjects. PATIENTS AND METHODS: A cross-sectional study with 38 SCH individuals and 54 EU subjects was performed. They were submitted to Short Form-36 and Chalder questionnaires to evaluate QoL and fatigue, respectively. The tests performed to evaluate muscle function of upper and lower limbs were: maximum quadriceps isometric strength (QS); quadriceps fatigue resistance (T50% QS), QS at 30 seconds (QS30s); quadriceps functional capacity (QFC); maximum isometric handgrip strength (HS); fatigue handgrip resistance (T50% HS), HS at 30 seconds (HS30s); and functional capacity of the shoulder. RESULTS AND CONCLUSIONS: The SCH patients had worse muscle function, regarding HS (25.19 ± 7.00 vs. 30.45 ± 9.98 kgf in EU, P = 0.009) and functional capacity of the shoulder (41.28 ± 48.36 vs. 56.68 ± 37.44 s in EU, P = 0.004). The self-perception of fatigue by Chalder questionnaire (23.91 ± 5.39 vs. 29.77 ± 7.03, P = 0.000) and the QoL in terms of functional capacity (70.20 ± 21.57 vs. 56.25 ± 28.79, P = 0.025), physical aspects (71.42 ± 36.44 vs. 45.83 ± 42.88, P = 0.004), pain (62.48 ± 22.20 vs. 50.05 ± 24.80, P = 0.035), and emotional aspects (70.74 ± 38.26 vs. 46.29 ± 44.56, P = 0.008) were also worse in SCH. In conclusion, the SCH was associated with alterations in the QoL, reduction in the muscle function of upper limbs, and higher degree of fatigue.

Exercise order interacts with rest interval during upper-body resistance exercise.

The purpose of this study was to compare repetition performance when resting 1 minute vs. 3 minutes between sets and exercises for an upper-body workout performed in 2 different sequences. Sixteen recreationally trained men completed 4 experimental resistance exercise sessions. All sessions consisted of 3 sets with an 8-repetition maximum load for 6 upper-body exercises. Two different exercise sequences (i.e., A or B) were performed with either 1- or 3-minute rest between sets and exercises, respectively. For sequence A1 (SEQA1) and sequence A3 (SEQA3), resistance exercises were performed in the following order: lat pull-down with a wide grip (LPD-WG), lat pull-down with a close grip (LPD-CG), machine seated row (SR-M), barbell row lying on a bench (BR-B), dumbbell seated arm curl (SAC-DB), and machine seated arm curl (SAC-M). Conversely, for sequence B1 (SEQB1) and sequence B3 (SEQB3), the exercises were performed in the opposite order. The results demonstrated that the effect of exercise order was stronger than the effect of rest interval length for LPD-WG (SEQA3>SEQA1>SEQB3>SEQB1) and SAC-M (SEQB3>SEQB1>SEQA3>SEQA1), whereas the effect of rest interval length was stronger than the effect of exercise order for LPD-CG, SR-M, SAC-DB (SEQA3=SEQB3>SEQA1=SEQB1), and BR-B (SEQB3>SEQA3=SEQB1>SEQA1). These results suggest that upper-body exercises involving similar muscle groups and neural recruitment patterns are negatively affected in terms of repetition performance when performed at the end vs. the beginning of a session, and the reduction in repetition performance is greater when using 1-minute vs. 3-minute rest interval between sets.