Stuart M. Phillips’s research while affiliated with McMaster University and other places

It has been hypothesised that skeletal muscle protein turnover is affected by menstrual cycle phase with a more anabolic environment during the follicular vs. the luteal phase. We assessed the influence of menstrual cycle phase on muscle protein synthesis and myofibrillar protein breakdown in response to 6 days of controlled resistance exercise in young females during peak oestrogen and peak progesterone, using stable isotopes, unbiased metabolomics and muscle biopsies. We used comprehensive menstrual cycle phase‐detection methods, including cycle tracking, blood samples and urinary test kits, to classify menstrual phases. Participants (n = 12) completed two 6 day study phases in a randomised order: late follicular phase and mid‐luteal phase. Participants performed unilateral resistance exercise in each menstrual cycle phase, exercising the contralateral leg in each phase in a counterbalanced manner. Follicular phase myofibrillar protein synthesis (MPS) rates were 1.33 ± 0.27% h⁻¹ in the control leg and 1.52 ± 0.27% h⁻¹ in the exercise leg. Luteal phase MPS was 1.28 ± 0.27% h⁻¹ in the control leg and 1.46 ± 0.25% h⁻¹ in the exercise leg. We observed a significant effect of exercise (P < 0.001) but no effect of cycle phase or interaction. There was no significant effect of menstrual cycle phase on whole‐body myofibrillar protein breakdown (P = 0.24). Using unbiased metabolomics, we observed no notable phase‐specific changes in circulating blood metabolites associated with any particular menstrual cycle phase. Fluctuations in endogenous ovarian hormones influenced neither MPS, nor MPB in response to resistance exercise. Skeletal muscle is not more anabolically responsive to resistance exercise in a particular menstrual cycle phase. image Key points It has been hypothesised that the follicular (peak oestrogen) vs. the luteal (peak progesterone) phase of the menstrual cycle is more advantageous for skeletal muscle anabolism in response to resistance exercise. Using best practice methods to assess menstrual cycle status, we measured integrated (over 6 days) muscle protein synthesis (MPS) and myofibrillar protein breakdown (MPB) following resistance exercise in females (n = 12) in their follicular and luteal phases. We observed the expected differences in oestrogen and progesterone concentrations that confirmed our participants’ menstrual cycle phase; however, there were no notable metabolic pathway differences, as measured using metabolomics, between cycle phases. We observed that resistance exercise stimulated MPS, but there was no effect of menstrual cycle phase on either resting or exercise‐stimulated MPS or MPB. Our data show no greater anabolic effect of resistance exercise in the follicular vs. the luteal phase of the menstrual cycle.

This article provides a recap of the 10 Questions/10 Experts session at the 2024 American College of Sports Medicine Annual Meeting. Each of the speakers considered the validity of common “myths,” while providing evidence-based opinions to support, or, bust, myths addressing the following questions: (1) Would 100 g/hr of carbohydrate be advisable for the Olympic Cycling Road race? (2) Is there an advantage in the marathon of ingesting bicarbonate as a hydrogel product? (3) Can genotyping be used to individualize caffeine supplementation in football? (4) Should low fluid consumers drink more to improve 1,500-m track performance? (5) Do urinary markers of dehydration predict poor basketball performance? (6) Do placebo effects influence 10-km track performance? (7) Should combat athletes make weight using glucagon-like peptide-1 receptor agonists? (8) Would crushed ice ingestion help tennis umpires make better decisions in the heat? (9) Are collagen supplements useful to reduce tendon and ligament injuries in volleyball? and (10) Should female athletes plan their training and diet according to their menstrual cycle? This article describes the content of each of the presentations including the most important outcomes and conclusions drawn by the presenters.

Background Aging is the primary risk factor for sarcopenia and mobility limitations. Exercise reduces these risks, but older adults have low levels of participation in physical activity and exercise. We investigated the preliminary effectiveness of a live, online exercise program on community-dwelling older adults’ physical activity levels. Methods A mixed-method pilot randomized controlled trial was conducted according to CONSORT 2010 statement: extension for pilot and feasibility trials. Sedentary older adults (65–80 years) were randomly assigned to the online exercise intervention (ACTIVE) or a waitlist control (CON) group. Outcomes were measured pre-randomization and following the 8-week intervention for ACTIVE and CON and two months following the end of the intervention for the ACTIVE group. Outcomes included habitual physical activity levels, depression, anxiety, loneliness, life-space mobility, nutrition risk, and feasibility. All participants were invited to participate post-intervention in individual semi-structured qualitative interviews. Reporting of the qualitative research followed the checklist for the Consolidated Criteria for Reporting research. Results Seventeen older adults (71% women) were allocated to ACTIVE group, while 15 were allocated to CON group (87% women). Following the intervention, participants in the ACTIVE group reported reduced symptoms of depression (ACTIVE: pre = 4.2 ± 2.5; post = 2.2 ± 1.9; CON: pre = 3.5 ± 2.1, post = 3.5 ± 2.1; p <0.001) and improved life-space mobility (ACTIVE: pre = 62.4 ± 14.7; post = 71.8 ± 16.0; CON: pre = 65.1 ± 19.0, post = 63.6 ± 22.0; p = 0.003) compared to waitlist control participants. The ACTIVE group had good adherence (97%) and acceptability (98%). Twenty-two participants participated in qualitative interviews. Five themes were identified, including (1) Feasibility of the online exercise program; (2) Perceived health benefits and improvements; (3) Registered Kinesiologists and Physiotherapists contributed to perceived safety; (4) Social connectivity associated with synchronous/live delivery; and (5) Growing old gracefully and preventing disability. Conclusions Our online exercise program was acceptable to older adults, had good adherence, reduced depression, and increased life space. Participants reported improved functional and mental health benefits. Further research is warranted to expand on these findings. Trial registration NCT04627493; 13/11/2020.

Background: Older adults live with chronic conditions worldwide. The aim of this systematic review was to determine the effectiveness of physiotherapist-led (PT-led) tele-rehabilitation on various health outcomes. Methods: Six databases were searched. Eligible studies were randomized controlled trials that included older adults (≥65 years) who had ≥1 chronic condition, and evaluated tele-rehabilitation (e.g., video, telephone) that was PT-led or overseen. Screening and data extraction were performed in duplicate. Meta-analyses were performed where appropriate. Cochrane's Risk of Bias 2.0 tool was used. Results: Fifteen studies were included. A meta-analysis of studies of knee osteoarthritis demonstrated that tele-rehabilitation is more effective than usual care for functional mobility (MD= -2.72, 95% CI= -3.56, -1.88, p < 0.001), quadriceps strength (MD= 15.54, 95% CI= 10.14, 20.95, p < 0.001), pain (MD= -1.2, 95% CI= -2.09, -0.39, p = 0.004) and physical function (MD= -5.95, 95% CI= -8.32, -3.58, p < 0.001). No clear differences were found between tele-rehabilitation and usual care or comparator interventions for outcomes related to physical activity level, gait speed, mental health, and quality of life. Conclusions: PT-led tele-rehabilitation appears to be comparable to traditional methods at improving outcomes in older adults with various chronic conditions. However, high-quality trials are needed so future conclusions on the effectiveness of tele-rehabilitation can be made. Unlabelled: CRD42023428048.

Introduction Skeletal muscle satellite cells (SC) contribute to the adaptive process of resistance exercise training (RET) and may be influenced by nutritional supplementation. However, little research exists on the impact of multi-ingredient supplementation on the SC response to RET. Purpose We tested the effect of a multi-ingredient supplement (MIS) including whey protein, creatine, leucine, calcium citrate, and vitamin D on SC content and activity as well as myonuclear accretion, SC and myonuclear domain compared with a collagen control (COL) throughout a 10-wk RET program. Methods Twenty-six participants underwent a 10-wk linear RET program while consuming either the MIS or COL supplement twice daily. Muscle biopsies were taken from the vastus lateralis at baseline and 48 h after a bout of damaging exercise, before and after RET. Muscle tissue was analyzed for SC and myonuclear content, domain, acute SC activation, and fiber cross-sectional area (fCSA). Results MIS resulted in a greater increase in type II fCSA following 10 wk of RET (effect size (ES) = 0.89) but not myonuclear accretion or SC content. Change in myonuclei per fiber was positively correlated with type I and II and total fiber hypertrophy in the COL group only, indicating a robust independent effect of MIS on fCSA. Myonuclear domain increased similarly in both groups, whereas SC domain remained unchanged following RET. SC activation was similar between groups for all fiber types in the untrained state but showed a trend toward greater increases with MIS after RET (ES = 0.70). Conclusions SC responses to acute damaging exercise and long-term RET are predominantly similar in MIS and COL groups. However, MIS can induce greater increases in type II fCSA with RET and potentially SC activation following damage in the trained state.

Background Regular exercise can mitigate side effects of cancer treatment. However, only a small proportion of adults with cancer meet exercise guidelines, and older adults (> 65 years) are underrepresented in cancer rehabilitation research. Peer support facilitates health-promoting behaviours in general populations, but interventions merging exercise and peer support for older adults with cancer are not examined. The purpose of this study was to determine the feasibility and preliminary effectiveness of a virtual partner-based peer support exercise intervention for older adult female cancer survivors. Methods Older adult female cancer survivors with internet access and currently participating in < 150 min of moderate-vigorous physical activity per week were included in this study. Participants were matched with a partner and given a peer support guide, exercise guidelines, and a Fitbit Inspire©. In addition, intervention group dyads (AgeMatchPLUS) had weekly 1-h virtual sessions with a qualified exercise professional for 10 weeks. Dyads randomized to the control group (AgeMatch) independently supported their partner around exercise for 10 weeks. The primary outcome was feasibility, measured using retention and adherence rates. Secondary outcomes included exercise volume, social support, quality of life, physical function, and physical activity enjoyment. Descriptive statistics were used to report feasibility and an ANCOVA was used to explore between group differences on secondary outcomes at post-intervention (10 weeks post baseline) and post-tapering timepoints (14 weeks post baseline). Results Eighteen participants (9 dyads; mean age 72 years (SD: 5.7 years)) were included in the pilot trial. Retention and adherence rates to the AgeMatchPLUS intervention were 100% and 95% respectively. All but one participant was satisfied with the quality of their peer match. Preliminary effects were seen between group, favouring AgeMatchPLUS for exercise-related social support post-intervention (effect size (d) = 0.27, 95% CI = 0,0.54) and physical activity enjoyment at post-tapering (d = 0.25, 95% CI = 0,0.52) and favouring the AgeMatch group for 30 s sit-to-stand repetitions at post-tapering (d = 0.31, 95% CI = 0.004, 0.57). No other effects were found. Conclusions A virtual partner-based exercise intervention for older adults with cancer is feasible and shows preliminary effect benefits. Findings inform future trials aimed at increasing exercise in older adults with cancer. Trial registration Clinicaltrials.gov (ID: NCT05549479, date: 22/09/22).

A majority of human genes produce non-protein-coding RNA (ncRNA), and some have roles in development and disease. Neither ncRNA nor human skeletal muscle is ideally studied using short-read sequencing, so we used a customised RNA pipeline and network modelling to study cell-type specific ncRNA responses during muscle growth at scale. We completed five human resistance-training studies (n = 144 subjects), identifying 61% who successfully accrued muscle-mass. We produced 288 transcriptome-wide profiles and found 110 ncRNAs linked to muscle growth in vivo, while a transcriptome-driven network model demonstrated interactions via a number of discrete functional pathways and single-cell types. This analysis included established hypertrophy-related ncRNAs, including CYTOR – which was leukocyte-associated (FDR = 4.9×10−7). Novel hypertrophy-linked ncRNAs included PPP1CB-DT (myofibril assembly genes, FDR = 8.15×10−8), and EEF1A1P24 and TMSB4XP8 (vascular remodelling and angiogenesis genes, FDR = 2.77×10−5). We also discovered that hypertrophy lncRNA MYREM shows a specific myonuclear expression pattern in vivo. Our multi-layered analyses established that single-cell-associated ncRNA are identifiable from bulk muscle transcriptomic data and that hypertrophy-linked ncRNA genes mediate their association with muscle growth via multiple cell types and a set of interacting pathways.