You may already have seen the link to Stuart Philipps latest "Review of Higher Dietary Protein Diets in Weight Loss" with a "A Focus on Athletes" on Facebook. For those of you who have been following the SuppVersity News there's probably little new information in the document, though. When I read the paragraph about optimal protein intakes for maximal muscle retention, I still thought that it may be worth to remind you of the results of the Pasiokos study which clearly suggest that eating more protein is not always going to increase the net protein retention when you are dieting.
A fact that brings me back to Philipps' review in which he points out that dieters commonly overlook that any increase in protein intake will go at the expense of either fat or carbohydrate. A "side effect" that could be particularly problematic for athletes, for whom Philipps recommends (just like I do) "to balance the increase in protein consumption with what macronutrient is reduced" (Phillips. 2014). In particular, athletes should "focus on reducing intakes of lipids to allow carbohydrate intakes to achieve performance" (Phillips. 2014).
After this brief introductory interlude, I would like to get to the actual topic at hand, a brief overview of a couple of interesting, but not exactly "full-article worthy" papers from the realms of exercise, nutrition and supplementation:
- Low volume, high intensity the exercise key to perfect health? A recent paper in the latest edition of Sports Medicine reviewed the health benefits of two different low volume exercise regimen: The classic sprint interval training (black spikes in Figure 1) and a HIIT protocol (grey bars in Figure 1).
The researchers from the McMaster University in Hamilton, Ontario, highlight that the currently available evidence is largely based on short-term interventions. And while long(er)-term interventions would be needed to " to advance our basic understanding of how manipulating the exercise stimulus translates into physiological remodeling" (Gibala. 2014), it can already be said that...
Figure 1: Comparison of the power output (% of VO2peak) during sprint interval training (SIT, black peaks), high intensity interval training (HIIT, grey bars) and moderate intenstity continuous training (MICT, striped box)
This is particularly germane given that ‘lack of time’ remains the most commonly cited barrier to regular exercise participation, and considering evidence that suggests that low-volume interval training is perceived to be more enjoyable than MICT." (Gibala. 2014)
Figure 2: Everything works, as long as you pick the right type of exercise for your type.
- Low dose caffeine (200mg) not effective for everyone - A recent study from the University of Guelph found that low doses of caffeine (<3 mg/kg body
mass, ~200 mg) can be ergogenic in some exercise and
sport situations, but for most athletes they will not alter the peripheral wholebody responses to exercise, or improve vigilance, alertness, and mood and cognitive processes during and after
Figure 3: Effects of ingesting no caffeine (0) or 3, 6 or 9 mg/kg body mass of caffeine (dose) on running time to exhaustion at ~85 % of VO2max (Graham. 1995).
- Science-Based Recommendations for Training
to Maximize Concurrent Training - Right from the desk of Keith Baar comes a set of recommendations to maximize the benefits of concomitant training, i.e. combined / sequential endurance and strength training that consists of a set of four tips:
- Do HIIT in the AM: Any high-intensity endurance training sessions should be performed early in the day. Then, a period of recovery of at least 3 h should be given, so that AMPK and SIRT1 activity can return to baseline levels, before resistance exercise is performed. This suggestion is based on the fact that AMPK activity increases rapidly and then returns to baseline levels within the first 3 h after high-intensity exercise (Wojtaszewski. 2000), whereas mTORC1 activity can be maintained for at least 18 h after resistance exercise (Baar. 1999; MacKenzie. 2009).
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In view of the fact that Baar recommends to do your RT sessions later in the day, it is also advisable to consume another protein shake right before bed to maximize the synthetic response overnight (learn more).
- Fully refuel between the morning high-intensity
endurance training session and the afternoon strength
session: It's not going to reduce the exercise induced increase in AMPK and SIRT1 activation, but will allow you to perform at maximal intensity during your resistance training session later in the day.
As Baar points, out athletes who have to diet during certain phases of their training cycle should make sure to "reserve a portion of the offseason (and short periods in season) exclusively for increasing muscle size and strength and then use higher dietary protein intakes to maintain that muscle mass as the aerobic load increases through the season" (Baar. 2014).
- If you do low-intensity cardio, do your resistance training right after cardio: To improve the endurance response to lower-intensity
endurance training sessions and provide a strong
strength stimulus, Baar recommends performing strength training immediately after low-intensity, non-depleting,
Performing a strength session immediately after a low-intensity endurance session results in a greater stimulus for endurance adaptation than the low-intensity endurance session alone (Wang. 2011) and the low-intensity session will not affect signaling pathways regulating strength gains (Coffey. 2009; Lundberg. 2012; Apró. 2013).
- Apró, William, et al. "Resistance exercise induced mTORC1 signaling is not impaired by subsequent endurance exercise in human skeletal muscle." American Journal of Physiology-Endocrinology and Metabolism 305.1 (2013): E22-E32.
- Baar, Keith, and Karyn Esser. "Phosphorylation of p70S6kcorrelates with increased skeletal muscle mass following resistance exercise." American Journal of Physiology-Cell Physiology 276.1 (1999): C120-C127.
- Coffey, Vernon G., et al. "Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle." Journal of applied physiology 106.4 (2009): 1187-1197.
- Graham, T. E., and L. L. Spriet. "Metabolic, catecholamine, and exercise performance responses to various doses of caffeine." Journal of Applied Physiology 78.3 (1995): 867-874.
- Lundberg, Tommy R., et al. "Aerobic exercise alters skeletal muscle molecular responses to resistance exercise." Medicine and science in sports and exercise 44.9 (2012): 1680-1688.
- Pasiakos, Stefan M., et al. "Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial." The FASEB Journal 27.9 (2013): 3837-3847.
- van Loon, Luc JC, and Kevin D. Tipton. "Concluding Remarks: Nutritional Strategies to Support the Adaptive Response to Prolonged Exercise Training." (2013): 135-141.
- Wall, et al. "Dietary Protein Considerations to Support Active Aging." Sports Med (2014) 44 (Suppl 2):S185–S194.
- Wang, Li, et al. "Resistance exercise enhances the molecular signaling of mitochondrial biogenesis induced by endurance exercise in human skeletal muscle." Journal of applied physiology 111.5 (2011): 1335-1344.
- Wojtaszewski, Jørgen FP, et al. "Isoform-specific and exercise intensity-dependent activation of 5′-AMP-activated protein kinase in human skeletal muscle." The Journal of physiology 528.1 (2000): 221-226.