RESEARCH: Studies from 27 May to 2 June 24
Sharing research and insights from coaches, scientists and athletes to help us improve endurance performance.
This week’s quick summary:
Higher perceived stress correlated with increased negative self-talk
Can parallel use of different running shoes decrease injury risk?
Post-exercise hot water immersion and hot water immersion in isolation
Variability in hemoglobin mass response to altitude training camps
Improvement of 10km time-trial cycling with motivational self-talk
PSYCHOLOGY: Negative self-talk in runners: Emotional intelligence and perceived stress as explanatory factors
A previous study I shared showed that implementing a structured self-talk intervention over five weeks can notably enhance running performance. Runners can have automatic negative thoughts and negative self-talk during races even when everything is going well. The authors of this study set out “to determine whether emotional intelligence factors could mitigate the relationship between stress and negative self-talk in runners”.
STUDY DETAILS
The participants were 1071 runners from a race in the Basque Country, Spain, aged 18-75 (mean=41.59; SD=9.95; 71.4% men).
Participants completed an online survey assessing perceived stress, negative self-talk, and EI factors days after the race.
The survey was administered shortly after the race, capturing immediate post-race reflections.
The survey measured perceived stress, negative self-talk, and four emotional intelligence factors: evaluation of others' emotions, regulation of emotions, appraisal of one's own emotions, and use of emotions.
Higher perceived stress correlated with increased negative self-talk. Evaluation of others' emotions and emotional regulation were linked to negative self-talk. Notably, the interaction between perceived stress and appraisal of one's own emotions explained negative self-talk, particularly in those with lower self-appraisal scores.
PRACTICAL TAKEAWAY
This study showed that runners experiencing high stress had increased negative self-talk and poor emotional regulation. While this is not something that is easy to resolve, there are steps that athletes can take before a race. My recommendation is for athletes to follow the same race-week routine before each race so it is familiar and makes the week easier. They can also use checklists, plan the logistics of travel and the timing around the race start carefully to remove any potential stress that can arise immediately prior to the race. Finally, where possible, closing any work-related projects or commitments prior to a race can remove some professional stress too.
EQUIPMENT: Can parallel use of different running shoes decrease running-related injury risk?
I’ve shared so many studies on shoes (see Equipment - SHOES) that most readers probably have multiple different pairs of supershoes and other shoes to train and race in! With all those shoes, does it make a difference having a shoe rotation and using different shoes for different types of runs? The authors in this study set out “to determine if runners who use concomitantly different pairs of running shoes are at a lower risk of running-related injury”.
STUDY DETAILS
264 recreational runners were monitored over a 22-week period.
Participants reported their running session characteristics, other sport activities, and injuries via an online platform.
RRI was defined as physical pain or complaints in the lower limbs or back, impeding planned running for at least one day.
87 participants experienced at least one RRI during the study.
Using more than one pair of running shoes was a protective factor against RRI (HR=0.614).
Previous injury increased the risk of RRI (HR=1.722).
Greater average session distance and weekly participation in other sports were linked to reduced RRI risk.
PRACTICAL TAKEAWAY
This study showed that using more than one pair of running shoes is a potential protective factor against running injuries. I recall an old idea that the EVA foam in running shoes compressed during running and that it needed more than 24 hours to decompress fully. This may be one of the reasons to rotate shoes along with the benefit of providing a slightly different stimulus of different cushioning and shoe elements. My recommendation is to have two to three pairs of shoes in rotation for training; two daily training shoes and one lighter or supershoe for faster training days.
HEAT: Post-exercise hot water immersion and hot water immersion in isolation enhance vascular, blood marker, and perceptual responses when compared to exercise alone
In the studies I’ve shared on heat acclimation, there has been good evidence to show that hot water immersion post-exercise can help with heat acclimation. In this study, the authors set out “to determine if post-exercise hot water immersion can synergise exercise-derived responses and differ from hot water immersion alone”.
STUDY DETAILS
Sixteen physically inactive middle-aged adults (nine males, seven females) participated in a randomized cross-over counterbalanced design study, involving two 30-min bouts separated by 10-min rest.
Conditions included moderate-intensity cycling (50% V̇O2 peak) and hot water immersion (HWI) at 40°C up to the mid-sternum with arms out. Blood samples and artery ultrasound scans were taken at baseline, immediately post-stressor one, post-stressor two, and recovery.
Brachial and superficial femoral artery shear rates were higher after moderate-intensity exercise followed by HWI (EX+HWI) and HWI alone (HWI+HWI) compared to exercise with rest (EX+REST).
Plasma nitrite levels increased significantly after EX+HWI and HWI+HWI, while serum interleukin-6 was higher after EX+HWI compared to EX+REST.
Serum cortisol was lower at 30 min in the HWI+HWI condition compared to EX+REST, and participants found EX+HWI and HWI+HWI more enjoyable than EX+REST.
PRACTICAL TAKEAWAY
This study showed that for physically inactive middle-aged adults, incorporating hot water immersion post-exercise can enhance vascular and blood marker responses. This suggests that combining exercise with HWI could be a beneficial strategy for improving vascular health and overall exercise enjoyment. I think that this is a useful finding, but at the same time it is important to stress that the hot water immersion protocols are not necessarily easy. In this study the HWI protocol was 30’ at 40C. My recommendation for people who want to try this approach to improving health, is to test the full duration of HWI to find out if it is something they can tolerate and enjoy and then decide whether or not it is a protocol to maintain in the long run.
ALTITUDE: Variability in hemoglobin mass response to altitude training camps
The studies I’ve shared on altitude training have shown that there is a benefit to this practice, while at the same time showing that there does seem to be individual variability in adaptation to the altitude stimulus. In this study, the authors set out “to evaluate whether athletes can be classified as responders or non-responders to altitude training based on changes in their total haemoglobin mass”.
STUDY DETAILS
59 elite endurance athletes from national teams participated in 82 altitude training camps (1350-2500m). Fifteen athletes attended multiple camps.
Altitude training camps were conducted, and total hemoglobin mass (tHb-mass) was measured using a CO rebreathing method before and after each camp.
Each athlete's tHb-mass response was tracked across multiple camps, with some athletes attending camps at least twice.
In 56% of camps, tHb-mass increased. This response rose to 65% in camps held above 2000m.
Among athletes attending multiple camps, 27% consistently showed positive tHb-mass responses, 13% consistently negative, and 60% varied. Altitude was the main factor influencing tHb-mass response, with male athletes showing greater increases than females.
PRACTICAL TAKEAWAY
This study showed that for endurance athletes, appropriate hypoxic stimulus during altitude training can likely increase tHb-mass. While there was variability in responses, the authors point out that “great inter- and intra-individual variability in tHb-mass response does not support classification of an athlete permanently as a responder or non-responder”. The implication is that it is important to tailor training approaches and control influencing factors for each athlete at altitude to maximise benefits. My recommendation is for athletes to perform blood tests before going to altitude to ensure they are in an appropriate state to adapt to the altitude, and then to plan a training camp at ~2000m for at least 14 days to see the benefits from this type of training.
PSYCHOLOGY: Improvement of 10km time-trial cycling with motivational self-talk compared with neutral self-talk
As I mentioned in the first study of this week’s newsletter, a five-week intervention of structured self-talk improved running performance. In this study, the authors set out to determine “whether motivational self-talk (M-ST) could reduce RPE and change pacing strategy, thereby enhancing 10km time-trial (TT) cycling performance in contrast to neutral self-talk (N-ST)”.
STUDY DETAILS
Fourteen men participated in the study.
Participants were divided into M-ST (n=7) and N-ST (n=7) groups after being matched based on their TT2 completion times.
Each participant completed four TTs (TT1-TT4).
Performance, power output, RPE, and oxygen uptake (VO2) were measured and compared across 1km segments using ANOVA.
After M-ST, TT4 completion time was faster (1078±96s) compared to TT3.
N-ST completion time remained similar (1165±111s) between TT3 and TT4.
The M-ST group achieved higher power output and VO2 in TT4 (6th-10th km).
RPE remained unchanged across both groups.
Confidence intervals indicated a likely performance improvement of 13-71s for the M-ST group (TT4 vs TT3).
PRACTICAL TAKEAWAY
The results of this study are interesting in that the RPE across both groups remained the same, even though the athletes using motivational self-talk went a little faster for that same effort. This suggests that even if motivational self-talk does not seem to make the effort easier, it can make an athlete faster. My recommendation is for athletes to first reduce stress leading up to a race to reduce the possibility of negative self-talk (see the first study above) and then to use motivational self-talk during their events. In this study, the participants took previous negative self-talk statements and prepared a counteractive positive, motivational statements to use when those negative thoughts arose. Therefore, to use this technique effectively takes reflection on previous thoughts and careful pre-event scripts to have at an athlete’s disposal when they need them.
Quick summary from last week’s paid newsletter
Paid subscribers receive a newsletter every week and have full access to all newsletters listed in the archives (385 studies and practical takeaways). Last week, the newsletter covered studies on the following topics:
A periodised diet does not improve performance compared to high-CHO diet
Effects of sodium replacement during an ultramarathon in the heat
Are pre‐race blood biomarkers associated with ultramarathon performance?
Power output at moderate-to-heavy intensity during prolonged exercise
Acute and chronic performance enhancement in rowing
Thank you fordiving into these particular studies this week and summarizing the overall outcomes and impacts on our training. I will definitely implement some of this data in mytraining and racing. Your information is both detailed and precise while providing clear easy to understand summaries. Thank you again.
And I love the cows!!