|This is about as intense as it gets in PA sessions. What about HIIT and RT in schools?|
Today's installment revolves around five question: (a) Who benefits from acute cold-water immersion? (b) Which athletes benefit most from altitude training? (c) Is inspiratory muscle training actually ergogenic? And (d) will exercise in the cold impair your immune function?
- Acute Responses to Resistance and High Intensity Interval Training in Adolescents (Harris. 2016) - HIIT may no longer be in the news daily, but it is still appealing to athletes of all ages - including adolescents. Accordingly, a recent study took a closer look at the acute physiological responses to HIIT and compared it to resistance training (RT) sessions that were matched for time and required comparable effort, in a school setting.
Seventeen early adolescents (12.9 +/- 0.3 y) performed both RT (2-5 repetitions perceived short of failure at the end of each set) and HIIT (90% of age predicted maximum heart rate), equated for total work set and recovery period durations comprising of 12 'sets' of 30 s work followed by 30 s recovery (total session time 12 min). Variables of interest included oxygen consumption, set and session heart rate (HR) and rate of perceived exertion (RPE), and change in salivary cortisol (SC), salivary alpha amylase (S[alpha]A), and blood lactate (BL) from pre- to post-session.
Figure 1: Acute rel. increase in VO2 and lactate levels after resistance training and HIIT (Harris. 2016)
Eventually, the study does therefore confirm that intermittent forays into high, but not supra-maximal intensity exercise is a potent physiological stimulus in adolescents. What I would like to highlight, though, is the fact that this isn't true only for HIIT, but also for resistance training which is still falsely regarded solely as strength and muscle builder.
- Controlled Frequency Breathing Reduces Inspiratory Muscle Fatigue, but is Another Training Technique that does not translate into Real World Benefits (Brutch. 2016) - Controlled frequency breathing (CFB) is a common swim training modality involving holding one's breath for about 7 to 10 strokes before taking another breath.
In their latest study, Burtch et al. sought to examine the effects of CFB training on reducing respiratory muscle fatigue. Competitive college swimmers were randomly divided into either the CFB group that breathed every 7 to 10 strokes, or a control group that breathed every 3-4 strokes. Twenty swimmers completed the study. The training intervention included 5-6 weeks (16 sessions) of 12x50-m repetitions with breathing 8-10 breaths per 50m (control group), or 2-3 breaths per 50-m (CFB group). Inspiratory muscle fatigue was defined as the decrease in maximal inspiratory mouth-pressure (MIP) between rest and 46s after a 200 yard free-style swimming race [115s (SD 7)]. Aerobic capacity, pulmonary diffusing capacity, and running economy were also measured pre and post-training.
Figure 2: Mechanisms by which inspiratory muscle training improves performance (Brunell University)
"In conclusion, CFB training appears to prevent inspiratory muscle fatigue yet no difference was found in performance outcomes," the authors write and forget to highlight that this is not the first study to show that many experimentally verified benefits on potential determinants of exercise performance (cf. Figure 2) leave the actual performance variables unchanged - or, at least not significantly improved (here: -0.1 +/- 1.5s in CFP vs. +1.8 +/- 4.6 in the control group - a tentative benefit).
- Can cold water immersion enhance recovery in elite Olympic weightlifters? An individualized perspective (Schimpchen. 2016) - I hope you still remember that your goals determine whether you should or should not use cold water immersion, right? The thing about the impaired gains if you do it in a training phase...?
Using Ice / Cold Water Immersion After Workouts Will Impair Muscle & Strength Gains and Vascular Adaptations | more
The entire German male Olympic weightlifting national team participated in the study (n=7), ensuring collection of data from elite athletes only.
Using a randomized cross-over design, the athletes went through two high intensity training microcycles consisting of five training sessions that were either followed by a cold water immersion or passive recovery. Barbell speed in a snatch pull movement, blood parameters as well as subjective ratings of general fatigue and recovery were assessed throughout the study.
"In general, CWI did not prove to be an effective tool to enhance recovery in elite Olympic weightlifters over a three day intensive training period," Schimpchen et al. conclude, but add: "However, even though the group was rather homogeneous with regard to performance, there were considerable inter-subject differences in their response to CWI. It appears that athletes are best advised on a case-by-case basis" (Schimpchen. 2016).
- The maximal mechanical capabilities of leg extensors muscles to generate velocity and power improve at altitude (García-Ramos. 2016) - For long altitude training has been thought of (especially by non-athletes) as a PEDish (performance enhancing drug) performance enhancer. More recently, however, several studies have shown that the benefits may - as in so many other cases - be significantly overrated.
In a recent study, scientists did now aim (a) to analyze the effect of an acute exposure to terrestrial altitude on the force-velocity relationship parameters (maximum force [F0)], maximum velocity [V0)], and maximum power [P0)]) during a loaded squat jump (SJ), and (b) to compare unloaded SJ and countermovement jump (CMJ) performance between sea level and altitude conditions. Seventeen international swimmers were tested at sea level (295 m asl) and 7 days later at terrestrial altitude (2320 m asl) during their first 24 hours of altitude exposure. The maximum values of force and velocity were recorded during a loaded SJ (25-100% of body weight) to determine F0, V0, and P0 parameters.
Figure 3: Rel. (in %) and Effect Size ES for inter-group differences (Garcia-Ramos. 2016)
"These results highlight the potential effect of an acute exposure to terrestrial altitude on enhancing vertical jump performance," the authors highlight and explain: "The increase in maximal power of the leg muscles at altitude is caused by an improvement in the theoretical maximal velocity at which lower limbs can extend with no significant changes for the theoretical maximal force" (Garcia-Ramos. 2016).
- Brunell University. "Cardiovascular & Respiratory Physiology Research Group." College of Health and Life Sciences < http://www.brunel.ac.uk/chls/life-sciences/sport-health-and-exercise-sciences/research/csmhp/physiology >
- Burtch, et al. "Controlled Frequency Breathing Reduces Inspiratory Muscle Fatigue." Journal of Strength & Conditioning Research: Post Acceptance: August 16, 2016 - doi: 10.1519/JSC.0000000000001589
- Carlson, L. "Salivary Lymphocyte Responses Follwing Acute Anaerobic Exercise In A Cool Environment." Journal of Strength & Conditioning Research: Post Acceptance: August 16, 2016 - doi: 10.1519/JSC.0000000000001593
- García-Ramos, A. "The maximal mechanical capabilities of leg extensors muscles to generate velocity and power improve at altitude." Journal of Strength & Conditioning Research: Post Acceptance: August 16, 2016 - doi: 10.1519/JSC.0000000000001592
- Harris, N. "Acute Responses To Resistance And High Intensity Interval Training In Adolescents." Journal of Strength & Conditioning Research: Post Acceptance: August 16, 2016 - doi: 10.1519/JSC.0000000000001590
- Schimpchen, et al. "Can cold water immersion enhance recovery in elite Olympic weightlifters? An individualized perspective." Journal of Strength & Conditioning Research: Post Acceptance: August 16, 2016 - doi: 10.1519/JSC.0000000000001591