RESEARCH: Studies reviewed this week: 08 March 2021 to 14 March 2021

TRAINING: Comparison of a Traditional Graded Exercise Protocol With a Self-Paced 1-km Test to Assess Maximal Oxygen Consumption

This study set out to test a traditional graded exercise test (GXT) with a 1-km self-paced running test as means to determine VO2 Max. The authors found that:

The 1-km test produced significantly higher VO2max values.
This indicates that a 1-km running test performed on a nonmotorized treadmill could serve as a simple and sport-specific alternative for the assessment of VO2max.

PRACTICAL TAKEAWAY - it appears that a 1km running test may be a good means of determining VO2 Max. Perhaps the training level of these athletes impacted how effectively they could perform an open-ended GXT so perhaps in addition to being sports-specific, the 1km running test may be training-level specific too.

NUTRITION: Fueling for Performance

This is a useful and comprehensive guide to fueling for sports performance.

A few notes and highlights I took were:

Nutritional recommendations need to be individualized for each athlete; thus, clinicians should be well informed to help determine proper caloric, macronutrient, micronutrient, and hydration intake based on the athlete’s sport demands and training goals.
An athlete’s RMR along with his or her weight goals (loss, maintenance, or gain) are used to determine training macronutrient levels for protein, carbohydrate, and fat ratios.
Micronutrient intake or supplementation should be determined based on identified nutrient deficiencies and/or dietary restrictions (eg, vegan, vegetarian) to assist with injury prevention and enhance injury recovery.
For bone healing and stress fractures, athletes should have adequate intake of calcium and vitamin D. For athletes with multiple stress fractures, clinicians should consider evaluating vitamin D and other laboratory studies as well as assessing female athletes for disordered eating practices. Zinc, vitamin A, vitamin C, and other micronutrients have a clear association with wound healing, tissue repair, and growth.
Although inflammation is a necessary response to acute injury and is needed in the first phases of healing, prolonged inflammation may decrease recovery, and athletes should consider a diet higher in omega-3 oils such as salmon, flaxseed, and chia seeds.49 Athletes should also look for foods high in vitamin C as it has anti-inflammatory properties and also has been shown to promote collagen synthesis.50 Foods high in vitamin C include citrus fruits, red and yellow bell peppers, dark leafy greens, kiwi, broccoli, berries, tomatoes, mango, and papaya.

PRACTICAL TAKEAWAY - fueling for performance is multifaceted and requires careful consideration to achieve optimal outcomes.

STRENGTH: Maximal strength training improves running economy in distance runners

I've shares some studies showing that strength training can improve running economy. This study "investigated the effect of maximal strength training on running economy (RE) at 70% of maximal oxygen consumption and time to exhaustion at maximal aerobic speed (MAS)".

The intervention protocol was as follows:

The intervention group (four males and four females) performed half-squats, four sets of four repetitions maximum, three times per week for 8 wk, as a supplement to their normal endurance training.

The results showed that:

Maximal strength training for 8 wk improved RE and increased time to exhaustion at MAS among well-trained, long-distance runners, without change in maximal oxygen uptake or body weight.

PRACTICAL TAKEAWAY - strength training is a valuable component of a running programme for increasing running economy.

STRENGTH: Strength Training Improves Exercise Economy in Triathletes During a Simulated Triathlon

Building on the study above about strength training, this study set out "to investigate physiological outcomes in long-distance (LD) triathletes when strength training (ST) was completed concurrently to endurance training". In many ways, long-distance triathlon studies are a useful proxy for ultramarathon runners because the accumulated fatigue and duration of the event mean that the run leg of a triathlon is more similar to an ultramarathon than a normal marathon is.

The intervention protocol was extensive:

26 weeks of concurrent endurance and ST progressing from moderate (8–12 repetitions, ≤75% of 1-repetition maximum, weeks 0–12) to heavy loads (1–6 repetitions, ≥85% of 1-repetition maximum, weeks 14–26).

The authors found that:

The addition of progressive load ST to LD triathletes’ training programs can significantly improve running and cycling economy without an increase in body mass.

PRACTICAL TAKEAWAY - strength training can improve running economy without increasing body mass.

NUTRITION: Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis

"This narrative review provides an overview of the effect of coffee brew; its by-products; and its components on the gastrointestinal mucosa (mainly involved in permeability, secretion, and proliferation), the neural and non-neural components of the gut wall responsible for its motor function, and the brain–gut axis."

A few notes and highlights:

Coffee composition depends on many factors such as coffee origin, method of preparation (water steam temperature, roasting, etc), resulting in variable effects on physiology and microbiome.
Importantly, the participants were daily coffee consumers, and the study was performed in non-stressful conditions. There was no effect of coffee on self-reported anxiety levels. Furthermore, the participants reported a very low score (1 out of 10) for all the questions pertaining to negative gastrointestinal symptoms (i.e., abdominal discomfort, bloating, dyspepsia, and heartburn), chronic stress, and negative feelings, whereas the score was high (9 out of 10) for all the questions pertaining to positive feelings.
Epidemiological studies have suggested that coffee brew may exert multiple effects on the digestive tract, including antioxidant, anti-inflammatory, and antiproliferative effects on the mucosa, and pro-motility effects on the muscle layers.

PRACTICAL TAKEAWAY - coffee is complex with mutliple factors such as caffeine, polyphenols and other constituent parts affecting how it impacts each individual. I would highly recommend reading this study to learn more.

TRAINING: Effect of acute static stretch on maximal muscle performance

I recently shared a study on the impact of stretching on running performance and running economy. The takeaway from that study was to perform a dynamic stretching routine before training and if performing static stretching to keep the stretches to less than 60". This systematic review investigated "the literature describing responses to acute static muscle stretch".

The authors concluded that:

The detrimental effects of static stretch are mainly limited to longer durations (≥ 60 s), which may not be typically used during preexercise routines in clinical, healthy, or athletic populations.
Shorter durations of stretch (less than 60") can be performed in a preexercise routine without compromising maximal muscle performance.

PRACTICAL TAKEAWAY - if you are going to do static stretching, keep the stretches to less than 60" per muscle group.

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