Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle
- Coffey, V. G., Pilegaard, H., Garnham, A. P., O'Brien, Brendan, Hawley, J. A.
- Authors: Coffey, V. G. , Pilegaard, H. , Garnham, A. P. , O'Brien, Brendan , Hawley, J. A.
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 106, no. 4 (2009), p. 1187-1197
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- Description: We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men [22.9 ± 6.3 yr, body mass of 73.2 ± 4.5 kg, peak O2 uptake (V̇O2peak) of 54.0 ± 5.7 ml·kg-1·min-1] were randomly assigned to complete trials consisting of either resistance exercise (8 x 5 leg extension, 80% 1 repetition maximum) followed by a bout of endurance exercise (30 min cycling, 70% V̇O2peak) or vice versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout, and after 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1Ser473 were elevated 15 min after resistance exercise compared with cycling, with the greatest increase observed when resistance exercise followed cycling (∼55%; P < 0.01). TSC2-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (-42%), whereas muscle ring finger mRNA was elevated when cycling was undertaken after resistance exercise (∼52%; P < 0.05). The hexokinase II mRNA level was higher after resistance cycling (∼45%; P < 0.05) than after cycling-resistance exercise, whereas modest increases in peroxisome proliferator-activated receptor gamma coactivator-1α mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates acute "interference." Copyright © 2009 the American Physiological Society.
- Description: 2003008129
- Authors: Coffey, V. G. , Pilegaard, H. , Garnham, A. P. , O'Brien, Brendan , Hawley, J. A.
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 106, no. 4 (2009), p. 1187-1197
- Full Text:
- Reviewed:
- Description: We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men [22.9 ± 6.3 yr, body mass of 73.2 ± 4.5 kg, peak O2 uptake (V̇O2peak) of 54.0 ± 5.7 ml·kg-1·min-1] were randomly assigned to complete trials consisting of either resistance exercise (8 x 5 leg extension, 80% 1 repetition maximum) followed by a bout of endurance exercise (30 min cycling, 70% V̇O2peak) or vice versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout, and after 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1Ser473 were elevated 15 min after resistance exercise compared with cycling, with the greatest increase observed when resistance exercise followed cycling (∼55%; P < 0.01). TSC2-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (-42%), whereas muscle ring finger mRNA was elevated when cycling was undertaken after resistance exercise (∼52%; P < 0.05). The hexokinase II mRNA level was higher after resistance cycling (∼45%; P < 0.05) than after cycling-resistance exercise, whereas modest increases in peroxisome proliferator-activated receptor gamma coactivator-1α mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates acute "interference." Copyright © 2009 the American Physiological Society.
- Description: 2003008129
The effects of increased absolute training intensity on adaptations to endurance exercise training
- McNicol, Ashleigh, O'Brien, Brendan, Paton, Carl, Knez, Wade
- Authors: McNicol, Ashleigh , O'Brien, Brendan , Paton, Carl , Knez, Wade
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 12, no. 4 (2009), p. 485-489
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- Description: "Progressive overload" is regarded an important principle to consider in maximising endurance training adaptations, yet little scientific evidence supports this concept. The aim of the present study was to compare differences in endurance performance after a training regime where treadmill-running intensity was incrementally elevated to a regime where running intensity remained unchanged. Twenty-eight healthy untrained males and females were randomly and equally assigned into both regimes. All participants performed 20 min treadmill-running sessions 3 times a week for 6 weeks. Prior to and after training, maximum oxygen uptake (over(V, ̇) O2max), oxygen uptake and velocity at the lactate threshold (LTVO2 and LTv) and maximum treadmill velocity (Vmax) were measured in an incremental treadmill test. 5000 m time trial performance was also assessed. In the incremental intensity regime treadmill velocity commenced at 0.8 km·h-1 below the LTv and was increased by 0.1 km·h-1 every session. In the constant intensity regime treadmill speed was kept constant at 0.8 km·h-1 below the LTv for the duration of the training. The study revealed that both regimens increased over(V, ̇) O2max, Vmax LTVO2, LTv and decreased 5000 m time trial significantly after training. There were no significant differences in the changes between regimens for over(V, ̇) O2max, Vmax and 5000 m time trial. However, the increase in LTVO2 and LTv were significantly greater in the incremental intensity regime compared to the constant intensity regime. The present data show that 20 min treadmill-running sessions performed 3 times a week for 6 weeks improves endurance performance and that progressively elevating exercise intensity is important to maximise improvements in LTVO2 and LTv. © 2008 Sports Medicine Australia.
- Description: 2003008109
- Authors: McNicol, Ashleigh , O'Brien, Brendan , Paton, Carl , Knez, Wade
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 12, no. 4 (2009), p. 485-489
- Full Text:
- Reviewed:
- Description: "Progressive overload" is regarded an important principle to consider in maximising endurance training adaptations, yet little scientific evidence supports this concept. The aim of the present study was to compare differences in endurance performance after a training regime where treadmill-running intensity was incrementally elevated to a regime where running intensity remained unchanged. Twenty-eight healthy untrained males and females were randomly and equally assigned into both regimes. All participants performed 20 min treadmill-running sessions 3 times a week for 6 weeks. Prior to and after training, maximum oxygen uptake (over(V, ̇) O2max), oxygen uptake and velocity at the lactate threshold (LTVO2 and LTv) and maximum treadmill velocity (Vmax) were measured in an incremental treadmill test. 5000 m time trial performance was also assessed. In the incremental intensity regime treadmill velocity commenced at 0.8 km·h-1 below the LTv and was increased by 0.1 km·h-1 every session. In the constant intensity regime treadmill speed was kept constant at 0.8 km·h-1 below the LTv for the duration of the training. The study revealed that both regimens increased over(V, ̇) O2max, Vmax LTVO2, LTv and decreased 5000 m time trial significantly after training. There were no significant differences in the changes between regimens for over(V, ̇) O2max, Vmax and 5000 m time trial. However, the increase in LTVO2 and LTv were significantly greater in the incremental intensity regime compared to the constant intensity regime. The present data show that 20 min treadmill-running sessions performed 3 times a week for 6 weeks improves endurance performance and that progressively elevating exercise intensity is important to maximise improvements in LTVO2 and LTv. © 2008 Sports Medicine Australia.
- Description: 2003008109
Caffeine has a trivial effect on 5-km running performance
- O'Rourke, Matthew, O'Brien, Brendan, Knez, Wade, Paton, Carl
- Authors: O'Rourke, Matthew , O'Brien, Brendan , Knez, Wade , Paton, Carl
- Date: 2006
- Type: Text , Conference paper
- Relation: Paper presented at 11th annual Congress of the European College of Sport Science, Lausanne, Switzerland : 5th-8th July 2006
- Full Text: false
- Description: 2003003743
Caffeine has a small effect on 5-km running performance of well-trained and recreational runners
- O'Rourke, Matthew, O'Brien, Brendan, Knez, Wade, Paton, Carl
- Authors: O'Rourke, Matthew , O'Brien, Brendan , Knez, Wade , Paton, Carl
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 11, no. 2 (2008), p. 231-233
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- Description: The purpose of this study was to investigate if caffeine ingestion improves 5-km time-trial performance in well-trained and recreational runners. Using a double-blind placebo-controlled design, 15 well-trained and 15 recreational runners completed two randomized 5-km time-trials, after ingestion of either 5 mg kg-1 of caffeine or a placebo. Caffeine ingestion significantly improved 5-km running performance in both the well-trained and recreational runners. In comparison to the placebo trial, the caffeine trial resulted in 1.1% (90% CI 0.4-1.6) and 1.0% (0.2-2%) faster times for the well-trained and recreational runners. Reliability testing of the recreational runners indicated a test-retest error of measurement of 1.4%. We conclude that caffeine ingestion is likely to produce small but significant gains in 5-km running performance for both well-trained and recreational runners. © 2007 Sports Medicine Australia.
- Description: C1
- Authors: O'Rourke, Matthew , O'Brien, Brendan , Knez, Wade , Paton, Carl
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 11, no. 2 (2008), p. 231-233
- Full Text:
- Reviewed:
- Description: The purpose of this study was to investigate if caffeine ingestion improves 5-km time-trial performance in well-trained and recreational runners. Using a double-blind placebo-controlled design, 15 well-trained and 15 recreational runners completed two randomized 5-km time-trials, after ingestion of either 5 mg kg-1 of caffeine or a placebo. Caffeine ingestion significantly improved 5-km running performance in both the well-trained and recreational runners. In comparison to the placebo trial, the caffeine trial resulted in 1.1% (90% CI 0.4-1.6) and 1.0% (0.2-2%) faster times for the well-trained and recreational runners. Reliability testing of the recreational runners indicated a test-retest error of measurement of 1.4%. We conclude that caffeine ingestion is likely to produce small but significant gains in 5-km running performance for both well-trained and recreational runners. © 2007 Sports Medicine Australia.
- Description: C1
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