RESEARCH: studies I shared this week: 17 - 23 October 2022

All of the studies I've shared (~500 studies) are available on the RESOURCES PAGE.

PHYSIOLOGY: Reducing Impact Loading in Runners: A One-Year Follow-up


  1. The purpose of this study was to examine the acute and long-term effect of a gait retraining program aimed at teaching runners with high impact loading to run softer.
  2. The accelerometer signal was displayed in real time on a monitor. Participants were instructed to keep their TS below a line, placed at 50% of their baseline TS, and to make their footfalls softer.
  3. All variables of interest were significantly reduced post-retraining.
  4. Tibial shock (TS) was reduced by 32%, vertical impact peak by 21%, vertical instantaneous loading rate by 27%, and vertical average loading rate by 25%.
  5. Impact loading can be reduced through gait retraining and the results persist at least 1 yr.

PRACTICAL TAKEAWAY - gait retraining is possible. The effects appear to be long lasting.

CHO & PRO: The Effect of Ingesting Carbohydrate and Proteins on Athletic Performance


  1. The primary objective of the present systematic review and meta-analysis was to present the effect of co-ingesting carbohydrates and proteins on TTE performance when comparing to carbohydrate only.
  2. Most studies (n = 18 studies) provided whey as the protein source, four studies provided chocolate milk, three gave casein, one trial provided milk-based (i.e., casein and whey), and two trials provided plant-based protein, whilst six studies did not specify which protein source was provided.
  3. The majority of trials administered 4:1 of CHO:PRO, six gave 3:1 of CHO:PRO and three trials gave 2:1 of CHO:PRO.
  4. We found a significant overall effect in both TTE and TT performance, when CHO-PRO was ingested compared to CHO. A subgroup analysis demonstrated that this was significant when CHO-PRO was provided during and/or following an exercise bout.
  5. Moreover, results demonstrate an ergogenic effect of CHO-PRO, offering performance benefit when protein is added to an optimal amount of CHO supplement (e.g., matched for CHO content) as opposed to supplements matched for caloric content.

PRACTICAL TAKEAWAY - adding protein to in-race nutrition may be beneficial for performance.

CHO: The effects of glucose-fructose co-ingestion on repeated performance during a day of intensified rugby union training in professional academy players


  1. This study assessed the effects of glucose-fructose co-ingestion during recovery from high-intensity rugby training on subsequent performance.
  2. n. Identical rugby training sessions were separated by a 3-hour recovery period, during which participants ingested protein (0.3 g×kg BM/h) and carbohydrate-containing (0.8 g×kg BM×h-1) recovery drinks, comprised of glucose polymers (GLUCOSE ONLY) or a glucose-fructose mixture (GLUCOSE+FRUCTOSE).
  3. These data suggest that glucose-fructose co-ingestion as part of a carbohydrate-protein recovery solution does not further enhance recovery of performance during an intensified day of rugby training, compared to when the carbohydrates provided are glucose-based.

PRACTICAL TAKEAWAY - blends of glucose and fructose do not appear necessary for recovery between two closely placed sessions.

TRAINING: The Influence of Exercise Intensity on the Association Between kJ Spent and Various Training Loads in Professional Cycling


  1. The aim of this study is to explore the influence of exercise intensity on the association between kJ spent and different measures of l TL to arrive at valid measures of internal TL.
  2. Four years of field data were collected from 21 cyclists of a professional cycling team, including 11,716 training and race sessions. kJ spent was obtained from power output measurements and others TL’s were calculated based on the session Rating of Perceived Exertion (sRPE), heart rate (luTRIMP) and power output (TSS). Exercise intensity was expressed by the intensity factor (IF).
  3. Significant regression coefficients show that (kJ spent is a good predictor of sRPE, luTRIMP, as well as TSS. However, IF does not influence the associations between kJ spent and sRPE and luTRIMP, while the association with TSS is different when sessions are done with low or high IF.
  4. This means, in practice, that there will be a significant effect on the collected TSS values for sessions done with the same amount of kJ spent, but with a low or high intensity, while there is no effect on the collected sRPE and luTRIMP.

PRACTICAL TAKEAWAY - the authors suggest that using more than on training load metric may be necessary to understand the impacts of intensity on training.

CHO: Training Load and Carbohydrate Periodization Practices of Elite Male Australian Football Players


  1. The authors aimed to quantify (a) the periodization of physical loading and daily carbohydrate (CHO) intake across an in-season weekly microcycle of Australian Football and (b) the quantity and source of CHO consumed during game play and training.
  2. The daily CHO intake was also different between training days, with reported intakes of 1.8, 1.4, 2.5, and 4.5 g/kg body mass on GD-4, GD-3, GD-2, and GD-1, respectively.
  3. The CHO intake was greater during games (59 ± 19 g) compared with training, where in the former, 75% of the CHO consumed was from fluids as opposed to gels.
  4. The data also suggest Australian Football players underconsume CHO in relation to the physical demands of training and competition.

PRACTICAL TAKEAWAY - another study suggesting that professional athletes underconsume CHO compared to recommendations. There appears to be significant advantage compared to competitors by just following the guidelines alone.

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