RESEARCH: Studies reviewed this week: 12 July 2021 to 18 July 2021

PHYSIOLOGY: Level, Uphill, and Downhill Running Economy Values Are Correlated Except on Steep Slopes

Running economy is an important contributor to performance outcomes. We know that running economy declines during an ultramarathon, but also that there may be times to sacrifice running economy for ultramarathon performance. Most trail and ultramarathon races have a range of climbs and different slopes so it's useful to understand how running economy varies between these environments. In this paper, the authors set out "to determine if level, uphill, and downhill energy cost of running (ECR) values were correlated at different slopes".

Their findings showed that:

Oxygen cost and ECR were correlated between all slope conditions for a given running speed, except between level and the steepest uphill slope. Specifically, the present study revealed that the intercorrelations diminish at steeper slopes, e.g., +20%.
he efficiency of uphill locomotion at +20% slope tends to become equal to that of concentric muscular work; thus, most of the work is to lift the body; the elastic energy storage and recovery and the bouncing mechanisms are lost. Consequently, the stretch-shortening cycle mechanism disappears, exacerbating the metabolic demand, as assessed by the higher blood lactate values and the cardiorespiratory responses.
Uphill conditions were characterized by higher step frequency and lower step length compared to level, whereas downhill conditions were characterized by shorter ground contact time.

PRACTICAL TAKEAWAY - running uphill on steep slopes requires a different running form and therefore needs specific training to develop.

PSYCHOLOGY: Playing videogames or using social media applications on smartphones causes mental fatigue and impairs decision-making performance in amateur boxers

The time immediately before a race can be a period filled with nervous energy but also with no outlet or action to take. With smartphones always available and on hand this may be a time that you look at your phone. In this study the authors set out to "analyze the effect of playing videogames and using social media applications on smartphones on decision-making and countermovement jump (CMJ) performance in amateur boxers". The authors found that:

Both attack and defense decision-making performance were worse in both [smartphone] and [video game] conditions compared to the [control] condition.
It was found a decrease in CMJ performance after all experimental conditions, with no difference between them.
Using social media applications on smartphones and playing video game impairs decision-making performance in amateur boxers, with no harms for CMJ performance.

PRACTICAL TAKEAWAY - don't use your phone immediately before a race.

NUTRITION: Nutrition and indoor cycling: a cross-sectional analysis of carbohydrate intake for online racing and training

In this study the authors aimed to assess the participants intake of carbohydrate (CHO) during indoor training and racing. "A mixed-methods approach consisting of a multiple-pass self-report food recall and questionnaire was used to determine total CHO intake pre, during and post-training or racing using a stationary trainer and compared with current guidelines for endurance exercise". The authors found that:

Mean CHO intake pre and post-ride was 0.7 and 1.0g kg/BM and 39·3g/h during training.
CHO intake was not different for races, ‘key sessions’ or higher ability cyclists.
Cyclists training or racing indoors do not meet current CHO recommendations for cycling performance.

PRACTICAL TAKEAWAY - most athletes do not meet the nutritional guidelines that would optimize their performance. Eat more CHO during training and racing!

ALTITUDE: Neuromuscular Adaptations after an Altitude Training Camp in Elite Judo Athletes

I shared many studies on altitude which show the performance benefits of training in this environment. This study is interesting because it looks at adaptation other than hematological values that can change during training at altitude. In this study the authors set out to "investigate neuromuscular adaptations in elite judo athletes after three weeks of power-oriented strength training at terrestrial altitude (2320 m)". The results showed that:

Significant differences were found between groups in terms of change in rate of torque development.
The difference between groups in changes in contraction time (CTTW) as a function of altitude was on the edge of significance. CTTW increased by 8.1% in the altitude group and remained statistically unchanged in the sea-level group.

PRACTICAL TAKEAWAY - training at altitude can provide additional benefits beyond those already identified as coming from increased red-blood cell mass.

IRON: Effect of different drinks on the absorption of non-heme iron from composite meals

Following on from the study on altitude above, an important consideration for achieving the physiological developments of training at altitude is ensuring that te body has enough nutrients, especially iron, to adapt to the altitude. This study looked at "the effect of various drinks on the absorption on non-heme iron". The authors found that:

Orange juice increased the iron absorption (85 per cent).
Pure alcohol and wine increased only slightly the percentage absorbed.
A reduction in iron absorption was seen when serving tea (62 per cent) or coffee (35 per cent) with the meals.

PRACTICAL TAKEAWAY - dirnk orange juice when you're trying to increase your iron intake and avoid caffeinated beverages like tea and coffee.

PSYCHOLOGY: World Championship and Olympic Games Experience Influences Future Medal Performance in Track-and-Field Athletes

This study looked at the success of athletes depending on the previous experience in high-level competition. The authors showed that:

(1) participation would improve the odds of future medal attainment.
(2) that advancement out of the first round of competition would improve the odds of future medal attainment.

PRACTICAL TAKEAWAY - experience at high-level competition can help improve future performance outcomes.

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