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E L Fox

Publications and source records attributed to E L Fox.

10 recordsLinked to original sources
PubMed1979

Interval training.

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Adenosine Triphosphate↗
PubMed1978

Specificity of metabolic and circulatory responses to arm or leg interval training.

The purpose of this study was to evaluate metabolic and circulatory responses to interval training of legs or arms during steady-state, submaximal cycling. 15 college males cycled on a bicycle ergometer twice with arms (63 and 83 W) and twice with legs (100 and 125 W) before and following 5 weeks of daily interval training. Seven subjects trained with arm cycling and eight with leg cycling. Significant post-training decreases in submaximal oxygen consumption (VO2), heart rate (HR), and venous blood lactate (LA(V)) were noted when cycling with trained and untrained muscles with the magnitude of change significantly greater with trained muscles. These results indicate metabolic and circulatory adaptations to interval training that are mediated centrally and peripherally. With respect to HR, but not VO2, training a larger muscle mass (legs) produced a greater central but lesser peripheral effect whereas the opposite was true for the smaller arm muscles. The data also suggested that the peripheral adaptation involves a common mechanism controlling both HR and LA(V)) changes with a separate mechanism controlling VO2.

Adolescent↗
PubMed1978

Metabolic responses of females to high intensity interval training of different frequencies.

The purpose of this investigation was to examine the effects of frequency and distance of high intensity, interval training on females. Thirty-two females participated in an eight-week program of interval run training. Subjects were assigned to either a 2 day/week or a 4 day/week group, as well as a high intensity, short distance (50,101,201 meters), or high intensity longer distance (604, 805, 1208 meters) group. Estimates of training intensity were 170% and 130% Vo2max for the short and longer distance groups, respectively. Maximal and submaximal measures of oxygen consumption (Vo2), heart rate (HR), and venous blood lactic acid were determined prior to and following the training program. After training, there was a significant increase (P less than 0.01) in Vo2max (13%) (deltax = 0.32 1/min or 5.2 ml/kg.min). Maximal VE increased approximately 12% after training (P less than 0.01). Max HR, max lactic acid, and submax Vo2 were not altered by the training. However, HR submax decreased significantly (P less than .05) after training by approximately 6%. Analysis of coveriance indicated that these changes were independent of training frequency, distance, and intensity. It was concluded that the changes in aerobic power and submaximal HR of females are independent of frequency, distance, and intensity of high-intensity interval training programs.

Adult↗
PubMed1977

Metabolic responses to interval training programs of high and low power output.

The metabolic responses of 30 college-aged males were compared following high power (30-sec runs with 19 repetitions-Group HP) and low power (120-sec runs with 7 repetitions-Group LP) interval training programs (8-wk, 3 days/wk). Measurements included: maximal aerobic power (Vo2max, open circuit spirometry); maximal lactacid capacity (net-LAmax, blood LA accumulation following exhaustive exercise); net energy production (net Vo2 and netLA) following a 2-min run that was exhaustive before but not following training; and maximal muscular power (stair-climbing procedure). The results indicated: 1) significant but equal increases in Vo2 max in both groups; 2) no change in either group in netLAmax; 3) net Vo2 during the 2-min run was unchanged, however, netLA was significantly greater in Group LP; 4) no changes in either group in muscular power. It was concluded that low power and high power output interval training programs elicit similar changes in maximal aerobic and anaerobic metabolism, and that the physiological and or biochemical changes responsible for lowered lactic acid production during heavy, but submaximal exercise following training are produced to a greater extent by the low power program.

Adolescent↗
PubMed1975

Frequency and duration of interval training programs and changes in aerobic power.

This study was designed to ascertain whether 7- and 13-wk interval training programs with training frequencies of 2 days/wk would produce improvement in maximal aerobic power (VO2max) comparable to that obtained from 7- and 13-wk programs of the same intensity consisting of 4 training days/wk. Sixty-nine young healthy college males were used as subjects. After training, there was a significant increase in VO2max (bicycle ergometer, open-circuit spirometry) that was independent of both training frequency and duration. However, there was a trend for greater gains after 13 wk. Maximal heart rate (direct lead ECG) was significantly decreased following training, being independent of both training frequency and duration. Submaximal VO2 did not change with training but submaximal heart rate decreased significantly with greater decreases the more frequent and longer the training. Within the limitations of this study, these results indicate that: 1) maximal stroke volume and/or maximal avO2 difference, principle determinants of VO2max, are not dependent on training frequency nor training duration, and 2) one benefit of more frequent and longer duration interval training is less circulatory stress as evidenced by decreased heart rate, during submaximal exercise.

Adult↗
PubMed1975

Oxygen cost during exercise in simulated subgravity environments.

Oxygen cost (VO2) and heart rate (HR) were determined during treadmill walking in simulated subgravity environments. The long axis of the subject's body was suspended parallel to the floor in a slow rotation room with feet aligned on the surface of a treadmill mounted 90 degrees on the wall. Without rotation, the subjects were virtually weightless against the treadmill; with centrifugation, environments of 0.25, 0.5 and 1 G were simulated. VO2 (open circuit) and HR (ECG) were measured during the 5th minute of walking at 3.2, 4.7 and 6.1 km/h. Similar measurements were also determined during walking at 1/2-G using the inclined plane technique. VO2 per unit mass and HR were significantly reduced in all subgravity environments. However, net VO2 per unit weight carried and, therefore, mechanical efficiency was found to be independent of gravity. This supports the idea that the most probable cause for the decreased O2 cost with reduced gravity is less body weight carried.

Adult↗