Who Studies This Stuff?

So my quest for knowledge keeps growing.  I frequently checkout different journals online.  I’m not talking blogs.  I’m talking about studies that have been done and then reported on.  Below are a couple that I found at the the Journal of Science and Medicine in Sport.

Maximising performance in triathlon: Applied physiological and nutritional aspects of elite and non-elite competitions

The aim of this study was to investigate the effect of constant versus variable power output cycling exercise on subsequent high-intensity, running performance. Eight triathletes completed two testing sessions (in a random order), which required the subjects to perform 30min of cycling at either, a constant power output (90% of the lactate threshold), or a variable power output with power output alternating every 5min (±20% of the constant workload). Each cycling bout was immediately followed by a high-intensity treadmill run (16.7±0.7kmh−1) to exhaustion. No significant differences were found for mean metabolic values or power output between cycling conditions. However, a significant (P<0.05) improvement in run time to exhaustion was reported after 30min of variable cycling (15:09±4:43min) compared to constant cycling (10:51±3:32min). The results of this study demonstrate that, despite similar average physiological responses during 30min of cycling, variable-intensity cycling results in an improved running performance compared to constant-intensity cycling. It is hypothesised that the reduced power output in the final 5min of variable cycling protocol may allow recovery before transition, however the mechanisms involved cannot be determined from the current study.

This is something I am intriqued with.  Since most triathletes spend loads of time at constant pace or “steady state”.  By changing power imputs the athletes were able to run faster off the bike.  Now, as this article states, it could be due to the decrease in power in the last interval (so the last 5 minutes were done at a much easier level).  Even so, the total average power imputs were the same in both experiments.

Effect of post-exercise sauna bathing on the endurance performance of competitive male runners

The physiological adaptations to sauna bathing could enhance endurance performance. We have therefore performed a cross-over study in which six male distance runners completed 3wk of post-training sauna bathing and 3wk of control training, with a 3wk washout. During the sauna period, subjects sat in a humid sauna at 89.9±2.0°C (mean±standard deviation) immediately post-exercise for 31±5min on 12.7±2.1 occasions. The performance test was a ∼15min treadmill run to exhaustion at the runner’s current best speed over 5km. The test was performed on the 1st and 2nd day following completion of the sauna and control periods, and the times were averaged. Plasma, red-cell and total blood volume were measured via Evans blue dye dilution immediately prior to the first run to exhaustion for each period. Relative to control, sauna bathing increased run time to exhaustion by 32% (90% confidence limits 21–43%), which is equivalent to an enhancement of ∼1.9% (1.3–2.4%) in an endurance time trial. Plasma and red-cell volumes increased by 7.1% (5.6–8.7%) and 3.5% (−0.8% to 8.1%) respectively, after sauna relative to control. Change in performance had high correlations with change in plasma volume (0.96, 0.76–0.99) and total blood volume (0.94, 0.66–0.99), but the correlation with change in red cell volume was unclear (0.48, −0.40 to 0.90). We conclude that 3wk of post-exercise sauna bathing produced a worthwhile enhancement of endurance running performance, probably by increasing blood volume.

So this test was brutal!  You had to run at your 5K pace on a treadmill for 15mins.  Immediately after you sat in a sauna for 30 (+/-12mins).  If you’ve done the sauna thing, sitting in it for 30mins is really hard!  Especially 89.9 degrees celsius!  Wow…

Gender differences in metabolism; nutrition and supplements

For many decades researchers did not consider that there were any differences between the genders in the metabolic response to exercise. As a result, nutritional recommendations and exercise training prescriptions have not considered the potential for gender specific responses. More recently, we and others have demonstrated that females oxidize proportionately more lipid and less carbohydrate during endurance exercise as compared to males. The oxidation of amino acids is similarly lower in females as compared to males during exercise. These gender differences are partially mediated by a higher estrogen concentration in females. Specific areas where there are gender differences in nutritional/supplement recommendations include carbohydrate (CHO) nutrition, protein requirements and creatine (CRM) supplementation. We have shown that females do not carbohydrate load in response to an increase in dietary carbohydrate when expressed as a percentage of total energy intake (i.e., 55–75%), however if they consume >8g CHO·kg−1·d−1, they show similar increases as compared to males. Top sport male and female athletes require somewhat more dietary protein as compared to sedentary persons. The maximal increase is ∼100% for elite male athletes and ∼50–60% for elite female athletes. Fortunately, most athletes habitually consume this level of protein intake. We have recently demonstrated that females show a lesser increase in lean body mass following acute CRM loading as compared to males. Females also did not show reductions in protein breakdown in response to CRM loading, whereas males did. In the future I expect that there will be further research from which gender specific nutritional/supplement recommendations can be made.

It would be nice to know a little more on this topic.  Hopefully it will be open to the public soon.

Yeah I’m a nerd for looking for this stuff.  But information is power!

Happy (Readin) Trainin!

CWR