HOGERVORST, Eef; BANDELOW, Stephan; SCHMITT, Jeroen; JENTJENS, Roy; OLIVEIRA, Marta; ALLGROVE, Judith; CARTER, Tom; GLEESON, Micheal

The aim of this study is to examine the effect ingesting a caffeine containing performance bar before and during cycling exercise, has on physical and cognitive performance.

24 trained cyclists consumed either a performance bar containing 45 g of carbohydrate and 100 mg of caffeine (CAF), a noncaffeine performance bar (CHO), or 300 mL of placebo beverage (BEV) immediately before performing a 2.5 hour 60% VO2 max cyclefollowed by a time to exhaustion trial (T2EX) at 75% VO2max. The athletes consumed the same products again after 55 and 115 min of exercise.

Cognitive function measures (computerized Stroop and Rapid Visual Information Processing tests) were performed before, during (at 70 and 140 minutes) and 5 minutes after completion of the T2EX ride.

Participants who consumed the Caffeine bar were significantly faster in comparison to those who with the CHO group, on both computerized tests, particularly after 140 min and after the T2EX ride. The placebo groups (BEV) performance was significantly slower than both treatment groups. T2EX was longer after Caffeine consumption compared with both CHO and BEV trials, and T2EX was longer after CHO than after BEV. No differences were found in the ratings of perceived exertion, mean heart rate, and relative exercise intensity.

Caffeine consumption can significantly improve endurance performance and complex cognitive ability during and after exercise. These effects may be important for athletes who’s sport requires high endurance and concentration levels.

Medicine & Science in Sports & Exercise. 40(10):1841-1851, October 2008

MCKEON, Patrick O; INGERSOLL, Christopher D; KERRIGAN, D. Casey; SALIBA, Ethan; BENNETT, Bradford C; HERTEL, Jay The aim of this trial was to determine what effect a 4-week balance training program has on static and dynamic postural control and functional outcomes in those with chronic ankle instability (CAI).

31 young adults with CAI were randomly assigned to an training group (6 males and 10 females) or a control group (six males and nine females). Balance training consisted of a 4-week supervised program that emphasised single-limb stance dynamic stabilisation. Outcome measures include: self-reported disability on the Foot and Ankle Disability Index (FADI) and the FADI Sport scales; summary center of pressure (COP) excursion measures; time-to-boundary (TTB) measures of postural control including the absolute minimum TTB, mean of TTB minima, and SD of TTB minima in the anteroposterior and mediolateral directions with eyes open and closed; and reach distance in the anterior, posteromedial, and posterolateral directions of the Star Excursion Balance Test (SEBT).

The group who underwent the training program had significant improvements in the FADI and the FADI Sport scores, in the degree and the variability of TTB measures with eyes closed, and in reach distances with posteromedial and posterolateral directions of the SEBT. Just one of the summary COP-based measures changed significantly following training.

Balance training significantly improves self-reported function, static postural control, and dynamic postural control. TTB measures were more sensitive at detecting improvements in static postural control compared with summary COP-based measures.

Medicine & Science in Sports & Exercise. 40(10):1810-1819, October 2008.

H. Himmelreich, L. Vogt, W. Banzer

The aim of this study was to compare electrical patterns of gluteus maximus activity during walking (at 0 and 10 degrees elevation) and a stair climb task in healthy men and in men with chronic lower back pain (CLBP).

Electrical activity of the glut max of twelve male CLBP patients and twenty control subjects was compared during level walking , uphill walking and stair climbing. EMG was tested on either side of the lower back, chosen at random.

Compared to level walking, incline walking and stair ascent induced a significant increase of about 25% respectively 50% of gluteus maximus activity in the healthy cohort. However, CLBP patients showed an average increase of only 35% in incline walking and stair climbing along with a longer stance phase activity during stair ascent.

The results show that low back pain is associated with changes in the level and duration of glut max activity in different walking patterns. These changes point towards a compensatory recruitment pattern to achieve a degree of lumbo-pelvic stabilisation.

Back and Musculoskeletal Rehabilitation, volume 21, number 3 / 2008

G. W. Davison;  C. McClean;  J. Brown;  S. Madigan;  D. Gamble;  T. Trinick; E. Duly 

This study aimed to look at the effect of drinking a commercially available carbohydrate-electrolyte (CHO-E) drink on exercise performance. Ten healthy male volunteers completed 3 trials in random order at least 7 days apart. During each trial, the men consumed 8 ml per kg of body weight of either a CHO-E solution (6% carbohydrate, 50 mg sodium/500 ml), a non-CHO-E placebo, or no fluid, 15 minutes before exercise.

The exercise used was intermittent shuttle running (20 m apart) for 1 hr. They then performed an incremental shuttle running test to exhaustion. The subjects displayed longer exercise times when they had consumed the CHO-E solution, compared with placebo or no fluid.

This investigation indicates that drinking a CHO-E solution 15 minutes prior to exercise improves performance.

Research in Sports Medicine, Volume 16, Issue 3, July 2008 , pages 155 - 166

Lee, Jason K.W.; Shirreffs, Susan M.; Maughan, Ronald J

The purpose of this study was to investigate the effect of drink temperature on cycling capacity in the heat.On two separate trials, eight males cycled at 65-67% VO2peak up to exhaustion in hot (34.8-35.2 degrees C) and humid (59-61%) conditions. The cyclists drank three x 300-mL solutions of either a cold (4 degrees C) or a warm (37 degrees C) drink during 30 min of seated rest before exercise. They also consumed 100 mL of the same drink, at the same temperature every 10 mins during exercise. Measurements of rectal and skin temperatures, heart rate, and sweat rate were taken. Ratings of thermal sensation and perceived exertion were assessed.

Time to exhaustion was longer with the cold drink than with the warm drink. Rectal temperature also fell at the end of the resting period after ingestion of the cold drinks. Mean skin temperature was lower from 20 mins onwards during exercise with ingestion of the cold drink than with the warm drink. Heart rate was lower before exercise and for the first 35 min of exercise with ingestion of the cold drink than with the warm drink. Drink temperature influenced sweat rate, with those having consumed the cold drink, sweating at a slower rate. Ratings of thermal sensation and perceived exertion during exercise were lower when the cold drink was ingested.

Medicine & Science in Sports & Exercise. 40(9):1637-1644, September 2008Compared with a drink at 37 degrees C, the ingestion of a cold drink before and during exercise in the heat reduced physiological strain during exercise, leading to an improved endurance capacity.

Stuart Goodall and Glyn Howatson

The aim of this investigation was to observe the effect of repeated cold water immersions (CWI) in recovering from exercise induced muscle damage. A randomised group consisting of eighteen males, completed 100 drop jumps. Following this, participants were randomly but equally assigned to either a 12 min CWI (14-16 degrees C) group who experienced immersions immediately post-exercise and then every 24 h for the next 3 days, or a control group. Maximal voluntary contraction (MVC) of the quadriceps, creatine kinase activity (CK), muscle soreness (DOMS), range of motion (ROM) and limb girth were measured pre-exercise and then for the next 4 days, every 24 hours. In addition MVC was also recorded immediately after exercise.

Significant time effects were seen for MVC, CK, DOMS and limb girth indicating muscle damage was evident, however there was no group difference or interaction observed showing that CWI did not ease any of the effects of the exercise. These results show that repeated CWI does not improve recovery from a bout of damaging eccentric contractions.

Journal of Sports Science and Medicine (2008) 7, 235 - 241

Deiary Kader, Sarkhell Radha, Paul A. Banaszkiewicz, Margaret Stocker, Lori Dunbar-Smith, Francis W. Smith

The aims of this study is to investigate the value of stabilisation exercises using a gym (swiss) ball in paraspinal muscle activation. This was achieved by measuring changes in muscle signal intensity on MRI before and after exercise.

Twenty-four healthy volunteers, 13 females and 11 males had special sequence MR images of the lumbar spine showing an axial section of the paraspinal muscles at L4/5 level. All were then guided through 10 minutes of exercise on the gym ball followed by repeat MRI scans immediately, 5 and 10 minutes post exercise. Differences in the signal intensity in multifidus, erector spinae and psoas muscles were evaluated using MRI software.

Results: The mean signal intensity in the MR images of the multifidus and erector spinae muscles significantly increased after exercise. There was no statistically significant change in the signal intensity of the psoas muscle. The study draws the conclusion that multifidus and erector spinae muscles of healthy individuals can be activated by performing certain exercises on the gym ball.

Journal of Back and Musculoskeletal Rehabilitation, Volume 21, Number 2 / 2008