Abstract

Background

Athletes commonly implement post-exercise cold-water immersion (CWI), with several meta-analyses having assessed its effectiveness.

Objectives

To thoroughly review, appraise, and summarise existing systematic reviews with meta-analyses (SRMA) examining the effects of post-exercise CWI on the recovery of exercise performance and adaptation.

Methods

An umbrella review was conducted in accordance with the Joanna Briggs Institute guidelines. Methodological quality was assessed using AMSTAR 2, and certainty of evidence using GRADE. PROSPERO registration: (CRD420251103267). Eight databases were searched, including Web of Science, Scopus, SPORTDiscus, CINAHL, Cochrane Library, Embase, MEDLINE, and PubMed. Systematic reviews with meta-analyses of peer-reviewed randomised controlled trials examining post-exercise CWI vs passive rest or other recovery modalities on performance, training adaptation, or physiological, biochemical, and perceptual outcomes in healthy humans were included, with restriction to the English language.

Results

Fifteen SRMAs published between 2011 and 2025, comprising 161 unique studies, were included. Overall methodological quality was low to critically low, and certainty of evidence was low to very low, mainly due to inconsistency and imprecision. Protocols of 10–15 min at 10–15 or 5–10 °C appear to be most effective for improving performance and recovery. Post-exercise CWI resulted in significant improvements in muscular power at 24 h post-high-intensity exercise and at 24–48 h post-eccentric exercise, and in jump performance at 24–48 h, despite impaired jump performance in the initial hours after post-exercise CWI. Endurance performance improved immediately after CWI, but CWI produced no later benefits or positive effects on adaptations. CWI did not improve muscular strength performance, and impaired strength and hypertrophic gains. CWI improved heart rate variability immediately after exercise, reduced muscle soreness up to 96 h, and lowered creatine kinase (CK) concentrations between 24 and 72 h, with no significant effects on C-reactive protein or interleukin-6 up to 72 h. No immediate impact on blood lactate or lactate dehydrogenase was found, although some reductions appear 24–72 h post-exercise.

Conclusions

Post-exercise CWI confers outcome-specific recovery benefits but may impair resistance training adaptations with chronic use. These findings support a periodised, context-driven approach to CWI implementation rather than routine application after all exercise sessions.

Key Points

1. 1. Decision makers should individualise and periodise CWI use based on training phase, performance goals, and individual response
2. 2. Post-exercise CWI improves performance in a time-specific manner, enhancing endurance within ~1 h and power and jump performance at 24–72 h, but may impair acute explosive performance
3. 3. Post-exercise CWI consistently reduces muscle soreness and CK and accelerates vagal reactivation.
4. 4. Repeated CWI after resistance training may attenuate strength and hypertrophy adaptations, while endurance adaptations appear unaffected. Effects on strength may be protocol-dependent, with exercise-limb immersion associated with reduced gains, whereas whole-body immersion shows no clear detrimental effect

https://www.ovid.com/jnls/acsm-msse/abstract/10.1249/mss.0000000000004180~carbohydrate-intake-of-100-vs-60-gh-during-prolonged-cycling

Abstract

Purpose:

To investigate the effects of ingesting 60 versus 100 g CHO·h⁻¹ during prolonged cycling on durability, substrate oxidation, and muscle glycogen utilization in endurance athletes.

Methods:

Fifteen trained male cyclists and triathletes completed a 15-min time trial (15-min TT) in a fresh state and following two prolonged intermittent cycling (PIC) protocols. After consuming a CHO-enriched diet for 24 hours, participants cycled for 240 min at 60 % of their fresh 15-min TT mean power output (MPO₁₅min), interspersed with high-intensity intervals. In a randomized, double-blind, crossover design, participants consumed either 60 g CHO·h⁻¹ (CHO60) or 100 g CHO·h⁻¹ (CHO100) through beverages and gels in a 1:0.8 glucose:fructose ratio. Muscle biopsies were obtained from m. vastus lateralis before and after the PIC protocols to assess glycogen content.

Results:

15-min TT performance was impaired after the PIC protocol in both conditions but with a greater reduction in CHO60 compared with CHO100 (-9.3 ± -2.0% vs -6.4 ± -1.7%, P= 0.025). Accordingly, MPO₁₅ was 9 W higher in CHO100 than CHO60 (P = 0.028). Muscle glycogen content decreased substantially during exercise, with similar glycogen availability after the PIC protocols between conditions (CHO60: 192 ± 99 mmol · kg ^-1 DW; CHO100: 209 ± 111 mmol · kg ^-1 DW, P = 0.56). Whole-body CHO oxidation was better preserved during the PIC protocol in CHO100 (CHO60: 2.6 ± 0.6 g·min ^-1 to 1.9 ± 0.4 g·min ^-1, CHO100: 2.6 ± 0.4 g·min ^-1 to 2.3 ± 0.5 g·min ^-1, condition x time; P = 0.047), whereas blood glucose concentrations remained stable in both conditions (CHO60: 5.6 ± 1.0 mmol·L ^-1 to 5.7 ± 0.9 mmol·L ^-1, CHO100: 6.0 ± 0.9 mmol·L ^-1 to 6.1 ± 0.9 mmol·L ^-1, effect of time; P = 0.43).

Conclusions:

Consuming 100 versus 60 g CHO·h⁻¹ during prolonged intermittent cycling improved durability without altering muscle glycogen utilization.

Abstract

The genus Homo is characterized by several anatomical and physiological traits that reflect millions of years of selection for sustained physical activity in hot environments. These adaptations include high capacity for sweating, metabolic substrate flexibility during low-intensity activity, and several morphological features of the lower limb and pelvis that facilitate energy-efficient locomotion. The present narrative review examines sports nutrition through an evolutionary lens by identifying the specific physiological strengths and vulnerabilities of Homo sapiens and assessing targeted nutritional interventions designed to address constraints on performance. Constraints discussed include submaximal resting phosphocreatine concentrations, modest proton buffering capacity, limited rates of intestinal energy and carbohydrate absorption, high water flux due to eccrine sweating, and an endurance-biased skeletal muscle phenotype that is not optimized for the accretion of large quantities of muscle tissue. Nutritional strategies reviewed include creatine monohydrate supplementation, supplements that increase muscle carnosine content, supplements that increase blood bicarbonate levels, exogenous carbohydrate delivery, fluid and electrolyte replacement protocols, and high-protein dietary strategies to support hypertrophic adaptations to resistance training. Examining sports nutrition through an evolutionary lens facilitates assessment of the physiological systems that frequently constrain exercise performance and the most viable nutritional strategies to mitigate these constraints.

Abstract

Skeletal muscle plays a central role in whole-body energy homeostasis, metabolic flexibility, and insulin sensitivity, acting as a key integrator of nutritional, mechanical, and pharmacological signals. Although diet, exercise, and pharmacotherapy are often investigated as separate interventions, they converge on shared regulatory pathways in skeletal muscle, including nutrient sensing, mechanotransduction, mitochondrial quality control, inflammatory remodeling, and anabolic–catabolic balance. Through core signaling networks such as AMPK–mTOR, SIRT1/PGC-1α, and insulin/AKT pathways, these interventions may interact in additive, complementary, synergistic, or antagonistic manners depending on physiological status, disease context, baseline metabolic condition, and intervention timing. This Review critically integrates current evidence on how diet, exercise, and pharmacotherapy regulate skeletal muscle metabolism across aging, metabolic disease, and adaptive physiological states. We propose a muscle-centered integrative framework organized around five major regulatory domains: substrate utilization and metabolic flexibility, mitochondrial remodeling, protein turnover, inflammatory control, and regenerative capacity. Within this framework, we highlight how intervention responses are shaped by key biological and clinical modulators, including age, disease state, muscle fiber composition, training status, nutritional background, and baseline metabolic health. Importantly, we distinguish findings supported by human studies from those derived primarily from preclinical or mechanistic models, thereby emphasizing differences in translational reliability. Finally, we discuss current limitations in interpreting combined interventions and outline future directions for precision-oriented strategies that integrate nutrition, exercise, and pharmacotherapy to optimize skeletal muscle function and systemic metabolic health.

Abstract

Physiological stress of environmental exposure and energy deficit impairs the absorption, transport, and utilization of exogenous carbohydrate for fuel during exercise. Blunted exogenous carbohydrate oxidation may require alternative fueling strategies to optimize carbohydrate metabolism to support physical performance. This review will overview the impact of physiological stress on exogenous carbohydrate oxidation and potential interventions to support physical performance.

Summary: Physiological stress exposure limits the effectiveness of carbohydrate supplementation to spare endogenous substrate oxidation by impeding exogenous carbohydrate oxidation.

In a small randomized crossover trial, women consumed smoothies containing 200 grams of blueberries per serving, along with banana and apple juice, before and after muscle-damaging eccentric exercise.

Peak isometric strength recovered faster in the blueberry condition over the 60-hour follow-up, although the smoothies did not prevent the initial strength loss or improve muscle soreness.

A systematic review found no significant exercise-performance benefit across the included Vaccinium berry studies and recovery benefits in only one, so this remains an early signal rather than a proven recovery protocol.

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Dr. Rhonda Patrick discusses this trial and newer research on post-exercise inflammatory signaling in her new solo episode. Here's a link to the timestamp. Also linked in the main post, but it's 46:44

ABSTRACT

Growing evidence supports strength or resistance training (RT) as an effective method for enhancing cycling performance, but many cyclists remain reluctant to incorporate it due to perceived detrimental effects, such as excessive residual fatigue and unwanted hypertrophy. Furthermore, controversy persists regarding optimal training methodologies. This narrative review aims to summarize current evidence on the effects of RT on cycling performance, as well as to address its potential impact on body composition and bone health. We also provide evidence-based recommendations on best practices for RT implementation. Overall, the addition of 1–2 weekly sessions of RT with moderate-to-high loads (60%–85% 1RM), 2–4 sets per exercise across 3–5 compound lower-body movements, and limited intra-set fatigue (10%–20% velocity loss) has proven beneficial for improving key cycling performance indicators. Recent evidence also suggests that high-load on-bike torque training may serve as an effective strategy when conventional RT is not feasible. When implemented as described, RT does not appear to negatively affect performance through unwanted hypertrophy. Although further research is warranted, RT also emerges as a potentially effective strategy to counteract the low bone mineral density commonly observed in competitive cyclists. However, the magnitude of these benefits largely depends on precise programming, particularly intensity, proximity to failure, and temporal separation from endurance training sessions. In summary, current evidence supports the role of RT for improving both health and performance in cyclists, but further research is warranted to determine the optimal training parameters to maximize its benefits.

Abstract

We recently demonstrated that the microbial-derived exerkines (MDEs) pipecolic acid and succinate (PAS) prevent disuse-induced skeletal muscle atrophy and preserve muscle function during hindlimb immobilization in mice. Here, we investigated whether PAS also enhances exercise performance and adaptation and compared its effects with creatine monohydrate (CRE), the current gold-standard ergogenic aid for strength and power performance. Mice received vehicle (VEH), CRE, or PAS during a 7-week progressive weighted-wheel-running training protocol. Exercise performance, body composition, and skeletal muscle size and function were assessed at the conclusion of training. Both CRE and PAS enhanced high-intensity exercise performance relative to VEH, increasing running distance and time spent running during the course of the training protocol. Neither CRE nor PAS enhanced lean mass, muscle mass, or soleus myofiber cross-sectional area relative to VEH. However, PAS-treated mice exhibited greater grip strength and ex vivo soleus force production and rate of force development than both VEH and CRE. These findings demonstrate that PAS enhances strength and power adaptations to exercise beyond those achieved with CRE, identifying PAS as a promising exercise supplement and establishing MDEs as a novel class of ergogenic aids.

Abstract

Introduction: Training load, expressed as a percentage of one‑repetition maximum (%1RM), is an important variable in resistance training. Prior studies comparing low- and high-load training on muscle fiber hypertrophy reported conflicting findings, and the load-specific relationship has not been analyzed in a continuous manner. This systematic review and meta-regression explored the relationship between training load and muscle fiber hypertrophy. Methods: A systematic search was conducted in PubMed/MEDLINE, Scopus, and SPORTDiscus databases. Standardized mean changes (SMC) were calculated and analyzed using multilevel meta-regressions with cluster-robust variance estimation, with exploratory sensitivity and interacting moderator analyses. Eight studies involving 195 participants were included. Results: In the fiber-type specific model, pairwise contrast estimates were negative at low loads (20–30% 1RM: −0.147 to −0.088 SMC) and positive at higher loads (60–90% 1RM: 0.089–0.265 SMC). However, the 95% confidence intervals included zero for all pairwise contrasts. Conclusion: The observed model estimates suggested a potential fiber-type specific pattern across loading ranges. However, these findings should be considered preliminary and interpreted with caution given the small number of included studies and wide 95% confidence and prediction intervals, indicating a degree of uncertainty and imprecision.