RESEARCH: studies shared from 27 Feb to 5 Mar 23

This week's quick summary:

  • Foam rolling the ITB and for range of motion
  • The relationship between VO2 Max and uphill race performance
  • Periodization of altitude training
  • Bone stress injuries when using carbon fibre plated shoes
  • Heat acclimation and muscle-tendon unit properties


PHYSIOLOGY: The effects of an acute bout of foam rolling on hip range of motion on different tissues

Previous research I've shared shows that foam rolling does not improve performance, but that an 18-week intervention of strength training and foam rolling may prevent injuries. This study looked at the acute impact of a single bout foam rolling on the ITB.

STUDY DETAILS

  1. It is believed that foam rolling (FR) can remove restrictions due to fascial adhesions, thus improving range of motion (ROM).
  2. The purpose of this study was to compare the acute effect of a single bout of foam rolling (FR) over the Iliotibial Band (ITB) compared to FR over the gluteal muscle group on hip adduction passive range of motion (PROM).
  3. Each participant performed three sessions: FR over tissue devoid of muscle, the ITB (PFR), FR over contractile tissue, the gluteal muscles (AFR), and a session without FR (control) in a randomized order.
  4. Post-hoc analysis showed the AFR post-test measure was significantly different from both control and PFR counterparts.
  5. FR over the gluteal muscle group lead to a 14.8% improvement in hip adduction ROM, with PFR only a 2% improvement.
  6. A single bout of FR over a myofascial group appears to increase PROM in healthy young adults, whereas FR over the ITB itself (primarily fascial tissue) does not.

PRACTICAL TAKEAWAY

A single-dose of foam rolling over the ITB does not appear to have an impact. However, foam rolling the muscles in the upper leg did show an increase of range of motion. Therefore, it appears that the most effective use of a foam roller is to roll the muscles (and not tendons) which should create greater range of motion and perhaps alleviate pain or injury symptoms. My recommendation is to use a foam roller as a form of massage over the muscles in the area with an issue.


PHYSIOLOGY: Eager to set a record in a vertical race? Test your VO2max first!

STUDY DETAILS

  1. We investigated the relationship between maximal oxygen consumption (VO2max) and performance in vertical races (VRs).
  2. The relationship between performance and VO2max was modelled separately for national (NVRs), international (IVRs), and VRs of current pole-unassisted and pole-assisted vertical kilometre (VK) records (RVRs).
  3. Three different exponential models described the relationship between performance and VO2max in IVRs (R2=0.96), NRs (R2=0.91) and RVRs (R2=0.97).
  4. Estimated VO2max requirements (with 95% CI) to win/set a record time in IVRs were 86/89 and 74/77 mL/min/kg, for males and females, respectively, 86/90 and 75/77 mL/min/kg in RVRs, decreasing to 84/88 and 67/71 mL/min/kg in NVRs.
  5. These data provide mean VO2max requirements for mountain runners to win and establish new records in VRs and stimulate new research on the energy cost of off-road running.

PRACTICAL TAKEAWAY

These are the strongest relationships between a physical metric, VO2 Max, and performance that I've seen with 91-97% of performance explained by V02 Max values. An athlete needs a very high VO2 Max to compete in vertical races and while some of that is genetically determined, it is possible to train to improve an athlete's VO2 Max.
There is plenty of speculation on the best way to train at this intensity (search for VO2 Max on the resources page). My recommendation is to start with HIDIT intervals, progress to intervals of 3-5' duration, and then perform fast-start intervals. This progression could be performed over a traditional training plan increasing the training load over time, or by performing focused blocks of training.


ALTITUDE: Periodization of altitude training: A collective case study of high-level swimmers

I have shared a large number of studies on altitude in the past (search for altitude on my resources page). This study is interesting because it shows what world class athletes are actually doing and the benefit they achieved from their altitude training approach.

STUDY DETAILS

  1. The altitude training of four female and two male international swimmers in selected seasons was examined using a collective case study approach.
  2. All swimmers were a medalist in World (WC) and/or European Championships (EC) 2013, 2014, 2016 and 2018 in short or long course competition.
  3. A traditional periodization model was employed using three macrocycles with 3–4 altitude camps (duration 21–24 days each) scheduled over the season, following a polarized training intensity distribution (TID) with a volume ranged between 729 km and 862 km.
  4. The timing of return from altitude prior to competition was between 20–32 days, with 28 days the most common period.
  5. Competition performance following the altitude training camps improved by 0.6% ± 0.8%.
  6. Hemoglobin concentration increased 4.9% from pre-to post-altitude training camps, while hematocrit increased by 4.5%.

PRACTICAL TAKEAWAY

Following the research-based guidelines for altitude training is very effective. It's not possible for all athletes to go on four multi-week training camps a year, however, the principles they used can still be applied for smaller doses or individual training camps. Therefore, when considering altitude training, an athlete should plan this carefully and follow best practices (altitude camps of 21-24 days at ~2000m allowing ~28 days at sea level again before competition).


EQUIPMENT: Bone stress injuries in runners using carbon fiber plate footwear

In the last few weeks I've shared studies showing the benefit of supershoes which makes them a necessity for performance in road races (see the articles on my Substack page). While there are individual variations between athletes and the need to select the best supershoe for each individual, the potential for injuries has not been explored. This set of five case studies provides a useful warning about potential issues that need further exploration.

STUDY DETAILS

  1. The association of this footwear with injuries has been a topic of debate clinically, but not described in the literature.
  2. In this Current Opinion article, illustrated by a case series of five navicular bone stress injuries in highly competitive running athletes, we discuss the development of running-related injuries in association with the use of carbon fiber plate footwear.
  3. This article is intended:
    • to raise awareness on possible health concerns around the use of carbon fiber plate footwear
    • to suggest a slow gradual transition from habitual to carbon fiber plate footwear
    • to foster medical research related to carbon fiber plate technology and injuries.
  4. Prior experience with metatarsal BSI with minimalist footwear led shoe companies to develop a more gradual program for transitioning to minimalist shoes; it is plausible that similar advances could be developed by shoe companies, researchers and clinicians to promote safety in sports when using CFP footwear.

PRACTICAL TAKEAWAY

It is important to be aware that any new equipment could cause a change in how an athlete runs and performs. This could be positive and result in better performances, it could be negative and result in injury, or perhaps some combination of both postive and negative outcomes. Supershoes are resulting in better performances, but there may be some cost to that. My recommendation would be to transition slowly to new shoes and allow the body time to adapt.
I thought the advice from Jorge Martinez on Twitter was very good:
If you plan using SS, 1) pick model based on your needs (running style, stability limitations, etc.) 2) adapt to them in training (start with easy runs, do a bit of everything) & 3) depending on your running speed, a trainer SS may be best (less $, more stable, etc.).


HEAT: Active heat acclimation does not alter muscle-tendon unit properties

Similar to altitude, heat is a topic I'm particularly interested in (search for heat on the resources page). This study adds to the research I've shared in the past as it investigated any potential downsides of heat acclimation on the muscle-tendon unit.

STUDY DETAILS

  1. This study investigated the effect of active heat acclimation (HA) on gastrocnemius medialis (GM) muscle-tendon properties.
  2. Thirty recreationally active participants performed 13 low-intensity cycling sessions, distributed over a 17-days period in hot (HA: ⁓38 °C, ⁓58% relative humidity [RH]; n = 15) or in temperate environment (CON: ⁓23 °C, ⁓35% RH; n = 15).
  3. Core temperature decreased from the first to the last session in HA (-0.4 ± 0.3 °C; P = 0.015), while sweat rate increased (+0.4 ± 0.3 L.h-1; P = 0.010), suggesting effective HA; whereas no changes were observed in CON.
  4. Muscle-tendon unit properties (i.e., maximal and explosive isometric torque production, contractile properties, voluntary activation, joint and fascicular force-velocity relationship, passive muscle and active tendon stiffness) and vertical jump performance did not show training (P ≥ 0.067) or group × training interaction (P ≥ 0.232) effects.
  5. Effective active heat acclimation does not alter muscle-tendon properties.

PRACTICAL TAKEAWAY

There does not appear to be any negative impact from heat acclimation on the muscle-tendon unit. Therefore, when preparing to race in hot environments, or when training at heat camps, this is not a concern an athlete needs to have. Heat acclimation appears to be safe with respect to muscle-tendon adaptation.


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